Coleoptera Part 2.
This is a small family of beetles, which are characterized by soft elytra (flexible to the touch) that bare a number of short erect hairs giving it a velvety appearance. The elytra are broader towards the rear and the antennae are slightly serrate or saw-like in appearance. The basal segments of the antennae are swollen. The most common genus is Collops sp., which is predatory as an adult on a variety of insects, including the corn leaf aphid, larva of the alfalfa weevil and eggs of the Say’s stinkbug. This insect is quite common in cotton and alfalfa fields in California.
Female Collops beetle, a common predator feeding on a variety of pest insects. Image courtesy of Univar Inc.
This is one of the largest families of beetles with 40,000 species worldwide and over 2,500 species in North America. They are very active, long legged, nocturnal beetles that typically are found under rocks and debris during the day. They are mostly black in color with large eyes and forward projecting sickle-shaped mandibles. Many have parallel lines of pits (striations) running the length of the elytra. Almost all members of this family are predatory in both the adult and larval stages and some are important enemies of slugs, snails and insect pests.
All carabids except the quite primitive flanged bombardier beetles have a groove on their foreleg tibiae bearing a comb of hairs. This is used for cleaning their antennae. Ant nest beetles, known also as flanged bombardier beetles are mostly predators on ant larvae and workers. They are characterized by moderate size (6-20 mm), by glandular hairs that produce secretions attractive to ants and by the odd antennal structures of many species.
Flanged Bombardier Beetle.
The head of a ground beetle illustrating the sickle-shaped mandibles and enlarged eyes. Image courtesy of VoPak, Inc.
Hunters and Searchers-Calcosoma spp. This genus contains a number of very large (up to 1 inch in length) robust beetles that have a characteristic body shape (Figure`120). A number of species either as larvae or adults or both active seek their prey in trees. Calcosoma. sycopantha was imported from Europe and introduced into the New England states for control of the gypsy moth, one of our most important forest pests. Most members of this genus prey on caterpillars and other larvae including cutworms, armyworms, tent caterpillars, bollworms, cotton leaf worm, cabbage loppers and many more. One beetle is capable of devouring up to 50 caterpillars in a period of a few weeks. Some adults are long lived, surviving for up to 5 years.
A representative of one of the many species in the genus Calcosoma. Image courtesy of Ron Billings, Texas Forest Service.
Bombardier Beetles. A number of Carabidae posses well developed defensive secretions. Most have paired pygidial glands in the lower back of the abdomen that produce noxious or even caustic secretions used to deter would-be predators. In some, commonly known as bombardier beetles, these secretions are mixed with volatile compounds and ejected by a small combustion, producing a loud popping sound and a cloud of hot and acrid gas which can injure small mammals and kill invertebrate predators. To humans, getting "bombed" by a bombardier beetle is a decidedly unpleasant experience. The "bombing" ability has evolved independently twice as it seems – in the flanged bombardier beetles which are among the most ancient ground beetles, as well as in which are part of a more "modern" lineage. Other groups of ground beetles mechanically squirt their defensive secretions for considerable distances and are able to aim with a startling degree of accuracy; in Afrikaans they are known as oogpisters ("eye-pissers"). In one of the very few known cases of a vertebrate mimicking an arthropod, juvenile Heliobolus lugubris lizards are colored similar to the aposematic oogpister beetles, and move in a way that makes them look surprisingly similar to the insects at a casual glance.
Bombardier Beetle on the Attack.
It is sometimes suggested that Charles Darwin found himself on the receiving end of a bombardier beetle's defenses on a collecting trip in 1828, but this is based on a misreading of his autobiography; a bombardier beetles' "bombing" is already triggered by picking it up, and Darwin had been carrying the beetle in question in his closed hand for some time already before he ran afoul of its secretions. He discussed this incident and another such case in a letter to Leonard Jenyns as follows:
"A Cychrus rostratus once squirted into my eye & gave me extreme pain; & I must tell you what happened to me on the banks of the Cam in my early entomological days; under a piece of bark I found two carabi (I forget which) & caught one in each hand, when lo & behold I saw a sacred Panagæus crux major; I could not bear to give up either of my Carabi, & to lose Panagæus was out of the question, so that in despair I gently seized one of the carabi between my teeth, when to my unspeakable disgust & pain the little inconsiderate beast squirted his acid down my throat & I lost both Carabi &Panagæus!"
Members of this family are commonly confused with the ground beetles. This is because most members of both families are fairly large and brown or black in color: however, beyond that, little similarities exist. Many members of this family have moniliform antennae, while the ground beetles have filiform antennae. In addition darkling beetles feed on a variety of plant material while the ground beetles are predatory. As a result the position of the mandibles is quite different. In predatory beetle the mandibles project forward (referred to as prognathus). This gives the front of the head a pointed appearance and an advantage in catching their prey. In the darkling beetles the mandible are referred to as hypoganthus, which simply mean that they point downward or toward the ground. In this case the front of the head is blunt. An additional behavioral difference between the two families is that because ground beetles are predatory they are fast moving. On the other hand, darkling beetles are slow moving. You don’t have to be very fast to run down a dead leaf.
Stink Beetles. Some members of this family are commonly referred to as stinkbugs or stink beetles. If disturbed, these beetles will characteristically raise their abdomens in the air and produce a strong smelling defensive secretion. An addition behavioral characteristic of many of the ground beetles is that when disturbed they play dead.
A stink beetle with abdomen raised.
Iron Cad Beetles. These beetles are apparently fungus feeders as adults and associated with rotting wood, and as the common name implies, have one of the hardest of all arthropod exoskeletons; in some species, it is almost impossible to drive an insect pin through their bodies without using a small drill to make a hole first. They can be stepped on with any harm. Some species in Mexico are decorated with costume jewelry glued to their bodies, and sold as living brooches, known as ma'kech, to be worn on one's clothes. They are very long-lived as adults and when not used as jewelry they can be kept on wet bark to maintain their maximum length of survival.
Left. Common iron clad beetle found in California. Right. Mexican species with attached jewels. Image courtesy of Shawn Hanrahan
Some species of darkling beetles will play dead when disturbed. They fall down and become very rigid often with legs extended. They will remain in this position for several minutes. Apparently this is a defensive behavior in order to avoid a potential predator. Many predators recognize their prey by movement.
A typical defensive position of some of the so-called stinkbugs, a group of darkling beetles.
Probably the best known of all the darkling beetles is the yellow mealworm. This insect is the largest (around 0.3 in.) of the stored product and grain pests, but is better known in the pet trade as a food source for any of a variety of lizards, fish and arthropods. Mealworms are typically used as a food source for reptile, fish, and avian pets. They are also provided to wild birds in bird feeders, particularly during the nesting season when birds are raising their young and appreciate a ready food supply. Mealworms are high in protein, which makes them especially useful as a food source. They are also commonly used for fishing bait.
They can be purchased at most pet stores and bait shops. They are also available via mail order and via internet suppliers (by the thousand). Mealworms are typically sold in a container with bran or oatmeal for food. When rearing mealworms, commercial growers incorporate a juvenile hormone into the feeding process to keep the mealworm in the larval stage and achieve an abnormal length of 2 cm or greater.
Tenebrio molitor is also used for biological research. It's relatively large size, ease of rearing and handling, and status as a non-model organism make it an attractive organism for proof-of-principle study. Researchers worldwide, but particularly in Sheffield (UK) and Pusan (Korea), currently use this beetle as a model system for studies in biology, biochemistry, evolution, immunology and physiology.
Mealworms may be easily raised on fresh oats, whole wheat bran or grain, with sliced potato or carrots and little pieces of apple as a water source. They have been incorporated into tequila flavored novelty candies. However, mealworms are not traditionally served in tequila or mezcal drinks, the latter sometimes containing a larval moth (Hypopta agavis).
Life cycle of the yellow mealworm. Image courtesy of Jim Kalisch, Nebraska University Entomology.
Superworms-Zophobas morio. This is a species of darkling beetle, whose larvae are known by the common name superworm or zophobas. Superworms are common in the reptile pet industry. In the search for easy to raise insects to use as food for captive reptiles and amphibians, superworms quickly moved into the spotlight, and have been a staple feeder insect ever since.
These insect larvae resemble very large mealworms, about 1 1/2 to 2 1/4 inches long. Once they reach adult size, the larvae pupate, and later emerge as large, black beetles. The larvae will not pupate if kept in a container with many other larvae, where they receive constant bodily contact. Keeping superworms this way is commonly used to hinder pupation.
Superworm. Image Courtesy of André Karwath.
Superworms are readily accepted by lizards, turtles, frogs, salamanders, birds, and other insectivorous animals. Their hard chitin may make them less suitable for arachnids and some predatory insects. Their nutritional values are similar to those of mealworms, so supplementation with calcium is necessary if they are used as a staple food item. They are odor-free (but the beetles release some odor if provoked), and can be easily contained with little to no risk of escapes, making them ideal for raising at home to feed a collection of captive insectivores.
Superworms are often chosen as an educational project for children. Their large size and easy care make them excellent classroom subjects for demonstrating insect life cycles with a complete metamorphosis. The worms can give a pinch if handled roughly, so handling should be supervised, but they do not bite hard enough to break skin. The beetles do not bite. The defensive odor emitted by the adult beetles will add an additional lesson to the project.
Both the larvae and the beetles of superworms are very sensitive to tobacco smoke and some incense. Even small amounts of tobacco smoke (ie smoking a cigarette in the same room as the insects are kept) will make them show some hyperactivity. Smoking should therefore be kept to a minimum in order to breed healthy individuals.
Breeding. Larvae and beetles both will eat just about anything, although to ensure that they are healthy insects for feeding purposes, they should be given healthy and clean food. Examples of preferred food include:
§ Fruit (also provides water)
§ Peels (that are not from vegetables/fruit that are commonly treated with insecticides, including bananas and oranges).
Breeding of superworms can be started with just a small number of individuals. It is best to take full-grown larvae, each one by itself into an empty film container with some small holes in the lid. There should be some wooden flakes in the container but there is no need for food, as long as the individual is in its full-grown larva state. The lid is put on the container and containers are kept dark at room temperature in a not too moist atmosphere (as this could cause fungus and mold attacks).During the pupated state the larva will not actually spin itself into a cocoon, but it will go into a resting state where it will only move if it is disturbed physically, and then only by twisting back and forth. Some of the larvae might prove not to go into the resting state. In a few weeks most of the larvae will begin to molt. First they will molt into a pupa, resembling half larvae half beetle. This pupa will usually remain quite light colored. After this the pupa will emerge as a beetle.
At first the beetle will be very light yellow in color, before turning black. It should be left and kept alone until it has become totally black, since this indicates that the exoskeleton has hardened and it is no longer at risk of being eaten by other beetles. The beetles should be kept in a more spacious container separate from the worms, and for egg-laying, either with some wood with bark on it or on a 1 mm-hole mesh-frame placed on a bed of wood flakes.
Eggs laid on the bark or in the flakes will soon develop into very tiny (appoximately 0.5 mm) larvae. The beetles should then be removed, or if a mesh is used, simply lift the frame out with the beetles on it. The larvae will grow very fast. For fastest breeding they can be kept in a quite small container, where they always will have body contact with another individual. Keeping them this way will also prevent them from pupating.
To prevent cannibalism the larvae should be given enough food. It is also important to see that there is not too much moist food in the container, as this can cause the exoskeleton of the larvae to soften, making them prone to be eaten by other individuals. If it becomes apparent that their exoskeletons have begun to soften due to humidity, it is possible to dry the worms by adding sawdust or wooden flakes to the breeding container.
Confused Flour Beetle, Tribolium confusum. This is a common pest insect known for attacking and infesting stored flour and grain. They are one of the most common and most destructive insect pests for grain and other food products stored in silos, warehouses, grocery stores, and the home.]
The confused flour beetle is very similar in appearance and habit to the red flour beetle, Tribolium castaneum and the destructive flour beetle, Tribolium destructor. In fact, this similarity and the resulting confusion over the identity of the beetle is the origin of its name. Both the confused flour beetle and red flour beetle are small, about 1/8 to 1/4 inch in length, and reddish-brown in color. The primary distinguishing physical difference is the shape of their antennae: the confused flour beetle's antennae increase gradually in size and have four clubs, while the red flour beetle's antennae have only three. Additionally, red flour beetles have been known to fly short distances, while confused flour beetles do not. Tribolium destructor is much darker than either and less common.
Confused Flour Beetle. Imge Courtesy of Sareto.
While confused (and red) flour beetles cannot feed on whole, undamaged grain, they are often found in large numbers in infested grains, feeding off of broken grain, grain dust, and other household food items like flour, rice, dried fruit, nuts, and beans. Both types of beetles are often found not only in infested grains, but in crevices in pantries and cabinets as well. Damage to food is caused somewhat by the beetles' feeding, but also by their dead bodies, fecal pellets, and foul-smelling secretions. In addition to creating a foul odor, the beetles' presence encourages the growth of mold.
Namib Desert Beetle. This master of survival dwells in one of the most arid areas with only one and half inch (40 mm) of rain per year, and has developed a unique technique to survive by obtaining water from early morning fogs. It drinks by the means of its own bumpy back surface, which provides for accumulation of water droplets of fifteen to twenty micrometers in diameter.
Namib Desert Beetle. Image Courtesy of Hans Hillewaert.
To drink water, the Namib beetle (genus Stenocara) stands on a small ridge of sand. Facing into the breeze, with its body angled at forty-five degrees, the beetle catches fog droplets on its hardened wings. Its head faces upwind, and its stiff, bumpy outer wings are spread against the damp breeze. Minute water droplets from the fog gather on its wings; there the droplets stick to hydrophilic bumps, which are surrounded by waxy, hydrophobic troughs. Droplets accumulate and coalesce until their combined weight overcomes the water's electrostatic attraction to the bumps as well as any opposing force of the wind; in a ten-mile-an-hour breeze, such a droplet would stick to the wing until it grows to roughly two-tenths of an inch in diameter; at that point it would roll down the beetle's back to its mouth parts.
The water droplets in fog are, on average, just one one-thousandth of an inch across, and the largest ones are only twice that size. The droplets are so small, in fact, that they often don't fall downward; instead they get carried sideways or even upward by currents of wind. The trick to drinking fog is getting the droplets to aggregate, so that wind and electrostatic forces no longer overwhelm gravity. When a wind-blown fog droplet lands on a hydrophilic (water-loving) surface, such as clean glass or stone, the drop flattens out because of the electrostatic attraction between the molecules of water and those of the surface. The cross section of the flat drop is too small for the wind to pick it back up. And, because water molecules so strongly attract each other, the flat drop also presents a highly hydrophilic surface to which other droplets can attach.
This is a rather small family in term of number of species but quite large in terms of the size of the individual insects. Most meloids are ¾ inches or larger, soft body with a narrow neck and deflexed head. The soft bodied characteristic refers to a flexible elytra. With most beetles the elytra is hard and inflexible.
Typical blister beetles illustrating deflexed head, narrow thorax and elongated body. Left image courtesy of Clemson University Entomology.
Blister beetles are so called for their defensive secretion of a blistering agent, cantharidin. There are approximately 7,500 known species worldwide. Many are conspicuous and some aposematically (warning coloration) colored, announcing their toxicity to would-be predators. Cantharidin is a poisonous chemical causing blistering of the skin. It is used medically to remove warts and is collected for this purpose from species of the genera Mylabris and Lytta, especially Lytta vesicatoria, better known as "Spanish fly". The Spanish fly contains up to 5% cantharidin which irritates animal tissues. The crushed powder of Spanish fly is of yellowish brown to brown-olive color with iridescent reflections, of disagreeable scent and bitter flavor.
The Spanish Fly Beetle. Image courtesy of œuvre personnelle.
Spanish Fly-Lytta vesicatoria. Other species of blister beetle used by apothecaries are often called by the same name. Lytta vesicatoria is sometimes incorrectly called Cantharis vesicatoria, but the genus Cantharis is in an unrelated family, Cantharidae. The beetle contains up to 5% cantharidin which irritates animal tissues. The crushed powder of Spanish fly is of yellowish brown to brown-olive color with iridescent reflections, of disagreeable scent and bitter flavor.
Spanish fly, or cantharides as it is sometimes called, is often given to farm animals to incite them to mate. The cantharides excreted in the urine irritate the urethral passages, causing inflammation in the genitals and subsequent priapism (sustained erection). For this reason, Spanish fly has been given to humans for purposes of seduction; they help men keep a longer erection. It is dangerous since the amount required is minuscule and the difference between the effective dose and the harmful dose is quite narrow. Cantharides cause painful urination, fever, and sometimes bloody discharge. They can cause permanent damage to the kidneys and genitals.
Adults feed on leaves of ash, lilac, amur privet, and white willow trees; larvae are parasitic on the brood of ground nesting bees. These beetles live in scrublands and woods throughout southern Europe and eastward to Central Asia and Siberia.
Medical use of this chemical dates back to descriptions from Hippocrates. Plasters made from wings of these beetles have been used to raise blisters. In ancient China, cantharides beetles were mixed with human excrement ,arsenic and wolfsbane to make the world's first recorded stink bomb.
It is also one of the world’s most well-known aphrodisiacs:
§ Henry IV (1050–1106) is known to have consumed Spanish fly at the risk of his health.
§ In the 1670s, Spanish fly was mixed with dried moles and bat's blood for a love charm made by the magician La Voisin.
§ In the 18th century, cantharides became fashionable, known as pastilles Richelieu in France.
§ The Marquis de Sade is claimed to have given aniseed-flavored pastilles that were laced with Spanish fly to prostitutes at an orgy in 1772. He was sentenced to death for poisoning and sodomy, but later reprieved on appeal.
In Medicine & Podiatry, it is used as a topical application for treatment of benign epithelial growths including most warts.
In powder, mixed with the food, cantharide could go unnoticed. Aqua toffana, or aquetta di Napoli, was one of the poisons associated with the Medicis. Thought to be a mixture of arsenic and cantharides, it was reportedly created by an Italian countess, Toffana. Four to six drops of this poison in water or wine was enough to deliver death in a few hours.
In order to determine if a death had taken place by the effects of Spanish fly, investigators resorted to the vesicación test. One of those test methods consisted of rubbing part of the internal organs of the deceased, dissolved in oil, on the shaved skin of a rabbit; the absorption of the cantharides and its blistering effect are such that they became visible on the skin of the rabbit.
Cantharides are illegal in the United States, except for use in animal husbandry and by licensed physicians for the topical treatment of certain types of warts. Some Internet or mail order suppliers of sex stimulants advertise such products like "Herbal Spanish fly", "Mexican Spanish Fly", or "Spanish Fly Potion". Most of these products are simply cayenne pepper in capsules, sometimes blended with the powder of ginseng, kelp, ginger or gotu kola. The products with the name "Spanische Fliege (Spanish fly)" that are available in Germany represent no danger since they are diluted to the point where they contain no trace of the active substance, as they are homeopathic remedies.
Blister beetles are both destructive and beneficial. In most cases the adults are phytophagus feeding on a variety of crops including legumes, beets, potatoes, ornamental flowers, tomatoes and others. The larval stages, depending on the species, are predatory mainly on either grasshopper egg pods in the soil or attack the young of wild bees. Some consider them as parasitoids but they exhibit characteristics of both predators and parasitoids.
Lytta magister (also known as the desert blister beetle or master blister beetle) is a species of blister beetle found in southwestern North America. Typically 16 to 33 mm (0.6 to 1.3 in) in length, L. magister has a striking red head, legs and prothorax, with black elytra. They can be found in great numbers in the Mojaveand Colorado Deserts in spring, and are often seen in swarms. Females lay eggs in holes in the desert soil. The larvae are insectivorous, mainly attacking bee nests. They consume the immature host along with its provisions, and can often survive on the provisions alone, thus they are not obligatory parasitoids but rather food parasites that are facultatively parasitoid, or simply predatory. Adults feed on flowers and leaves of brittlebush.
Desert Blister Beetle. Image Courtesy of Rockpocket.
These insect exhibits hypermetamorphosis, a type of complete metamorphosis. In the case of hypermetamorphosis the larval stage not only increases in size, but unlike insects with standard complete metamorphosis, it changes form with progressive molts. These changes are associated with their mode of life. The first instar larva is called a triungulin and is silver fish-like in appearance. This form actively seeks out grasshopper egg pods in the soil or in the case of those forms that feed on wild bees may sit and wait on flower heads for these pollinators. In the latter cases, once available it attaches to the bee’s hair and is carried back to the nest. Once reaching the nest or egg pod the larvae become more grub-like and eventually legless with progressive molts-at this point all the food necessary for development is provided and legs are no longer needed. Those forms that feed on egg pods are quite beneficial in controlling these pests. One larva is capable of consuming a whole pod (30 eggs) during its development. Those forms that feed on wild bee larvae could be considered destructive because the insects are valuable pollinators.
FAMILY STAPHYLINIDAE-ROVE BEETLES.
The rove beetles are a large family (Staphylinidae) of beetles, primarily distinguished by their short elytra that leave more than half of their abdomens exposed. With over 46,000 species in thousands of genera, the group is the second largest family of beetles after the Curculionidae (the true weevils). As might be expected for such a large family, there is considerable variation among the species. Sizes range from 1 to 35 mm (1.5 inches), with most in the 2-8 mm range, and the form is generally elongate, with some rove beetles being ovoid in shape. Colors range from yellow to reddish-brown to brown to black.
Most are small with a parallel-sided body and exhibit the behavioral characteristic of turning the tip of their abdomen upward when disturbed. In the majority of these insects, the larvae and adults are predatory and a few are parasitic. These are very common insects and undoubtedly play a more important role in the biological control of pests. Common habitats include decaying vegetation, leaf litter, fungi, compost piles and around decaying carcasses.
Nairobi fly or Kenya Fly. Image Courtesy of (http://www.entomart.be/)
Nairobi fly-Paederus. This species contains a potent toxin in its haemolymph which is highly irritating to the skin. Pederin is highly toxic, more potent than cobra venom. The name Nairobi fly or Kenya Fly is applied to two species of beetle which live in East Africa, Paederus crebinpunctatus and Paederus sabaeus. They are black and red in color, and about 6–10 mm long. They live in rotting leaves where they lay their eggs. The beetles neither sting nor bite, but their haemolymph contains pederin, a potent toxin which causes blistering. The toxin is released when the beetle is crushed against the skin. People are advised to brush or blow the insect off their skin to prevent irritation. Paederus fuscipes is probably the major agent that causes linear dermatitis in northern Iran. Whereas this disease is a rural difficulty in the south, mainly in villages or small towns, it is an urban problem in northern provinces along the Caspian Sea shore. Heavy rains, sometimes brought on by El Niño events, provide the conditions for the Nairobi fly to thrive. Correspondingly outbreaks have occurred in 1998 and 2007.
Dermatitis Caused by Nairobi Fly.
Devil's Coach-Horse Beetle -Ocypus olens. This is a very common and widespread European beetle. It was originally named Staphylinus olens in 1764 and some authors and biologists still use this older name. The species has also been introduced to the Americas (including the West Coast) and parts of Australasia.
This black beetle usually shelters during the day under stones, logs or leaf litter. It is most often seen in forests, parks and gardens between April and October.
Devil’s Horse Coach Beetle in Threatening Position. Image Courtesy of Treedots. Images Courtesy of Sarefo
It is a long-bodied beetle. At about one inch in length, as in all rove beetle the elytra are short covering only its thorax, exposing the abdominal segments. The abdominal musculature is powerful and the abdominal segments are covered with sclerotized plates. It is capable of flight but its wings are rarely used. It is covered with fine black hairs.
It is well known for its habit of raising its long and uncovered abdomen and opening its jaws, rather like a scorpion when threatened. This explains one of its alternative names, the cock-tail beetle. Although it has no 'sting in its tail' it can give a painful bite with its strong pincer-like jaws. It also emits a foul smelling odor, as a defensive secretion, from a pair of white glands at the end of its abdomen. In the scientific name olens means smelling and describes this secretion.
It is a predator, hunting mainly by night, feeding on invertebrates including worms and woodlice, as well as carrion. The prey is caught in the mandibles which are also used to cut and together with the front legs to manipulate the food into a bolus. The bolus is repeatedly chewed and swallowed, emerging covered with a brown secretion from the foregut, until it is reduced to a liquid which is digested. Skin (in the case of earth worms) and hard materials (from arthropods) are left. The larvae are also carnivorous with similar eating habits.
Females lay their eggs from 2-3 weeks after first mating. They are large (4 mm) and white with a darker band and laid singly in damp conditions under moss, stones, cow pats or leaf litter, typically in the autumn. After around 30 days the eggs split and the larvae emerge, white with a straw colored head. The larva lives largely underground, and feeds on similar prey to the adult and has the same well developed mandibles. It adopts the same display with open jaws and raised tail when threatened. The larva goes through three stages of growth (instars) the final stage is approximately one inch in length. At around 150 days the larva pupates for about 35 days and emerges as an adult with its final coloring, fully formed except for the wings which cannot be folded neatly beneath the elytra for several hours. Adults can survive a second winter, some by hibernating in burrows and not emerging until March while others remain active.
This beetle has been associated with the Devil since the Middle Ages, hence its common name. Other names include Devil's footman, Devil's coachman and Devil's steed. In Ireland the beetle is known as a deargadaol (literally Devil's beast) and it is said that the Devil assumes the form of this beetle to eat sinners. As with many supposed bringers of ill-luck superstition holds that people can turn the creature's powers to their own advantage and it is said that reapers used to enclose the body of a Devil's coach horse beetle in the handle of their scythes to improve their skill. The origins of these beliefs can perhaps be explained by the beetle's threatening appearance, and its habit of eating carrion.
As their name applies these beetles are attracted to and lay their eggs on dead animals or carrion as it begins to decay. It is generally believed that these insects feed on the microorganisms that are found in this type of situation. The adults are very strong and capable of moving dead animals many times their own weight. Others dig under dead animals and bury them in order to prevent larger carrion feeders (birds, reptiles, etc.) from finding and preventing their meal.
The Silphidae is a small family of large beetles (0.5 to 0.9 inches) that can easily be distinguished by the overall shape of the adults. There are basically 2 forms in this family. In one the elytra are short leaving 2 abdominal segments visible when viewed from a dorsal angle. This form also has an abrupt (capitate) clubbed antennae and coloration can vary from black to black with bright orange to red markings. The second form is flattened with a broadly oval body and gradual clubbed antennae.
This family has two main sub-families, Silphinae and Nicrophorinae. The sub-families are divided primarily on behavioral foundations. Members of the sub-family Silphinae show little to no care for their young and breed on large carrion. Nicrophorinae breed on small carrion and will bury themselves and their food to rear their offspring in a bi-parental manner. There are approximately 183 species in this family which are found worldwide. The Nicrophorus americanus, known as theAmerican Burying Beetle, is an endangered species.
Many members of the family are flightless, but have wings. The evolutionary change is thought to be a result due to the changes in habitat over time. Researchers have found that most flight-capable species in this group feed on vertebrate carcasses, whereas flightless species will feed on soil invertebrates. They also found that egg production increased with flight loss because of a more limited food supply. The reason behind this is because with less food more offspring would die before reaching sexual maturity.
Two body forms of the carrion beetles. Top image courtesy of Troy
Bartlett. Bottom. http://popgen.unimaas.nl/~jlindsey/commanster.html
Nicrophorinae are well known for the habit of locating a carcass and burying it by unearthing the soil underneath it. The burying behavior has seemingly evolved to prevent competition from other insects such as fly maggots. It has been observed that the cooperation of the two parent beetles leads to breeding success. More likely than not a breeding pair will work together, but in cases where there is large carrion males try to boost their reproduction by emitting pheromones thus attracting additional females. In this way, he will father more offspring, but the reproductive success of the primary female steadily declines. Sometimes, where there is a large carcass the likelihood of intense competition from flies leads to communal breeding. There appears to be a truce between females who would normally compete for the males, and in these cases cooperative behavior extends to females caring for each others' offspring. At the height of breeding season pairs of beetles may compete for the carrion. The losing pair will be ejected from the carrion and if any eggs have been laid they are killed so the new female can lay her own.
The Silphidae adults feed in a saprophagous manner, which means they feed on decaying matter. The beetles colonize the carrion during all four stages of decomposition which are fresh, bloated, decay, and dry. The main areas of decomposition for adults are during both the bloated and decaying stages. The Silphidae larvae mainly inhabit during the decaying and dry stages of the carrion. The primary food source for the subfamily Silphinae is the maggot mass present on the detritus. The Nicrophorinae will colonize the body earlier in decomposition in order to avoid competition with maggots. If there is a sufficiently large maggot mass they will not colonize the carcass. The parental care exhibited by this subfamily is that the adult beetles regurgitate food into the mouths of the young larvae until they are mature. Silphinae colonize later in the decaying process and the adults eat the maggot mass, sometimes leaving little maggot evidence left to estimate a Post Mortem Interval. In the case of the sexton or burying beetles, Nicrophorinae, the adults will bury small animal carcasses and lay their eggs on it. In some species, a slight depression is made on the detritus for maturing larvae that the adult beetles feed and protect. In both subfamilies the larvae are observed to eat the decaying organic material while the adults mainly consume the maggots. Flies are the major competitor of Silphiade for detritus. If a carcass is infested with maggots, many of the Nicrophorinae will abandon the carcass while members of Silphinae will feed on the maggots.
Beetles have many different weapons available to protect them against predator attacks. The members of Silphidae have many different modifications that allow them to thrive in different ecological niches including mimesis, chemical defenses and parental care. Silphid beetles are usually dark in color consisting of gold, black and brown. This dark coloring allows them to blend in to their environment. One species of Silphidae uses a physical mean of defense. Oiceoptoma inaequalis holds its elytra over its back when it flies. The back of the elytra are bright blue and when they are exposed it makes the beetle look much larger. After landing, the beetle folds its wings and the blue color vanishes. Many Silphidae have bright orange coloring on their elytra which may serve as a warning to other predators. Some Silphidae beetles secrete a chemical from a rectal gland that consists of aliphatic acids and terpene alcohols. The secretion has a strong, foul odor and may be topically irritating to Blattodea and Diptera. The species Necrodes surinamensi ejects this secretion as a spray and can rotate the end of its abdomen to spray in all directions.
The family Scarabaeidae as currently defined consists of over 30,000 species of beetles worldwide. The species in this large family are often called scarabs or scarab beetles. The classification of this family is fairly unstable, with numerous competing theories, and new proposals appearing quite often. It is probable that many of the subfamilies listed here will no longer be recognized very much longer, as they will likely be reduced in status below subfamily rank, or elevated to family status (the latter is most likely, e.g., with the family "Melolonthidae" already appearing in some recent classifications). Other families have been removed recently, and are nearly universally accepted (e.g., Pleocomidae, Glaresidae, Glaphyridae, Ochodaeidae,Geotrupidae, Bolboceratidae)
Scarabs are stout-bodied beetles, many with bright metallic colors, measuring between 1.5 and 160 mm. They have distinctive, clubbed antennae composed of plates called lamellae that can be compressed into a ball or fanned out like leaves to sense odors. The front legs of many species are broad and adapted for digging.
The C-shaped larvae, called grubs, are pale yellow or white. Most adult beetles are nocturnal, although the flower chafers and many leaf chafers are active during the day. The grubs mostly live underground or under debris, so are not exposed to sunlight. Many scarabs are scavengers that recycle dung, carrion, or decaying plant material. Others, such as the Japanese beetle are devastating agricultural pests
The larvae are C-shaped with a well developed head capsule and long thoracic legs. Scarab larvae are found in the soil, feeding on roots of plants, decaying plant matter and dung (depending on the species). Their life cycle is relatively long typically requiring a year or more to complete development. Adults may or may not feed. There are a number or agricultural pests in this family as well as some beneficial species.
Typical robust scarab with flattened front tibia and lamellate antennae and C-shaped larva.
Green Fruit Beetle-Cotinis nitida. It occurs in the southern half of North America. They also can be found well up the East Coast of the United States extending into states such as Connecticut and Rhode Island. Adults of the figeater or green fruit beetle reach sizes of 2.0 to 3.44 cm (1.25 in). They are a dull green on the top and a brilliant iridescent green on the underside and legs. They are active during daylight hours, often congregating in the shade of trees near choice breeding grounds to find mates. They make a loud buzzing sound similar to that of large bees. Larvae grow up to 5 cm (2 in) and are thick and white with a dark head. They have six small, ineffectual legs—to move, they roll onto their backs and propel themselves upside down. At rest, they curl into a firm C shape. Adults appear during late spring, or early summer, most often in the month of June. They feed on very ripe, over ripe or soft fruits such as grapes, peaches, figs, plums, peaches and nectarines; they can't penetrate the skin of thicker fruits or of tougher greenery. More damage is done by the larvae, which thrive in decaying organic matter such as compost piles and also burrow into turf and feed on the roots of grass, where they can severely damage a lawn. Because they thrive in urban compost piles, frequent turning of the piles to expose the larvae to predators and to pick them out of the pile is the most effective nonchemical treatment.
The green fruit beetle is a day flyer and commonly is seen in summer months. Although the feeding habits of these beetles cause great stress to the homeowners, they are of little concern in agriculture as they are attracted only to ripe fruit. Fruit raised for agricultural purposes normally is picked green and allowed to ripen. The larvae of the green fruit beetle commonly are found feeding in compost piles, accumulated horse manure, rabbit droppings, and chicken feces.
Adult and larvae of the green fruit beetle, Cotinis nitida. . Right image courtesy of en Wikipedia
White Grubs. Phyllophaag. This is a very large genus (more than 260 species) of New World scarab beetles in the subfamily Melolonthinae. Common names for this genus and many other related genera in the subfamily Melolonthinae are May beetles, June bugs, and June beetles. They range in size from 8–25 mm and are blackish or reddish-brown in color, without prominent markings, and often rather hairy ventrally.
Typical Phyllophaga (white grub).
These beetles are nocturnal, coming to lights in great numbers. The adults are chafers, feeding on foliage of trees and shrubs. They may cause significant damage when emerging in large numbers. The larvae (called white grubs) feed on the roots of grasses and other plants. The insects pupate underground in the fall and emerge as adults the following spring. To test for the presence of these beetles, drenching an area of lawn with a wet substance will cause larvae to emerge at the surface. The adult beetles are very clumsy, both on land and in the air.
Flies in the family Pyrgotidae are endoparasitoids of these and related beetles. The female flies pursue the beetles in flight, laying an egg on the beetle's back under the elytra where the beetle cannot reach it. The egg hatches and the fly larva enters the body cavity of the beetle, feeding on and eventually killing the host before pupating. Wasps in numerous families are parasitoids of Phyllophaga grubs, including Pelecinidae, Scoliidae, and Tiphiidae.
Adult chafers eat the leaves and flowers of many deciduous trees, shrubs and other plants. However, their fat, white grubs (reaching 40–45 mm long when full grown) live in the soil and feed on plant roots, especially those of grasses and cereals, and are occasional pests in pastures, nurseries, gardens, and golf courses.
White grubs feeding on the roots of grasses resulting in lawns showing wilting and browning of irregular shaped areas. Certainly there could be many reasons for lawns browning, especially in late summer when most grub damage occurs. Always check the root zone of affected areas for the white, c-shaped grubs. Carefully pull back the sod in suspect areas, in particular the marginal areas where brown grass meets green grass, and look for the grubs. Usually a population of about 10 or more grubs per square foot will lead to browning of the lawn.
It should be remembered that other factors that can lead to poor rooting and are mistaken for grubs. For example, lawns in shade areas often have weak roots and are pulled-up easily. Grubs do not typically appear in shaded lawns. Once grass dies, regardless of the cause, roots will rot away and the grass is very easy to tear out. So trying to diagnose grub damage from the previous season as the cause of a dead lawn area in spring is very difficult to do, even if limited roots are found in an area of dead grass. Another sign of grubs is damage from skunks and raccoons digging up lawns in search of grubs to eat. This usually happens at night.
The grubs sometimes attack vegetables and other garden plants, e.g. lettuce, raspberry, strawberry and young ornamental trees. Injury to the roots and rootstock causes small saplings and tender tap-rooted plants like lettuce to wilt suddenly or to show stunted growth and a tendency to shed leaves prematurely. Plants growing in rows are usually attacked in succession as the grubs move along from one plant to the next. Chafer grubs feed below ground for 3–4 years before changing into adult beetles.
Lawns showing damage from grubs may be treated with an insecticide. There are a number of products available for grub control. Heterorhabditis bacteriophora nematode is an example of an alternative product for white grub control that is available. For all products, read and follow all label directions, then apply to damaged areas. Water the insecticide into the soil immediately. If treating a large area, stop after a portion has been treated and water the material in, then complete the rest of the lawn area needing treatment. Only treat in and around affected areas; grubs may only be in a small part of the lawn. Imidacloprid and halofenozide are suggested to be applied before grub damage appears. An example of a way to use these products would be to apply in July to irrigated lawns that are surrounded by dry lawns, especially when adult beetle flight is high in areas with a history of grub damage.
Spring treatment for annual white grub is not suggested since the grubs feed for a short period of time in spring and is reaching maturity, thus are not controlled easily. In addition, turf grasses are actively growing at that time so usually don’t show damage.
Japanese Beetle. This beetle is, without a doubt, the most damaging scarab beetle in the United States. It was first discovered in the U.S. in southern New Jersey in 1916. Japanese beetles occur in every state east of the Mississippi River except Florida. Its spread is apparently governed by temperature and precipitation. The beetle is adapted to a region where the mean summer soil temperature is between 64° and 82°F and winter soil temperatures are above 15°F. Also, beetles thrive in areas where precipitation is rather uniform throughout the year, averaging at least 10 inches during the summer.
Description Japanese beetle adults are slightly less than 1/2 inch long, and are shiny, metallic green. They have coppery-brown wing covers that do not entirely cover the abdomen. There are six pairs of patches of white hairs along the sides and back of the body, under the edges of the wings. Males and females have the same markings, but females are typically slightly larger. Newly hatched larvae are approximately 1/8 inch long and translucent creamy white. Once feeding begins, the hindgut appears gray to black. The typical C-shape of Japanese beetle larvae is similar to that of other white grub species.
Plants Attacked and Damage Japanese beetle adults do not damage turf but are an important pest of many other plants. They feed on foliage or flowers, and are a major pest of over 300 species of plants, including fruits, vegetables, and ornamentals, field and forage crops, and weeds. Norway and Japanese maples, birch, crabapples, purple-leaf plums, roses, mountain ash, and linden are highly preferred ornamental hosts. Adults feed on the upper surface of the foliage of most plants, consuming soft mesophyll tissues between the veins and leaving a lace-like skeleton. Often the upper canopy is defoliated first or most severely. Trees receiving extensive feeding damage turn brown and become partially defoliated.
Japanese beetle grubs feed below-ground and chew on the roots of turf and ornamentals. As result, they reduce the plants ability to take up enough water and nutrients to withstand stresses of hot, dry weather. The first evidence of grub injury in turf appears as localized-patches of pale, dying grass that displays symptoms of drought stress. As grubs develop further and feeding increases, damaged areas rapidly enlarge and coalesce to a point whereby the turf is not well-anchored and can be rolled back like carpet.
Life Cycle Japanese beetles have only one generation per year. In mid-June, as soon as they emerge, adult females mate and begin laying eggs. The adults are most active in the afternoon in full-sun. Females leave ornamental plants where they feed and mate, and burrow two to four inches into the soil (under the turf) in a suitable area to lay their eggs. Eggs hatch in about two weeks, after which grubs begin feeding on the roots of turf grass. The grubs grow quickly and by late-August are nearly full-grown (about one inch long). Mid-summer rainfall and adequate soil moisture are needed to prevent eggs and newly-hatched grubs from drying-out. Adult females instinctively select areas with higher soil moisture content to lay their eggs to ensure survival of their offspring. Older grubs are more drought tolerant and will move deeper into the soil if conditions become dry. Grubs can also withstand high levels of soil moisture, so excessive rainfall or irrigation will not affect them. As soil temperatures cool in the in the fall, and the first meaningful frost occurs, grubs begin to move deeper into the soil. Grubs overwinter in the soil about two to six inches below the surface, although some may be a deep as 20 inches. They become inactive when soil temperatures fall below 50°F. In the spring, when soil temperatures reach 50°F, the grubs begin to move up into the root-zone to resume feeding for about three to five weeks. Thereafter, the grubs stop feeding and begin creating an earthen cell whereby they transform (i.e., pupate) into adults.
Control. It is important to understand that both the adults and grubs cause damage. Japanese beetle adults are capable of migrating from other areas, thus controlling one life stage will not preclude potential problems with the other.
Physical Removal and Trapping Removing of adult beetles by hand or trapping may provide adequate protection for small plantings when beetle numbers are low. However, the presence of beetles on or in the proximity of a plant will attract more beetles. Consequently, Japanese beetle traps often attract more beetles and results in subsequent damage to plants. Because eggs and young grubs have difficulty surviving in relatively dry soil conditions, withholding irrigation during peak adult beetle flight may help to reduce grub populations. However, adequate soil moisture in late-August and September can help damaged turf recover from grub damage.
Although there are a few biological control products that allegedly control Japanese beetle grubs, the performance of these products have been inconsistent. Such products include Milky spore disease, insect-parasitic nematodes, and fungal pathogens such as Beauveria bassiana and Metarrhiizium.
Nearly all soil insecticides provide adequate control of Japanese beetle grubs. However, not all control products perform equally. The traditional approach was to apply short-residual products after eggs hatched and before grubs caused visible damage. This approach is termed "curative “control. The optimal timing for curative treatments is early to mid-August. Carbaryl (Sevin), Diazinon, and Trichlorfon are three active ingredients that all provide meaningful curative control. Although chlorpyrifos (Dursban) is labeled for grub control, it does not provide acceptable control. Due to the development of new and improved insecticide chemistries, long-residual or "preventative" controls are now available and becoming the preferred management strategy. Such control product perform is applied prior to egg lay sometime in mid to late June. Such new products include the active ingredients, imidacloprid, and thiamethoxam. The adults are about 3/8 inch long, and broadly oval with brownish elytra. This beetle was imported accidentally into New Jersey in 1861 and subsequently has spread to most states east of the Mississippi River. Both the adults and larvae are extremely damaging to a wide variety of plants. The larvae feed on roots of grasses (turf) and other plants, while the adults skeletonize leaves and feed on fruit.
The Japanese beetle is such a major pest in the eastern United States, that several western states have rather extensive programs to prevent their accidental introduction. Commercial air flights (both cargo and passenger) that come to California and other western states from the east are checked during the summer months for adult beetles. Traps baited with pheromone-like chemicals attractive to adults are placed around the state in the hope that, should this beetle become established in an isolated location, its presence would quickly be discovered. Control procedures could then be used to eradicate the pest before it became established over a wide area.
Japanese beetles, Pompilla japonica. One of the more important pests in the Eastern US. Image courtesy of Bruce Martin, Wikimedia.
Rhinocerus Beetles. The rhinoceros beetles are a common group of scarabs and among the largest known Coleoptera (some South American species reach 8 inches long). These beetles are so named because the males bear hornlike projections on their heads. One or more horns may also be present on the thorax. When 2 males of the same species come together in the presence of a female; they frequently will fight or joust with their horns. This is thought to be part of the mating ritual.
In Thailand and other countries, rhinoceros beetles frequently are collected for the purpose of fighting. Two males are placed at each end of a 10-inch section of bamboo with a female in the hollow section of the plant. Thai people frequently bet large amounts of money (several hundred dollars) on the outcome of the males' battle. Generally the largest beetle wins by knocking its opponent off the bamboo. Fighting beetles are sold on many street corners; larger specimens can be quite expensive. When we were in Northern Thailand we bought the losers for 40 cents.
Xylotrupes gideon, a species of rhinoceros commonly collected for fighting in Thailand.
Atlas beetle, Chalcosoma atlas. This is a species of beetle found in southern Asia, especially Malaysia, remarkable for its size (2 to 6 inches). As common in many insect species, the male is larger than the female and usually two males will fight for a female for mating. The Atlas beetle is, like other beetles of the genus Chalcosoma, notable for its size and the horns. The Atlas beetle differs from other Chalcosoma species (such as C. caucasus) in the end of the cephalic horn of the Atlas, which is broadened.
The larva of the Atlas beetle is known for its fierce behavior, including biting if touched. Unverified reports exist of larvae that live together fighting to the death if there's not enough space or food. In addition the adults can give a nasty bite. They also have a sharp ridge between the top of the thorax and base of the elytra. I once caught a rather large specimen and made the mistake of handling it carelessly. Needless to say it took a hunk out of my finger and in a hurry I grabbed it unfortunately in the ridge area. It arched it thorax and took another chunk of my hand. Of course needless to say in trying to remove it from my now bloody hand it grabbed me with its sharp tarsal claws and strong legs (these guys are very strong) and proceeded to rake my arm as I pulled it off.
Larva and Adult of Atlas Beetle.
The origin of the name of the Atlas beetle may be the Greek Titan Atlas or the Atlas Mountains. The fact that the Caucasus mountain range gives its name to another beetle of the same genus (C. caucasus) m
Elephant Beetles, Megasoma elephas. They are classified with the Neotropical rhinoceros beetles. Elephant beetles are black in color and covered with a coat of fine microscopic hairs. The hairs grow particularly thick on the beetle's elytra. The hairs give the beetle's body a yellowish color. Males have two horns protruding from the head and another from the prothorax. Females have no horns. The horns are used for defense in competition among males for food and mates. In size, Elephant Beetles range between 70-120 mm; males are sometimes even bigger. Males are around 2 to 3 times bigger than the females. Elephant Beetles are located in southern Texas, southern Mexico, Central America, in South American rainforests, and in parts of Australia.
Elephant Beetle. Image Courtesy of Derek Ramsey (Ram-Man)
Hercules Beetle (Dynastes hercules). This is the most famous and largest of the rhinoceros beetles. It is native to the rainforests of Central America, South America, and the Lesser Antilles (Clemson University). Their title is well deserved, with some (exceptionally rare) males reaching 6.75 inches (170 mm) in length. It is the largest of the 6 species in the Dynastes genus, and one of the largest beetles known, being exceeded in length by only two other beetles in the family Cerambycidae, Macrodontia cervicornis (specimens of 170-175 mm are known) and Titanus giganteus (also up to 170-175mm; several seven inch specimens are reputed/alleged to exist). However, if the horns are excluded, this species drops considerably farther down in the size rankings. One reason for this is that the development of the horns is allometric, as well as sexually dimorphic, and thus not strictly correlated to actual body size; it is possible for a female to be much longer, measured from eyes to abdomen, than a male, yet be considered "smaller" simply due to the absence of horns.
Hercules Beetle. Image Courtesy of Adrian Pingstone
This scarab beetle is most noted for its thoracic and cephalic horns, which can grow longer than the body of the beetle itself. This adaptation is primarily used during fights with other males. Features of this species are the numerous small black spots on the elytra and the thick hairs on the underside of the thoracic horn.
The Hercules beetle is said to be the strongest creature on earth for its size, able to carry 850 times its own body weight.
As noted above, Hercules beetles are highly sexually dimorphic, with the females generally being larger-bodied but much shorter, as they lack horns entirely. The larval stage of the Hercules beetle will last one to two years, with the larva growing up to 4.5 inches (110 mm) in length and weighing up to 120 grams. Much of the life of the larva is spent tunneling through its primary food source of rotting wood. After the larval period, transformation into a pupa, and molting, the beetle then emerges as an adult. Adults will roam the forest floor in search of decaying fruit.
Dung Scarabs. Dung scarabs exhibit a unique behavior. A male and female beetle will select a likely dung pile (usually fresh), cut out a ball of the dung and roll it away with one beetle pulling while the other pushes. The ball subsequently is buried in the ground and an egg is deposited in it. Subsequently the hatching larvae feed on the buried feces.
A male and female elephant dung scarabs rolling a dung ball.
This behavior is considered beneficial because dung scarabs, in most areas of the world, are the first insects to attack the feces of wild and domestic animals. Apparently, without this initial burrowing, dung is not readily eaten or decomposed by fungi, bacteria or other animals.
Australia is a country where the importance of this beetle was recently demonstrated; cattle have become one of the three major industries there. As most people know (possibly not!), when a cow defecates the result is a rather large, moist pile of feces (known as a cow pie to some). The only naturally occurring mammals (other than humans) in Australia are marsupials; marsupial dung is rather dry and pellet-like; consequently, there were no native dung scarabs attracted to the cow pies. Much of the range land became covered by dried cow feces over time and large tough weeds of no grazing value developed around the perimeter of each pile.
The Australian government, being quite biologically control oriented, decided to import several species of dung scarabs for dung control. This initial importation was quite successful as these imported dung scarabs readily destroyed newly formed cow pies. However, a separate problem developed when a moth became a pest on wheat. Australian officials decided to import toads to control the wheat pest. Unfortunately, the toads were attracted to the dung scarabs as well as to the moths. When a cow defecated, the toads would scurry over to sit next to the cow pies and wait for the dung scarabs’ arrival. Soon most of the imported scarabs were consumed.
Dung scarab species.
Next, the officials decided to import a larger species of dung scarab with the idea that the toads wouldn't eat such large insects. Where do you go to find large dung scarabs-Africa? When an elephant defecates!-anyway a large species of African elephant dung scarab was introduced. Unfortunately, the toads attempted to eat these scarabs also; but large beetles are quite strong and, after being swallowed, the scarabs simply ripped open the toads' stomachs and crawled out—thus killing most of them. The latter situation was not a totally bad development. The imported toad was the cane toad. This toad has become a major problem in several countries as it has extremely toxic poisons in its skin, which it readily exudes when disturbed. As a result there have been many cases of poisoning of domestic animals and humans.
A 3-inch giant African dung scarab.
Beetles, and more specifically scarabs, have been important in many ancient cultures, looming high as religious symbols. So called "pendants" in the shape of beetles are known from the late Paleolithic epoch (10,000 to 20,000 years ago). It is thought that beetles played this role partially because of their ability to fly and their importance as food. Shamans (medicine men) historically played extremely important roles in these societies and had great power. They were thought to be able to fly in the sky (in dreams and trances) and descend to subterranean hells to act as mediators between mortals and the "infernal powers." With such power being held in high esteem, it is quite apparent how a beetle such as a dung scarab could become an important religious symbol, as they also could fly and dig into the earth.
In current day shamanistic societies, the scarab still plays an important role. In some South American Indian tribes, a big dung scarab named Aksak was thought to have modeled man and woman out of clay. In a more remarkable Indian myth, an aquatic beetle plunges to the bottom of the original liquid chaos to scoop up subterranean matter to form the terrestrial earth. This original beetle was thought to be a cross between an aquatic diving beetle and dung scarab.
The dung scarab played its most famous role in ancient Egyptian culture. It was thought that a giant dung scarab was responsible for rolling the sun across the sky each day. This conclusion was based on the Egyptian priest-scholars' observation of the daily activity of the dung scarab, Kheper aegyptiorium (Figure 14M). They thought the scarab ball was something like the beetle’s eggs. They further observed that the scarab buried the dung-egg ball in the soil, which turned into worm-like creatures (larvae), eventually turning into a dead corpse-like form (pupae)—only to be reborn again as a beetle. They further concluded that what happened to the sun was not that much different than the scarab’s metamorphosis. After the giant scarab buried the sun at the end of the day (setting of the sun), the sun traveled underground from west to east, going through a metamorphosis which resulted in rebirth from a corpse like stage as the sun rose.
Figure 14M. Kheper aeqyptorium, the sacred scarab of ancient Egypt.
The priest further concluded that if the lowly dung scarab and the glorious sun could go through a metamorphosis and eventually be reborn from a corpse-like stage, why could this not be possible for humans? The recipe for rebirth then was to imitate, as closely as possible, what happens to the scarab once it enters the ground. Most crucial was the last stage (the pupa) which inspired the invention of the process of mummification. In all probability the mummy is nothing more than an imitation of a scarab pupa.
As mentioned earlier, Kheper aegyptiorium is the sacred scarab. Khepera is what Egyptians called scarabs. They were so honored as gods representing regeneration, virility and new life, that many of the kings (pharaohs) took Khepera as part of their own names. King Tut (Tutankhamun), for example, used the name of Neb Kheperu Ra. This was his "official" name. Sometimes a certain king's name would be inscribed on the back of many scarab amulets (in his honor). Some of these would be worn for hundreds of years after the king's death.
A Scarab Depicted on the Walls of Tomb KV6 in the Valley of the Kings.
The image of the scarab, conveying ideas of transformation, renewal, and resurrection, is ubiquitous in ancient Egyptian religious and funerary art.
Excavations of ancient Egyptian sites have yielded images of the scarab in bone, ivory, stone, Egyptian faience, and precious metals, dating from the Sixth Dynasty and up to the period of Roman rule. They are generally small, bored to allow stringing on a necklace, and the base bears a brief inscription or cartouche. Some have been used as seals. Pharaohs sometimes commissioned the manufacture of larger images with lengthy inscriptions, such as the commemorative scarab of Queen Tiye. Massive sculptures of scarabs can be seen at Luxor Temple, at the Serapeum in Alexandria (see Serapis) and elsewhere in Egypt.
The scarab was of prime significance in the funerary cult of ancient Egypt. Scarabs, generally, though not always, were cut from green stone, and placed on the chest of the deceased. Perhaps the most famous example of such "heart scarabs" is the yellow-green pectoral scarab found among the entombed provisions of Tutankhamen. It was carved from a large piece of Libyan Desert glass. The purpose of the "heart scarab" was to ensure that the heart would not bear witness against the deceased at judgment in the Afterlife. Other possibilities are suggested by the "transformation spells" of the Coffin Texts, which affirm that the soul of the deceased may transform (xpr) into a human being, a god, or a bird and reappear in the world of the living.
One scholar comments on other traits of the scarab connected with the theme of death and rebirth:
“It may not have gone unnoticed that the pupa, whose wings and legs are encased at this stage of development, is very mummy-like. It has even been pointed out that the egg-bearing ball of dung is created in an underground chamber which is reached by a vertical shaft and horizontal passage curiously reminiscent of Old Kingdom mastaba tombs."
In contrast to funerary contexts, some of ancient Egypt's neighbors adopted the scarab motif for seals of varying types. The best-known of these being Judean LMLK seals (8 of 21 designs contained scarab beetles), which were used exclusively to stamp impressions on storage jars during the reign of Hezekiah.
The scarab remains an item of popular interest thanks to modern fascination with the art and beliefs of ancient Egypt. Scarab beads in semiprecious stones or glazed ceramics can be purchased at most bead shops, while at Luxor Temple a massive ancient scarab has been roped off to discourage visitors from rubbing the base of the statue "for luck"
This is a relatively small family of very large beetles (0.9 to 2.0 inches). There are about 800 species described worldwide that inhabit the decaying wood in the warm forests of the world. There is only one species in North America (north of Mexico). They have a very distinctive body shape with the elytra marked with longitudinal striations. A suture divides the prothorax longitudinally. The head is narrower than the thorax, with antennae consisting of 10 antennomeres with a three-segment club. The elytra are elongate with parallel sides, and heavily striated. This family of beetles known variously as "bessbugs, "bess beetles, "betsy beetles or "horned passalus beetles". Nearly all of the 500-odd species are tropical; species found in North America are notable for their size, ranging from 20-43 mm, for having a single "horn" on the head, and for a form of social behavior unusual among beetles. Bess beetle larvae are very similar in appearance to scarab larvae except they only possess 2 pair of thoracic legs.
They are subsocial (brood caring) beetles living in groups in rotting logs. They care for their young by preparing food for them and helping the larvae construct the pupal case. Both adults and larvae must consume adult feces which have been further digested by microflora for a time; an arrangement that might be described as a sort of external rumen. In addition, they are also able to produce fourteen acoustical signals, more than many vertebrates. Adults produce the sounds by rubbing the upper surface of the abdomen against the hind wings.
Of North American species, Odontotaenius disjunctus is the familiar bessbug found throughout the eastern US and Canada, while O. floridanus has only been found in Florida on sand hills that used to be islands when Florida was flooded thousands of years ago. Ptichopus angulatus was recently discovered near the border of Mexico in Arizona. Its habitat is south to Colombia and it is commonly associated with the detritus chambers of leafcutter ant nests. Two other species were reported from Arizona at the beginning of the 20th century, but have not been seen there since that time; they may have been brought from Mexico by a train hauling firewood.
A Bess Beetle.
10. To drink water, the Namib beetle (Tenebrionidae) stands on a small ridge of sand. Facing into the breeze, with its body angled at forty-five degrees, the beetle catches fog droplets on its hardened wings.
11. Spanish fly is produced by blister beetles and contains up to 5% cantharidin which irritates animal tissues.
12. Scarab larvae are C-shaped with a well developed head capsule and long thoracic legs.
13. The feeding habits of green fruit beetles cause great stress to the homeowners but are of little concern in agriculture as they are attracted only to ripe fruit.
14. Japanese beetles have only three generation per year.