Scarab Beetles
What are they?
This is a large and very variable family of beetles which contains a wide range of species, from some of our largest beetles, to a number of root-eating species that are well-known as pests by those who cherish lawns. Despite this reputation, scarabs are an important part of the ecosystem with many species being an integral part of the decomposition cycle of both animal and vegetable matter. Other species are important pollinators and many serve as important food items to a wide range of mammals and birds. The whitish grubs of many species feed on decaying wood or live plant roots.
Identification
Identification can be compounded by the sheer number of species, but many are distinctive and familiar and can be abundant at night lights during the summer.
Overall color and markings will identify many species, while the presence or absence of hairs on the body will help to sort out some of the broader groups.Tumble Beetle Canthon species
Tumble beetles (often wrongly called tumblebugs) are small members of the dung beetle group and show a number of special adaptations that allow them to carry out their tasks. They have strong front legs with outward pointing spines for digging, and shovel-shaped heads. They may sometimes be found pushing along a small ball of dung, one member of the pair rolling the ball along, the other riding on top as if navigating. Eggs are laid in the dungball after it has been buried in the ground and larvae feed on the decaying material.
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Rainbow Scarab Phanaeus vindex
A spectacular, rainbow-colored dung beetle that is seldom seen but may be found in open, sandy areas. Females are hornless while males have either a short horn or a long horn, according to sexual status. [The picture below shows one in a specimen bottle, so the full colors cannot be appreciated here].
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Dark Hoplia Hoplia trivialis
A member of the monkey beetles, relatively small, hairy scarabs which get their name from the elongated back legs that resemble monkey arms. Adults spend much time visiting flowers to feed on pollen while larvae feed on the roots of grasses. Adults can often be found clinging to grass stems, from which they drop suddenly to the ground if approached.
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Asiatic Garden Beetle Maladera castanea
Introduced from eastern Asia. A common and often abundant species that may come to light at night in large numbers. Adults feed on the leaves of a wide range of plant species, while larvae feed on the roots of grasses.
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Grapevine Beetle Pelidnota punctata
A chunky and attractive species, easily recognized by its overall shiny, light tan color with black spots. Adults feed on grape leaves and fruit, while larvae feed on decaying wood of a wide range of species.
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Oriental Beetle Exomala orientalis
Introduced from eastern Asia. A variously-marked small scarab that often comes to light. The pronotum behind the head usualy has two dark patches, but may sometimes be more or less all dark. The wing cases are strongly and clearly grooved. Adults feed little, but larvae feed on the roots of grasses.
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Japanese Beetle Popillia japonica
Introduced from eastern Asia, with the first records in North America coming from New Jersey in 1916. Adults feed voraciously on the leaves and flowers of a wide range of plant species and are considered serious pests. Larvae feed below ground on plant roots. A distinctive and familiar species which leaves raged holes along the edges of the leaves of garden plants.
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Northern Masked Chafer Cyclocephala borealis
One of a number of rather similar, small, chestnut-colored chafers that come to light at night in good numbers. Larvae feed on a variety of plant roots and are often considered horticultural or agricultural pests.
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Eastern Hercules Beetle Dynastes tityus
An impressive beetle and one of our largest insects, females are smaller but the horned males can grow to well over two inches long. A woodland species, the adults sometimes come to light and can be quite startling, but are harmless to us. Larvae feed on decaying heartwood of trees and take two years to mature.
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Green June Beetle Cotinis nitida
A colorful and attractive species that inhabits clearings in wooded areas, especially in the north of the county. A little larger than a bumblebee and with a loud buzz from the wings in flight, these insects are hard to miss as they buzz around the landscape. Insects vary a lot in the amount of green and brown coloring.
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Bumble Flower Scarab Euphoria inda
A common summer flower beetle which is most often found on sunny days, feeding at flowers in open meadows. The color and overall hairiness - together with their behavior - give the beetles a passing resemblance to bumble bees.
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Emerald Flower Scarab Trichiotinus lunulatus
A common summer flower beetle which is most often found on sunny days, feeding at flowers in open meadows. The brilliant, metallic green overall color (including the legs) is distinctive.
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Delta Flower Scarab Trigonopeltastes delta
This wasp-mimic is uncommon but may be found by searching the flower heads of Wild Carrot during hot summer days. The bright yellow triangle on the thorax is diagnostic.
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