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Home , Amphicerus bicaudatus, Aphodius foetens, Aphonus, Bostrichoidea, Buprestis fasciata, Buprestoidea

Characters for Identifying Common Families of Coleoptera

POLYPHAGA, PART 1 [, , , , , Dryopoidea, , Cantharoidea, Dermestoidea, ]

[Note: 5-5-5, 5-5-4, etc. = number of tarsal segments on fore-, mid-, and hind legs, respectively]

Scirtoidea

Scirtidae (=Helodidae) - Marsh . Characteristics - Small, oval; head usually hidden from above; ventrally the pronotum has a groove behind the forecoxa that the foreleg femur fits into. 5-5-5, 4th tarsal segment with small, but distinct paired lobes, densely hairy below. Biology: aquatic as larvae, semi-aquatic as adults, associated with standing water of marshes, swamps, tree holes, etc.; often very abundant. Larvae are unusual among Holometabola in having long, multisegmented antennae; feed on micro-organisms.

Hydrophiloidea

Hydrophilidae - Water Scavenger Beetles. Characteristics - Antennae short and with 3-5 segmented clubbed, sometimes hidden; maxillary palps long, usually longer than antennae and easily confused with antennae by novice; body oval and convex; often with hind legs flattened and fringed with hairs (aquatic species), and with backward- projecting spine between legs on venter of thorax. 5-5-5 or 5-4-4. Photos: Tropisternus sp., an aquatic water scavenger , and ventral view showing the metasternal spine, clubbed , and long maxillary palp. Sphaeridium lunatum, an introduced terrestrial species now found in Minnesota,without aquatic modifications, but with clubbed antennae. Biology: 2nd largest of aquatic beetles Adults hydrophilids are omnivorous or scavengers. Larvae are predaceous, with large toothed mandibles, clearly visible from above. Most are aquatic in ponds, quiet streams, lay eggs in aquatic plants, larvae leave water and pupate in underground earthen cells. Some are terrestrial, especially found in dung

1 - Beetles. Characteristics - Small (10 mm or less), elytra short, exposing the tip of the abdomen (no more than 2 segments exposed), antennae short, elbowed, and clubbed, tibia usually wide and flattened, body often black and shiny; usually oval or elliptical in shape, but greatly flattened in some species. 5-5-5 or 5-5-4. Photos: Hister arcuatus, Minnesota, profusus and aequatic. Biology: Histerids are found in decaying organic matter, dung, fungi, carrion, under bark, in ant and termite nests, or galleries of wood-boring beetles. They are predators.

Staphylinoidea

Staphylinidae - Rove Beetles. Characteristics - Shape distinctive: elongate, slender, and parallel sided, elytra short (equal to or only slightly longer than the pronotum in length), much of the abdomen (5-6 segments) exposed dorsally; antennae thread-like or clubbed, in front of eyes instead of between them. Usually 5-5-5. Photos: Ortholestes cingulatus and Bledius rotundicollis. Biology: Rove beetles comprise one of the two largest families of beetles, they are dominant in northern forests. Adults are active, run, fly fast, among most proficient flyers of all beetles; may run backwards, raise up tip abdomen as scorpion in defense. Most are predaceous, but often associated with decaying organic matter, often dung, carrion; some in bird, mammal, ant, termite nests; some parasitic on other , others ectoparasites on rodents

Staphylinidae, - Short-winged Mold Beetles. Characteristics - Resemble staphylinids in having short elytra, but abdomen is rounded and wider at middle, head and thorax narrower; usually orange or reddish brown. Photo: Batrisodes striatus. Biology: These beetles are found in rotting logs, under stones, moss; ant, termite, & mammal nests; predators, but ants “milk” some for nutritious secretion

2 Staphylinidae, - Shining Fungus Beetles. Characteristics - Body shape distinctive, broadest in middle; apex of abdomen pointed and exposed; antenna with a gradual or abrupt 2-6 segmented club; usually shiny, black or brown beetles. Photo: quadriguttatus. Biology: Scaphidiines are associated with fungus.

Silphidae - Carrion Beetles. Characteristics - Elytra slightly to moderately short, exposing the tip of the abdomen dorsally, elytra usually flattened and leathery rather than hard and horny, often only loosely cover body, elytra tend to widen posteriorly, antennae clubbed, with last 2-3 segments pubescent. Generally rather large beetles with flattened shape and soft body. Frequently black or blackish in color with yellow, orange, or red markings. 5-5-5. Photos: Silpha americana, Oiceoptoma noveboracense, Heterosilpha ramosa, surinamensis, and the American burying beetle, Nicrophorus americanus (detail of antenna), listed in some states as an endangered species. Biology: Associated with carrion; others predatory or phytophagous. Mated pairs may move large carcass (rat sized) several feet. Adults excavate hole beneath carrion, lower carcass in and shape it into a bolus, lay eggs, cover. Extended parental care; adults regurgitate carrion for newly hatched larvae; stridulate to attract larvae; clean bolus of fungi and secrete fluids to keep it from rotting.

Ptiliidae - Feather-winged Beetles. Characteristics - Very small beetles (0.25-1.0 mm.) that feed on fungus spores. Antennae clubbed, each segment with whorl of long hair.; hindwing with fringe of long hair; body oval, often pubescent. Some of these beetles are smaller than many protozoa! 5-5-5. Photos: a feather winged beetle and detail of its antenna. Biology: They are associated with leaf litter, dung, rotting wood, where they feed on fungus.

3 Scarabaeoidea

Lucanidae - Stag Beetles. Characteristics - Black to red-brown in color, body wide and parallel-sided, pronotum separated from the elytra, pronotum without a median longitudinal groove, antennae elbowed with last 3-4 segments forming a club that cannot be held tightly together, mandibles may be very large in males. 5-5-5. Photos: Pseudolucanus capreolus (detail of head showing antennae and mandibles) and Platycerus depressus, two from Minnesota. Examples of exotic species: Prosopocoilus giraffa from Java and Odontolabis cuvera from India. Biology: Lucanid males will rear up in defense with open mandibles, & will fight other males for females. Most found in wooded areas, some on sandy beaches. Adults feed on sap, honeydew; larvae feed on decaying wood.

Passalidae - Bess Bugs, Betsy Beetles. Characteristics - Large (30-40 mm) and shiny black or brown in color, body wide and parallel-sided, pronotum distincly separated from the elytra, pronotum with a single median longitudinal groove, head with a small median horn, last three segments of antennae form a club, but cannot be held tightly together. 5-5-5. Photos: disjunctus, goes by the name of bess bug, betsy beetle, or horned passalus. Lateral view of head showing horn. Biology: Larvae and adults live in logs in loosely organized colonies; galleries large, frass indicates presence. Feed on microorganisms; new larvae will not mature unless these organisms present, adults help feed larvae by pre-chewing wood. Adults stridulate (rub wings against dorsum abdomen) to communicate and if disturbed; larvae also stridulate using hind leg.

Trogidae - Hide Beetles. Characteristics - Similar to scarabs, with lamellate antennae, but body not shiny and with distinct ridges and tubercles. 5-5-5. Photos: Omorgus punctatus, from Minnesota. Biology: These beetles are scavengers attracted to old dry carcasses, feed on hide, feathers, hair, dried tissues on bones, representing last stage in succession of insects living in animal carcasses; others occur in owl pellets, bird nests, or mammal burrows.

4 - Scarab Beetles. Characteristics - Robust, heavy-bodied, convex beetles, antennae lamellate, with last 3-7 segments composed of flattened lobes that can be held tightly together, front tibia widened with the outer edges toothed. Very diverse family; size and color variable. 5-5-5.

Scarabaeinae (=Coprinae) - Dung beetles. Characteristics - see key below. Photos: Copris tullus, Minnesota, and Phaeneus carnifer, Illinois. A tumblebug, laevis, Minnesota. Biology: Adults of this subfamily provide dung balls to the larvae for food. The adults chew off piece of dung, work into a ball, sometimes may roll a long distance, usually in pairs, pushing-pulling, rolling with hind legs, bury in , eggs laid in ball, larvae provisioned/protected. Egyptian mythology: dung ball represented earth and its rotation

Aphodiinae - Characteristics - see key below. Photos: foetens and Ataenius strigatus, Minnesota. Biology: These scarabs feed in dung, especially cow dung, or rich organic matter.

Melolonthinae - June beetles and chafers. Characteristics - see key below. Photos: A June beetle, Phyllophaga nitida, from Minnesota, and the characteristic bifid tarsal claw of melolonthines. This is a large in the US with almost 200 eastern US spp., their “white grubs” important turf pests; 2-3 yr life cycle. Serica sericea, a small Minnesota melolonthine. Dichelonyx albicollis, Minnesota, adults feed on jack pine leaves, larvae feed on tree . Polyphylla decemlineata, South Dakota, larvae feed on roots of trees and shrubs and can be destructive. A chafer, Macrodactylus sp., Minnesota, adults can be destructive defoliators.

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BiologyLarvae of melolonthine scarabs live in the soil and feed on roots or humus, adults usually feed on leaves, flowers, and fruits- damage ornamentals, grasses, grains, , grapes, peaches, potatoes.

Rutelinae - Shining leaf chafers. Characteristics - see key below. Photos: The introduced Japanese beetle, Popillia japonica, is a serious defoliator of many plants. Pelidnota punctata, Minnesota, adults feed on leaves and fruits of grapes. lanigera, Minnesota, are found on catalpa trees. Anomala binotata, Minnesota, is of little economic importance. Chrysophora chrysochlora is a striking species from Ecuador. The jewel beetle of the genus Chrysina (formerly in Plusiotus) are favorites of collectors: C. batesi, Costa Rica, C. beyeri, Costa Rica, C. boucardi, Costa Rica, and C. gloriosa, Texas. Unequal tarsal claw of Strigoderma arboricola showing the typical ruteline character. Biology: adults feed on leaves and fruit; the larvae feed on roots.

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Dynastinae - Hercules, Rhinoceros and Elephant Beetles. Characteristics - see key below. Photos: The Eastern Hercules beetle, tityus, male and female. Aphonus densicaudus, Minnesota, The Hercules beetle, Dynastes hercules, Colombia. An , elaphus, Costa Rica. Other examples of large, exotic dynastines, Enema pan, Colombia, Eupatorus gracillicornis, Thailand, Golofa eacus, Venezuela, and Chalcosoma atlas, Africa. Biology: larvae usually feed in rotting logs and stumps; some are pests of crops.

7 Cetoniinae - Flower Beetles. Characteristics - see key below. Photos & Biology: Some examples of Minnesota flower beetles: inda, the bumble flower beetle, flies and sounds like a bumble bee; Euphoria limbalis, a beautiful metallic green species, in this genus the elytra are not extended in flight, but keep folded over back and extend hind wings through shallow emarginations at sides of elytra; piger adults occur on flowers, larvae are found in decaying hardwoods; adult hermit flower beetles, Osmoderma eremicola, are malodorous and found under bark of dead trees, larvae feed in decaying wood. Adult green June beetles, Cotinus nitida, feed on grapes, other fruits, and young corn; larvae can be serious pests in turf. The goliath beetles, Goliathini, of Africa contain some of the largest insects: Goliathus goliatus, G. orientalis, G. cacicus, G. regius, Megalorrhina harrisi, Mecynorrhina torquata, Chelorrhina polyphemus, Dicranorrhina derbyana, and D. micans. Another Cetoniinae genus, , held captive in ant nests and ants gather nutritive fluid they secrete, clinging to beetle thorax, gnawing at glandular areas on metathorax.

8 Key to the Subfamilies of Scarabaeidae (from Tripplehorn and Johnson)

1. Last segment of abdomen covered by elytra ...... Aphodiinae Last segment of abdomen exposed ...... 2

2. Where antennae insert on head visible from above, clypeus with sides constricted ...... Cetoniinae Where antennae insert on head not visible from above, clypeus with sides not constricted ...... 3

3. Ventral abdominal segments narrowed in the middle; length of ventral abdominal segments shorter than length of metasternum ...... Scarabaeinae Ventral abdominal segments not narrowed in the middle; length of ventral abdominal segments longer than length of metasternum ...... 4

4. Tarsal claws of middle and hind legs unequal in length and independently movable; 5th tarsal segment with long, ventral groove down the middle ...... Tarsal claws of middle and hind legs equal in length and not independently movable; 5th tarsal segment without long, ventral groove down the middle, but with 2 parallel grooves on either side of middle ...... 5

5. Tarsal claws of middle and hind legs simple, not cleft ...... Tarsal claws of middle and hind legs cleft ......

Geotrupidae - Earth Boring Dung Beetles. Characteristics - Similar to scarabs but have 11 segmented antennae (instead of of 10 or fewer in scarabs) and with 3 segmented club (segments circular or oval); stout, oval bodied. 5-5-5. Photos: lazarus, Minnesota, Bolbocerosoma bruneri, Minnesota, and opacus, Missouri. Biology: Adults of these dung beetles live in burrows below carcasses or dung sources, they rarely leave the burrow.

9 Buprestoidea

Buprestidae - Metallic Wood Boring Beetles. Characteristics - Body with characteristic bullet shape, cuticle with a metallic sheen (especially ventrally), antennae short, saw-toothed or thread-like, elytra come together. 5-5-5. Photos: Acmaeodera pulchella adults are found on black-eyed susan flowers in the summer, in the southern US, larvae of this species bore into bald cypress; fasciata, a beautiful metallic green species, and virginiensis, whose larvae bore in the heartwood of injured, dead, or dying pine. A large Neotropical species, gigantea, from Ecuador; the larvae bore in ceiba and balsa wood, the elytra are used in necklaces and other ornaments by South American indigenous people. Biology: Larvae tunnel in dead, dying trees, logs; others in sap wood of living trees, or recently cut wood; also mine foliage,stems, fruit trees, girdle twigs; some make galls. Create large winding galleries, filled with frass; “flat-headed borers” pupation in galleries. Emerald ash borer!

Dryopoidea

Heteroceridae - Variegated Mud-loving Beetles Characteristics - Distinctive shape - mandibles of male extended forward. Tibiae flattened and spined on outer margin (fossorial). 4-4-4. Elytra often with undulating yellowish bands or spots. Antennae short, serrate. Photos: Heterocerus sp., from Minnesota. Biology: Adults and larvae burrow in mud or sand burrows along streams or lakes, usually marked by little “chimneys”.

Elmidae - Riffle Beetle. Characteristics - Body oval and dark in color. Head mostly concealed from above. Legs long; claws large. Antennae short to moderate in length, clubbed or threadlike. 5-5-5. Photos: glabratus, Minnesota. Biology: Adults, of most species, are aquatic and are found in cool, well oxygenated streams. The adults breath via a "plastron gill." Larvae are aquatic. The long legs and claws help the adults grip submerged substrate.

10 Elateroidea

Elateridae - Click Beetles. Characteristics - Body elongate with elytra narrowing posteriorly, posterior corners of pronotum pointed, backward-pointing spine on venter, originating between the front pair of legs and fitting into a groove between middle pair of legs, antennae usually saw-toothed. 5-5-5. Photos: mellillus, Minnesota; the eyed , oculatus; and a species of from Venezuela with bioluminescent organs on the pronotum, producing stronger than . Biology: Adults phytophagous; larvae “wireworms”, slender, hard-bodied, shiny, may be very destructive on newly planted seeds & roots of beans, cotton, potatoes, corn, cereals; some larvae predaceous on insects found in rotting logs; pupation in ground, rotting wood, under bark.

Cantharoidea

Phengodidae - Gloworms. Characteristics - Female larviform; male flat, soft-bodied; antennae plumose; HW extending beyond short FW and covering abdomen. 5-5-5. Photos: An adult male , sp., from Texas and detail of its head. Biology: Females are "larviform" and the larvae are luminescent; both occur in leaf litter or under bark and logs. Larvae are predaceous.

11 Cantharidae -Soldier Beetles. Characteristics - Body elongate and parallel-sided, head normally not concealed by pronotum when viewed dorsally, tip of abdomen same color as the rest of the abdomen (when viewed ventrally), elytra leathery rather than hard and shell like, antennae usually thread-like, fourth tarsal segment modified into flattened lobes. 5-5-5. Photos & Biology: pennsylvanicus, a very common in Minnesota; adults are abundant on goldenrod and other similar flowers in the late summer and early fall where they feed on or small insects; larvae occur on damp ground and feed on soft-bodied insects.

Lycidae - Net-winged Beetles. Characteristics - Elytra leathery rather than hard and shell-like, elytra with pronounced longitudinal ridges that have a reticulate network of veins between them, elytra become wider posteriorly, not parallel- sided, elytra usually colored with red, black, orange, or a combination, majority of the head concealed by the pronotum when viewed dorsally, antennae flattened, either thread-like or saw-toothed. 5-5-5. Photos: Examples of three net-winged beetles from Minnesota: Calopteron terminale, C. reticulatum, and Dictyopterus aurora. Biology: Adults are active during the day on leaves and flowers, usually in shady places, they feed as predators or on decaying vegetation; larvae live under bark and are predators.

Lampyridae - Lightningbugs or Fireflies. Characteristics - Soft bodied, similar to cantharids, but head concealed from above by pronotum. Last 2-3 abdominal segments often luminous. Color usually brownish or blackish with yellow or orange. 5-5-5. Photos: A male lightningbug or , Photurus pennslyvanicus, from Minnesota and its head, showing the very large eyes. Biology: Adults of most species have light producing organs; larvae of all species are bioluminescent. Luminescent organs (most species, both sexes) on last 2-3 abdominal segments, yellow-green, produce ; ~100% efficient light. Species specific flashing; some species with predatory females, that use light producing organs to imitate flashes of other species and lure males to feed on them - aggressive . Some males flash individually to attract female, others flash in groups. Some females wingless, larviform, luminescent. Larvae predaceous, feed on insects, , most also luminescent, also known as “”.

12 Dermestoidea

Dermestidae - Dermestids. Characteristics - Elongate or oval body, often covered with scales or hair. Antennae short and clubbed and fitting into grooves below sides of pronotum. 5-5-5. Photos: The Larder Beetle, lardarius, is a cosmopolitan species found on dried meat products, cheese, hides, and furs (detail of its antenna, showing the abrupt club). simplex and other species in the genus Trogoderma are associated with plant and animal material, one species, the Khapra Beetle, T. granarium, is a very serious pest in stored grain and cereal products. Biology: Mostly scavengers on variety of plant and animal products: wool, silk, fur, rugs, leather, even upholstery, museum specimens, stored products, carrion; most damage by larvae; some are used to clean skeletons for study. Thylodrias contractus, "Odd beetle” with wingless, larviform female, and male with long filiform antennae - unusual shape and antennae compared to other dermestids.

Bostrichoidea

Anobiidae - Death-watch Beetles. Characteristics - Small to medium sized, usually brown or black body. Pronotum hoodlike, enclosing head and concealing it from above. Antennae (nearly always) with last 3 segments lengthened and expanded, often pectinate (comblike). Appendages often contractile; hind coxae grooved for reception of femora. 5-5-5. Photos: the Cigarette Beetle, serricorne (dorsal and lateral), which feeds on dried tobacco and other stored products. Trichoderma gibbosa larvae (detail of antenna) bore into twigs and wood. ruficornis is a very common eastern US species; larvae bore into hardwood, including furniture and structural lumber. Biology: Some adults make ticking sound by tapping mandibles on sides of tunnels as they bore into wood, audible to humans in quiet situations - funerals; superstitious people thought the noise is the sound of coming death. Some common, destructive pests: drugstore beetle, cigarette beetle, pest in drugstores on drugs, tobacco; museum specimens, household spices, especially paprika, chili powder, stored grain products. “Furniture beetle” on wood products, woodwork, and structurally on buildings.

13 - Branch-and-twig Corers: Characteristics - Body form distinctive -- cylindrical, parallel-sided. Head bent down and nearly concealed from above. Pronotum (usually) with rasplike teeth anteriorly. Antennae with loose, 3-4 segmented club. 5-5-5. Photos: bicaudatus from Minnesota and Apatides fortis from Texas. Biology: Bostrichid larvae bore into and damage living trees, dead twigs, branches, seasoned lumber and wood products, bamboo, and stored roots and grain; Western sp, declivis, adults bore into lead sheathing on telephone cable, do not eat it but enable moisture to enter and short circuit wires, “short circuit beetle”.

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