Characters for Identifying Common Families of Coleoptera POLYPHAGA, PART 2 [Cleroidea, Cucujoidea, Tenebrionoidea] [Note: 5-5-5, 5-5-4, etc. = number of tarsal segments on fore-, mid-, and hind legs, respectively] Cleroidea Cleridae - Checkered Beetles. Characteristics - Body elongate, narrow, with long, erect pubescence. Pronotum narrow, cylindrical; often marked with red, orange, yellow, or blue. Antennae frequently clubbed, sometimes threadlike. 5-5-5. Photos: Trichodes nutalli, Minnesota, Enocleris nigripes, Minnesota, and E. sphegeus, Idaho. Biology: Adults feed on adult bark beetles, while larvae feed on eggs, larvae, and adults of bark and long horned beetles in their galleries. These beetles are important in controlling populations of these wood boring pests. One species, the Red-legged Ham Beetle is a pest on ham, cheese, and other dried animal products; it also feeds on dermestid larvae. Melyridae - Soft-winged Flower Beetles. Characteristics - Elytra soft, loosely covering abdomen and widest toward rear of insect. Black, blue, or green, often with red, yellow or orange markings; often covered with erect, stiff hairs. Antennae sawtoothed or threadlike. 5-5-5. Photos: Males of Collops bipunctatus and C. quadrimaculatus, Minnesota, have the base of the antennae modified to grasp the female's antennae during mating. Biology: These beetles are found on flowers where they feed on pollen or prey on other insects visiting flowers; larvae are predaceous and can be found under bark. !1 Cucujoidea Nitidulidae - Sap Beetles. Characteristics - Relatively small (1.2-12 mm.), variable in shape but frequently broadly oval, sometimes with last few abdominal segments exposed. Color usually brown or black, often marked with yellow or red. Antennal club with abrupt, 3-segmented apex. Front coxae transverse. 5-5-5 or 4-4-4. Biology: Sap beetles feed on sap and rotting fruit, but are also found on flowers and carcasses. Some species are vectors of oak wilt fungus, including Glischrochilus fasciatus, in Minnesota. Other species are attracted to sweet corn damaged by the corn earworm. Includes also the hive beetle, found in bee hives. Photos: Glischrochilus fasciatus and Cryptarcha ampla occur in Minnesota. Cucujidae - Flat Bark Beetle Characteristics - Very flat, bright red or reddish brown. 5-5-5, or apparently 5-5-4. Photo: Cucujus clavipes, a striking flat bark beetle found in Minnesota, under bark of dead ash and poplar. Biology: Most found under bark of freshly cut logs, predaceous on mites and insects under the bark. Silvanidae - Saw-toothed Grain Beetles and relatives. Characteristics - Somewhat difficulty to characterize. head narrow, body somewhat flattened, pronotum with lateral serrations. 5-5-5, or apparently 5-5-4. Photo: the saw-toothed grain beetle, Oryzaephilus surinamensis, feeds on stored food products. Biology: Most are scavengers. !2 Languriidae - Lizard Beetles. Characteristics - Hard bodied with distinctive shape -- elongate slender and parallel-sided. Color shining black or blue-black. Pronotum (usually) reddish, orange or yellow (and also sometimes head and part of elytra). Antennae with 4-segmented club. 5-5-5. Photos: the Clover Stem Borer, Languria mozardi, and the colorful L. trifasciata, both found in Minnesota. Biology: Larvae of the former tunnel in the stems of red clover and alfalfa and are minor pests of these forage crops. Adults feed on pollen of goldenrod, ragweed and other plants, also leaves. Erotylidae - Pleasing Fungus Beetles. Characteristics - Small to medium sized, elongate or oval, black and shiny, often with red, orange or yellow markings; body without pubescence. 3-segmented antennal club. Front coxae rounded. 5-5-5. Photos: Triplax, including T. flavicollis from Minnesota are common and are often found on soft bracket fungi. Cypherotylus californicus, a specimen from Colorado. Biology: Adults and larvae on shelf fungus and other fungi of dead trees, logs, stumps !3 Coccinellidae - Ladybird Beetles, Ladybugs. Characteristics - Oval or nearly spherical in shape and convex dorsally. Color yellow, orange, red, or black (frequently with contrasting spots or markings). Head partly or totally concealed by pronotum. Antennae short and with 3-6 segmented club. Tarsi “apparently” 3-3-3 (actually 4-4-4). Photos: two species of Coleomegilla, C. vittegera and C. fuscilabris, the striped and spotted lady beetles, both feed on aphids. Coccinella transversoguttata from Minnesota. Biology: These are common and beneficial insects for the most part. Adults and larvae of most species feed on aphids, scales, and other soft bodied insects; however, in recent years some introduced species have become problematic. Imported species used for biocontrol on scale and other Sternorrhyncha. Overwinter as adults in large aggregations, under leaves, debris. Asian Lady Beetle, Harmonia axyridis a “pest” in houses here in Minnesota. Fly to buildings in search of overwintering sites and end up indoors. Once inside they crawl about on windows, walls, attics, etc., often emitting a noxious odor and yellowish staining fluid before dying. Some concern on the effect of introduced species on native ladybugs. Larvae, covered with minute tubercles, spines, usually spotted or banded with bright colors, “alligator bugs.” Only two species are phytophagous, pests on squash and beans. Endomychidae - Handsome Fungus Beetles. Characteristics - Rather oval in shape; forward angles of pronotum prolonged. Shining black or brown in color, often with red or orange markings. Antennal club 3-segmented. Tarsi “apparently” 3-3-3 (actually 4-4-4). Photos: two common handsome fungus beetles, Aphorista vittata (specimens for Ohio) and Endomychus biguttatus (Minnesota). Biology: Larvae feed on fungus and mold in rotting logs, fungi, decaying fruit, under bark, a few on flowers. Adults are found in fungi, decaying wood, and rotting fruit. !4 Tenebrionoidea Tenebrionidae - Darkling Beetles. Characteristics - Antennae 11 segmented and threadlike, beadlike, or slightly clubbed. Eyes notched by a projecting shelf, with antenna arising from below. 5-5-4. Photos: Alobates pennsylvanicus and detail of head showing shelf and antennal insertion. Bolitotherus vittata, Diaperis maculata, and Tribolium confusum. Biology: Large, diverse group. In arid regions take over ecological niche occupied by Carabidae in more verdant areas, common under stones, debris, loose bark. Most phytophagous, some as stored grain pests (larvae “mealworms”). Eleodes assumes amusing form when trying to escape: elevates tip of abdomen at 45° and appears standing on head as running - emits reddish-black foul fluid as defense. Tenebrionidae, Alleculinae - Comb-clawed Beetles. Characteristics - The only distinctive feature of comb-clawed beetles is the serrate tarsal claws, otherwise adults resemble tenebrionids and a number of other families. 5-5-4. Photos: Capnochroa fuliginosa. Biology: Adults feed on pollen, larvae feed on decaying plant material and are found in leaf litter, rottten wood, under bark, etc. !5 Zopheridae - Ironclad Beetles. Characteristics - Lack hind wings, and with elytra fused, very hard bodied, difficult to pin. 5-5-4. Photo: Zopherus haldemani. Biology: Little know, some associated with shelf fungi. Pyrochroidae - Fire Colored Beetles. Characteristics - Shape and color distinctive -- elongate; elytra parallel-sided or (frequently) widened poseriorly and black. Pronotum (and often head) reddish or yellowish. Antennae serrate, pectinate, or almost plumose. 5-5-4. Photo: Dendroides sp. Biology: Larvae live under bark of dead trees. Adults of flowers and foliage, also under bark. Melandryidae - False darkling beetles. Characteristics - Very difficult to characterize, but there are often two dents at the base of the pronotum and the hind basitarsus is longer than any of the other segments. 5-5-4. Photos: Two examples from Minnesota, Dircea liturata and Melandria striata. Biology: found under bark and logs. Mordellidae - Tumbling flower beetles. Characteristics - humpbacked and wedge-shaped (head bent down and abdomen pointed); antennae short (threadlike, serrate, or clubbed). 5-5-4. Photos: Two species of tumbling flower beetles from Minnesota, Gilpa octopunctata and Mordella atrata. Biology: Common on flowers, especially composites and umbelliferae; feed on pollen. Agile, quick to escape, “tumble”. Larvae burrow in plant stems and rotting logs !6 Rhipiphoridae - Wedge-shaped Beetles. Characteristics - Humpbacked and wedge- shaped (like Mordellidae), but abdomen blunt; antennae pectinate or serrate; forewing often short with hindwing projecting. 5-5-4. Photos: Rhipiphorus fasciatus a Minnesota species and detail of the male's feathery antennae. Biology: Some females wingless, larviform, otherwise resemble mordellids. Adults short lived, often associated with goldenrod flowers. All larvae parasites of bees (some in underground burrows) and wasps; 1st larval instars active triungulins, well-developed legs, attaches to bee as it visits flower, carried to nest, becomes internal parasite on bee egg, feeds internally on larva when hatches; overwinters in this stage, not completing 1st instar until following spring. Then leaves host body and spends 2nd-6th instars feeding on host from outside as external parasite; host alive until last 2 days of feeding; pupates; adults free living. Meloidae - Blister Beetles. Characteristics - Body soft, often leathery; shape usually distinctive -- head broad and wider than thorax; elytra elongate and wider than thorax with "rolled" edges;