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Home , Cassidini, Chrysomeloidea, Compsocerus violaceus, Cryptocephalinae, Desmocerus palliatus, Macrodontia (genus)

Characters for Identifying Common Families of Coleoptera

POLYPHAGA, PART 3 [, Curculionoidea]

Chrysomeloidea

Cerambycidae -Long-horned . Characteristics - Antennae long, often very long, at least extending beyond base of pronotum (except short in ); eyes usually notched, with base of antenna in notch; tarsi “apparently” 4-4-4 (that is, 3rd tarsal segment expanded, concealing true, but very small, 4th segment) (except 5-5-5 in Parandrinae). Biology: Large ; > 1000 U.S. All phytophagous, most adults feed on flowers, larvae wood boring - round head borers. Many species destructive to trees, usually weakened or dying, or fresh cut logs. Many stridulate, may hear squeaking sound when handled. Females lay eggs in crevices

Cerambycidae, Parandrinae - Aberrant Long-horned Beetles. Characteristics - see key below; also, aberrant long-horned beetles resemble stag beetles more than other longhorns. Photos: glabra from Costa Rica. Biology: Adults are active at night, when females oviposit on exposed tree trunks, they can be “hunted” with flashlights; extensive borings by larvae cause windfalls.

Cerambycidae, - Tooth-necked Long-horned Beetles. Characteristics - see key below. Photos: pocularis from Missisippi and a large tropical species from , cervicornis. Biology: Larval prionines feed on roots of trees and their borings can cause considerable damage. They move from root to root through the ground.

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Cerambycidae, Lamiinae - Flat-faced Long-horned Beetles. Characteristics - see key below; also notice the vertical “flat face” and the pointed maxillary palps and body with hairs forming distinctive color patterns. Photos: The sawyer, Monochamus scutellatus (specimen from Michigan) is a serious best of dying and felled pine and other conifers. Plectrodera scalator, the cottonwood borer. from Minnesota, a species that feeds on milkweed. Acrocinus longimanus, the Harlequin , a large Neotropical species. Biology: Very varied, feeding as larvae in a wide variety of trees, shrubs, and herbaceous plants; many are pests.

Cerambycidae, - Flower Long-horned Beetles. Characteristics - see key below; also notice the bell-shaped pronutum, the “broad’shouldered” appearance of the elytra, and the last maxillary palp segment is blunt at the tip, not pointed. Photos: Cosmosalia chrysocoma, palliatus, and velutinus. Biology: Adults are usually found feeding on flowers and many have narrow fore-bodies for getting to the pollen and floral nectaries; they are good fliers. Larvae bore in trees and other woody plants.

2 Cerambycidae, - Round Necked Long-horned Beetles Characteristics - see key below; also the pronotum is rounded and the 5th maxillary palp segment is pointed. Photos: robiniae, the locust borer. Two striking Brazilian species, violaceus and Monochroma aurosum. Biology: This is the largest subfamily and include some very striking beetles. Larvae feed in a wide variety of woody plants.

Key to Selected Subfamilies of Cerambycidae (from Tripplehorn and Johnson)

1. Tarsi 5-5-5; antennae short, usually not reaching base of pronotum ...... Parandrinae Tarsi “apparently” 4-4-4 (that is, 3rd tarsal segment expanded, concealing true 4th segment); antennae long to very long, extending beyond base of pronotum ...... 2

2. Head vertical or retracted; genal margin (“cheeks”) always directed posteriorly ...... Lamiinae Head inclined anteriorly or subvertical; genal margin never directed posteriorly ...... 3

3. Pronotum with raised, often toothed, lateral margins; large brown species .....Prioninae Pronotum without raised lateral margins; size and color variable ...... 4

4. Stridulatory plate of mesonotum large, undivided ...... Cerambycinae Stridulatory plate of mesonotum divided by median longitudinal stripe; pronotum bell- shaped ...... Lepturinae

3 Chrysomelidae - Characteristics - Diverse family, difficult to characterize, generally with filiform antennae, but not nearly as long as in Cerambycidae and with “apparently” 4-4-4 tarsal formula (as in long-horns, 3rd tarsal segment expanded, concealing true 4th segment); eyes usually not notched. Often more easily identifiable by subfamily. Biology:Large family (1700 spp., 195 genera in N Amer alone; 38,000 and 2500 respectively in the world), closely related to Cerambycidae. Often very brightly colored, metallic, diverse shapes, but generally oval. All phytophagous on all plant parts, serious pests of cultivated plants, including vegetables, - “,” probably best known, asparagus, cucumbers, fruits, grapes, & ornamentals, etc.

Chrysomelidae, Bruchinae - Seed beetles. Characteristics - shape distinctive, body egg-shaped, eyes notched, short, broad “beak”, head concealed from above, hind femur enlarged, often with teeth on inner margin. Note: Once a separate family, Burchidae, now considered a subfamily of chrysomelids. Photos: The cosmopolitan bean , Acanthoscelides obtectus, is a serious pest of stored beans and peas (example of damage). Biology: larvae feed in seeds of various plants, especially the bean family, Leguminoceae. Adults can be found on flowers.

Chrysomelidae, “Chlamisinae” - Warty Leaf Beetles. Characteristics - Distinctive - with corse warts and fine striations, often resemble caterpillar frass; elytral suture serrate. Photos: eubati. Biology: Larvae live in protective cases of frass and feed as herbivores on leaves.

Chrysomelidae, - Cylindrical Leaf Beetles. Characteristics - head is disklike and can be withdrawn into pronotum. Photos: leucomelas. Biology: Adults and larvae occur on foliage, fruit, or flowers. Many have distinctive color patterns.

4 Chrysomelidae, Chrysomelinae - Broad-bodied Leaf Beetles. Characteristics - Most are oval to nearly circular and highly convex body shape,but some are more elongate-robust; the 3rd tarsal segment is not as deeply bilobed as in some subfamilies. Photos: Caligrapha scalaris and Leptinotarsa decimlineata, dorsal and frontal views. Biology: Larvae and adults feed on foliage and flowers, includes the Colorado Potato beetles and other bests.

Chrysomelidae, Donaciinae - Long-horned or Aquatic Leaf Beetles Characteristics - Confused with long-horns as the antennae are long, but pronotum lacks lateral margins; hind legs enlarged; dark, metallic bronze or green in color. Photos: Donacia piscutrix. Biology: larvae are aquatic and feed in stems of submerged and emergent aquatic plants, especially waterlilies in Minnesota. The larvae have terminal spiracles tipped with a spine to pierce the plant tissue to extract oxygen. Adults have a coating of fine hairs on the ventral surface to trap air used when the female crawls under water to lay eggs; adults are very common on the surface of waterlilies in the summer and are fast, agile fliers.

Chrysomelidae, Galerucinae - Skeletonizing Leaf Beetles. Characteristics - Head clearly visible from above, pronotum slightly narrower at base than elytra and with a distinct lateral ridge; elytra broadest at rear. Photos: Diabrotica longicornis, Corn Root Worm, and Diabrotica undecimpunctata, . Biology: Includes some major agricultural pests, such as the Corn Root Worm, that feeds on corn silk and leaves as adults and roots as larvae. Others feed as adults and larvae on leaves, often “skeletonizing” the leaf.

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Chrysomelidae, “Alticinae” - Flea Beetles. Characteristics - hind femora enlarged, used for jumping. Photos: Altica bimarginata. Biology: Adults feed on leaves, often leaving tiny, shot-hole damage; larvae feed on roots. Includes many pestiferous species, e.g. Corn Flea Beetle, Sweet Potato Flea Beetle, Grape Flea Beetle. Because they feed on foliage and roots, many species are used in biological control of weeds in this and other subfamilies of leaf beetles.

Chrysomelidae, “Hispinae" - Leaf-mining Leaf Beetles. Characteristics - Head points backward, mouthparts very small; elytra with distinct ridges and rows of punctures, Photos: Baliosus nervosus. Biology: Larvae mine leaves and can cause defoliation, but the tree is generally not harmed.

Chrysomelidae, “” - Tortoise Beetles. Characteristics - Shape very distinctive, circular or oval, with sides of body expanded laterally, covering head and appendages form above. Often brilliant metallic/iridescent in color. Photos: guttata, Acromis spiniflex, and Agenyea caedamadens. Biology: larvae and adults feed on foliage, commonly of the morning glory family. Larvae are flat and spiny, with a forked appendage at the end of the body to which they attach frass, debris, etc. They flick this ammunition at predators. Some females engage in parental care.

6 NOTE: Chrysomelid sub-familial classification has been revised over the last several years. For the subfamilies above, the new classification is as follows (note: there are several other subfamilies, not on our list).

OLD NEW Chrysomelidae Chrysomelidae Donaciinae Donaciinae Chlamisinae Cryptocephalinae, Fulcidacini Cryptocephalinae Cryptocephalinae Chrysomelinae Chrysomelinae Galerucinae Galerucinae Alticinae Galerucinae, Alticini Hispinae Cassidinae, Hispini Cassidinae Cassidinae, Bruchidae Bruchinae

Curculionoidea

Brentidae - Primitive , Straight Snouted Weevils. Characteristics - Shape distinctive, tarsi usually “apparently” 4-4-4; elongate and parallel-sided body. Head with very long or short straight beak; antennae beadlike or threadlike.Photos: Arrhenodes minutus, the oak timberworm, a native Minnesota brentid. Brentus anchorago, a tropical species found in southern Florida. A Venezuelan species and detail of the beak. Biology: Males with strong mandibles fight with other males for females; guard her while she bores hole to lay eggs, sometimes helping her extract her mouthparts if they become wedged, may take a day to complete task. If another male comes along and 1st male loses fight, new male will take his place assisting female; loser is not injured, just weaker and gives up. Adults under loose bark of dead trees; some larvae attack living trees

7 - Weevils, Snout Beetles. Characteristics - Tarsi usually “apparently” 4-4-4. Usually with a well developed, curved snout.; antennae clubbed and almost always elbowed (geniculate) and often recessed into groove along snout; palps small and often concealed; labrum absent. Photos: Examples of exotic weevils from Cameroon, , French Guiana, Peru, and three species from Venezuela. Biology: Very diverse, 44,000 species. Many serious pest of plants, feed on all parts: boll weevil, strawberry weevils, plum curculio - all well known, economically important pests. Larvae are legless, usually feed inside plant tissues, adults usually bore into plant parts from the exterior. Found everywhere, including aquatic species. Some associated with ant nests. When disturbed will draw in legs, antennae & fall to ground and remain motionless. Some flightless spp. (Brachyderinae) - elytra fused, hind wings vestigial. Family contains many subfamilies, including the important Scolytinae, formerly considered a separate family.

8 Curculionidae, Scolytinae - Bark and Engraver Beetles. Characteristics - Tarsi “apparently” 4-4-4; small brown or black, cylindrical, elongate beetles; frequently with head partly or wholly concealed and thorax relatively elongate compared to elytra; tips of elytra often squarred off; antennae elbowed and clubbed; tarsi short. Photos: Ips pini. Biology: Bark beetles - greater impact on timber producing forests than any other group of . Elm bark beetle is a familiar pest in MN, as elsewhere; Ips pine beetles very significant pests. Due to large numbers infesting at once, large stands of trees are often affected. Feed on phloem tissue (cellular part of bark just under epidermis), may deeply score sapwood; in living and dying trees; death of living tree brought about by fungus introduced by adults and spread by larvae. Fungus clogs water transport tissues and prevents sap from flowing into beetle galleries. Beetles overcome tree defenses by sheer numbers - thousands; attracted by odor of resin and chemical signals from previous colonists. As females construct galleries, males follow behind removing dust, shoving it out entry hole. She lays her eggs, in notches along sides of gallery tunnels. Larvae eat their way along through phloem, moving away from gallery; frass filled mines form characteristic patterns - each species has characteristic pattern made by adults and larvae. Pupate at ends of mines, exit through hole they bore through bark; infested tree appears peppered with holes

Ambrosia beetles - Bore into wood of living or freshly killed trees with high moisture content; do not eat wood, but feed on ambrosial form of fungus which they cultivate; each species on specific fungus; fungus stains wood and decreases value; entire shiploads may be refused at foreign ports if signs of these beetles present. Both adults and larvae live in galleries, usually female adults feed young, until pupae, keeping supplied with fungus and keeping niche clean and free of frass. Females emerge, fly to another tree and spread fungus to new host; carry fungus in special area at base of elytra. Some show haplodiploid parthenogenesis. More diverse in tropics. Not very host specific.

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