Barkgnawing And Checkered Beetles 165

and FW closely joined, margins of pronotum and FW broadly flattened. Tarsi 5-5-5, 1st segment very short. Antennae clubbed, the club segments often extended laterally. Black, brown, blue, or metallic green. 6-20 mm.

Adults and larvae of this small family normally live under bark, in fungi, and in dry vegetable matter One species is common in granaries, where larvae and adults feed on other insects or on damaged grain.

CHECKERED BEETLES Family Cleridae See also Pl. 5

Identification: Body elongate-narrow, with long erect pubescence.

Checkered Beetles

Pronotum narrower than FW, almost cylindrical. Head usually as wide as or wider than pronotum. Often marked with red, orange, yellow, or blue. Antennae variously clubbed or threadlike. 3-24 (mostly 3-10) mm.

Clerids are fairly common on trunks of dying or recently killed trees and on flowers and foliage. Most larvae and adults are predaceous on larvae of various wood-boring insects. Some species are beneficial in controlling bark beetles; they track down and devour bark beetle larvae in their burrows. Some adults and a few larvae are pollen feeders. One species, the Red-legged Ham Beetle, Necrobia rufipes (De Geer), is destructive to stored meats.

Superfamily Elateroidea

Prosternum often prolonged posteriorly into a lobe that fits into a depression in mesosternum. Abdomen usually 5-segmented.

Tarsi 5-5-5. Mostly moderate-sized. Most beetles in this group are plant feeders and some are important pests.

SANDALID BEETLES Family Sandalidae Identification: Elongate-robust. FW nearly parallel-sided. Pronotum tapers anteriorly. Antennae short, serrate, pectinate, or flabellate. Mandibles large, prominent. First 4 tarsal segments each with 2 lobes beneath. Brownish to black. 16-24 mm.

The 5 N. American species of sandalids are usually found around elm and ash trees in spring or fall. They are excellent fliers. Larvae are Darasites of cicada nymphs.

CEDAR BEETLES Family Rhipiceridae Not illus.

Identification: Elongate-oval, black, similar to Sandalidae but smaller (11-15 mm.), tarsal segments not lobed, mandibles small, and antennae serrate.

The single N. American species in this family, Zenoa picea (Beauvois), occurs from Florida to Texas, north to Iowa, Ohio, and Pennsylvania, where it is found under logs and bark. This insect is quite rare and little is known of the habits of either adults or larvae.

CLICK BEETLES Family Elateridae

Identification: Shape distinctive: body elongate-narrow, somewhat flattened, usually parallel-sided, and rounded at each end or FW rather pointed at tip; posterior corners of pronotum prolonged backward into sharp points. Prosternum with an elongate lobe extending posteriorly into a mesosternal depression (this feature, plus a loose articulation of the pro thorax, enables these beetles to "click"). Antennae usually serrate, sometimes threadlike or pectinate. Prosternum broadly lobed

CLICK AND CEROPHYTID BEETLES 167

anteriorly. Brown or black, sometimes lightly patterned. 3-45 mm.

Click beetles are named for their ability to click and jump. If one is turned onto its back, the head and prothorax are bent backward and then the body is suddenly straightened. This straightening produces an audible click and the beetle is propelled into the air. If it does not land right side up, the performance is continued until it does.

This is a large group, and many species are very common. Adults occur on foliage and flowers, under bark, or in rotting wood. Many apparently do not feed. Larvae (wireworms) are slender, shiny, and hard-bodied; they feed on plant or animal materials, and are found in rotten wood or soil. Some larvae are predaceous but most feed on roots or seeds. A few are very injurious to agricultural crops — they feed on newly planted seeds and the roots of various plants, including vegetables, cereals, and cotton. The Eyed Elater, Alaus oculatus (Linn.), is one of the largest (25-45 mm.) and most easily recognized species in this group; it has a salt-and-pepper color, and the pronotum bears 2 eyelike spots. The species of Pyrophorus, which occur in the southern states, are dark brown, 12-23 mm., and have 2 light spots at the rear corners of the pronotum that are luminous.

CEROPHYTID BEETLES Family Cerophytidae Not illus. Identification: Elongate-robust. Hind trochanters enlarged, nearly as long as femora. Antennae pectinate in 0" and serrate

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