Elateridae part 2

I already did an entry about the family Elateridae, but I received a very recognizable click beetle from Kit's mom in Virginia. It is the species Alaus oculatus, or the Eyed Click Beetle. Unlike the tiny brown click-beetles we find here on the west coast, which are barely 1/2 inch long, the Eyed Click Beetle is 25-45mm long, and is decorated by white specks and eye spots: large black circles outlined in white. It is commonly found in deciduous forests and woodlands. It can be found most of the year, but most commonly in the spring and summer. The larvae are predatory, feeding on the larvae of other insects, particularly boring beetles like Cerambycids. The adults may feed on nectar and plant juices, are winged, and are attracted to lights.

Coleoptera; Polyphaga; Elateroidea; Elateridae; Agrypninae; Alaus oculatus
Common Names: (Eastern) Eyed Click Beetle, Eyed Elater

I always liked click beetles as a kid - they were harmless, flicked their bodies interestingly...I had never imagined they could get as large as this. It truly is a remarkable insect. The one pictured above is approximately 40mm long, and is actually the largest species of click beetle. Most elaterids are mottled-gray/brown/black and reach lengths of 12-30mm.

Elateridae

This entry is devoted to the familiar click beetle, family Elateridae. Their clicking ability is derived from having a flexible junction between the prothorax and the mesothorax, which in beetles is normally fused, and there is a prosternal spine that fits into a groove on the mesosternum. The diagram below compares the ventral arrangement of a click beetle (A) with that of a metallic wood-boring beetle (B), which is of the family Buprestidae, featured in an earlier entry.

sp: prosternal spine; stn1: prosternum; stn2: mesosternum;

The shape of click beetles is very unique - the body is elongate, usually parallel-sided, and rounded at each end. The posterior corners of the pronotum are prolonged backward into sharp points or spines. Most of these beetles are 12mm-30mm in length, and one common species is a mottled-gray click beetle with two black eye spots. Most click beetles are black or brown. The larvae of click beetles generally live in rotting logs, and are slender, hard-bodied, and shiny - also called "wireworms." The adults are phytophagous, and so eat plant materials.

Coleoptera; Polyphaga; Elateroidea; Elateridae;
Common Name: Click Beetle