What Bug Is That? The guide to Australian insect families.

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Eucnemidae

Overview

Most larvae occur in dead wood, but their food source and the mechanics of their locomotion through this substrate are still matters for speculation. They are liquid feeders and there is no evidence that they are predators; it is possible that they digest wood fibers extraorally, but they may also feed on slime mould plasmodium or some other nutrient-rich fluid within the wood. Larvae of the exotic Phyllocerus live in soil (Gur'yeva and Valiakhmedov 1982), and it is possible that some Australian species have the same habit.

Description

Elongate, cylindrical to slightly flattened, compact beetles, usually finely pubescent and with acute posterior angles on pronotum. They closely resemble Elateridae in the form of the prothorax and in the possession of a clicking device involving the prosternal process and mesosternal cavity, but they differ from all elaterids in having the labrum concealed beneath the clypeus, all 5 ventrites connate, and the antennae sometimes received in grooves just beneath the lateral pronotal carinae or ventrally crossing or bordering the notosternal suture. The tarsi are usually simple, but in Galbites they bear membranous appendages on segments 2--4.

Larvae usually flattened, with no legs and reduced head with minute antennae and non-opposable or immovable mandibles. There are two common larval types: that found in Fornax and its relatives, in which the body is parallel-sided with a sclerotised, wedge-like head, and another, characteristic of Trigonopleurus and related groups, which resembles a buprestid larva in having an enlarged prothorax bearing rod-like sclerotisations.

Distribution

Hemiopsida is probably the largest Australian genus, and Galbites is a distinctive Melanesian genus which extends to Cape York. [Cobos 1964; J. C. M. Gardner 1935; Mamaev 1976a; Muona 1987.]

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