Overview
Cylas formicarius elegantulus
is an introduced pest of sweet potato in eastern Australia, while many Apioninae are known to feed on the pods of legumes. A species of
Nanophyes
was found feeding in the stems of
Ludwigia
(Onagraceae), an aquatic plant. Larvae of Brentinae are usually found in wood, and some Calodromini utilise the galleries of scolytine and platypodine weevils. [J. C. M. Gardner 1935; Kissinger 1968; Morimoto 1976.]
Description
Moderately to very elongate, parallel-sided to anteriorly narrowed beetles, usually subglabrous but occasionally clothed with decumbent or erect hairs. Rostrum usually long and narrow (short and broad in some Brentinae); antennae straight with short scape, except in
Nanophyes
, where antennae are geniculate with very long scape; antennal club, when present, may be long and distinctly segmented (Eurhynchinae, Nanophyinae, some Brentinae), short, compact and indistinctly segmented (Apioninae) or unsegmented (Cyladinae); antennal insertions usually between base and middle of rostrum, but occasionally near apex; labrum not visible; maxillae and labium reduced, with rigid maxillary palps and labial palps reduced and usually concealed on inner surface of labium; gular sutures fused; prothorax without lateral carinae; pygidium concealed by elytra; first 2 ventrites solidly fused and much longer than ventrites 3--5 combined. The subfamily Brentinae includes distinctive beetles which may be very long and narrow, usually have more or less moniliform antennae, and may exhibit strong sexual dimorphism; males have a flattened and apically expanded rostrum and large mandibles and females a narrow, straight rostrum with minute mandibles.
Larvae slender and subcylindrical or short and broad, moderately to strongly curved and very lightly sclerotised. Frontal arms extending to mandibular articulations; labrum with pair of sclerotised rods; mesotergum armed with paired patches of asperities in some Brentinae; abdominal terga with 2 or 4 transverse folds; legs, if present, minute and sometimes consisting of dome-like lobes only.
Distribution
There are 5 subfamilies in Australia: Eurhynchinae (
Eurhynchus
and
Aporhina
), Cyladinae (
Cylas
), Nanophyinae (
Nanophyes
), Apioninae (
Myrmacicelus
,
Apion
and relatives), and Brentinae, with a number of genera.