Small World Discoveries

HEMIPTERA > HETEROPTERA > PENTATOMORPHA > ARADOIDEA > Aradidae

The members of this small family, commonly known as either flatbugs or barkbugs, are primarily fungal feeders that live most of their life under the bark of decaying trees. They have a flattened body, strong legs and short antennae, which enable them to crawl into tiny crevices where they are obviously very difficult to find. Occasionally they may be seen on the surface or on wood debris on the forest floor, but unless you're specifically looking for them, encounters are likely to be very few and far between.

In fact, of the seven species that have been recorded in Britain, only four are normally considered and only two of those are likely to be found in my area. Aradidae is quite a large family worldwide, but in Britain we have just two genera; Aneurus with two very similar species, and Aradus with five species.   

Aneurus laevis is a dark reddish-brown species, about 4-5mm long with a broad, flattened body and completely membranous wings apart from at the base. The forewings are developed, but the rear wings are greatly reduced effectively reducing their ability to fly. They occur in woodland under the bark of dead, rotting, mainly coniferous trees, which are affected by fungi. Aneurus avenius is extremely similar and if I happened to find a specimen from this genus, I would seek help in confirming its identity. They are common in England and parts of Wales, rarer further north, but are seldom recorded.

Aradus depressus is the most widely distributed flatbug and the most likely to be encountered. Unlike the two Aneurus species, the wing membrane in Aradus does not extend below the apex of the scutellum. Adults are brown with whitish, reddish and black markings, but are distinguished by the pale shoulders. It is a tad larger than the other species, at 5-6mm. They also occur in woodland, but are more likely to be found on native deciduous trees. The common name of Pale-shouldered Flatbug is often used to identify the species.

I've found nymphs on a couple of occasions, but have yet to see an adult.

The other species Aradus cinnamomeus, commonly known as the Pine Flatbug, seems to be pretty much restricted to Surrey heathland where it can occasionally be found on Scots Pine feeding on sap, rather than fungi like other flatbugs. It is a reddish-brown colour and grows to much the same size as the two Aneurus species. It has only been officially recorded a few times and, from current records, is probably very unlikely to be found on Dorset heathland, but with all under-recorded species it's best to keep an open mind.