Hawthorn Shieldbug

Hawthorn Shieldbug, Acanthosoma haemorrhoidale (L.), resting on a lichen-covered beech tree trunk on a chalk slope in south Dorset, UK. It is a striking shape with bright green and rusty coloured body. The hard parts of its exoskeleton have numerous small pits.

It is a Land Bug: Class Insecta, Order Hemiptera, Sub-Order Heteroptera, Superfamily Pentatomoidea, Family Acanthosomidae. The shieldbugs are called that because of their general shield-like shape. They are also called Stinkbugs because some species produce a pronounced pong. The bugs in the Acanthosoimidae are different from the bugs in the other four families in having only two tarsal segments on the legs. The Hawthorn Shieldbug feeds mainly on hawthorn fruit but it survives overwintering by eating just the hawthorn leaves in spring.

The terrestrial bugs as a whole are essentially a tropical group and many of the British families are right at the edge of their range here: many of the species are only found in the southern counties. Our damp climate is more to blame than our latitude because the bugs reach further north in continental Europe. Many of our species, particularly the larger ones, hibernate among grass tufts or in the upper layers of the soil where they are very prone to attack by fungi in damp weather. Winters on the Continent are often considerably colder than ours but they are also drier and the bugs survive better. It is significant that most of our ground-living bugs are found in the drier areas of the south and east – on the better-drained chalk and sandstone areas – or on sand dunes around the coasts, Our somewhat low and rather unpredictable summer temperatures, however, are probably just as important as the winter damp in denying us a richer bug fauna.

Michael Chinery, A Field Guide to the Insects of Britain and Northern Europe, Collins, 1973, ISBN 0 00 212036 4.