SHIELDBUGS

Shieldbugs are among the most familiar insects in the Hemiptera order. While many of us may refer to any small invertebrate as a bug, only hemipterans are ‘true’ bugs. What makes an insect a hemipteran? It sucks – truly. Hemipterans have mouthparts that can pierce plants and suck the juices out of them. The almost 2,000 hemipteran species in the UK include aphids, leatherbugs and water bugs, such as pond skaters.

BRASSICA SHIELDBUG

Both the common name and scientific species name point to where this shieldbug is usually found – on brassica plants, such as garlic mustard and horseradish. Also called the crucifer shieldbug, it is found in southern and central England. It is mostly dark blue-black, with coloured markings on its body that vary between individuals: red, yellow or cream-white. It can be mistaken for two similar but rarer species: ornate shieldbug and scarlet shieldbug.

HAIRY/SLOE SHIELDBUG

This large species is covered with visible hairs, even as a nymph. It is a lovely purple colour with a pale tip to its scutellum (which darkens prior to hibernation), and black and cream banding on its antennae and connexivum (edges of the abdomen). Its other name, sloe shieldbug, indicates an association with blackthorn, but it can actually be found on a wide variety of plants. It is common in much of England, Wales and southern Ireland.

BRONZE SHIELDBUG

The bronze shieldbug is a predatory species. It feeds on tree sap as a nymph, but then begins feeding on other insects, particularly caterpillars. Some other shieldbug species have a similar colouration, so one of its key identification features is the banding on the antennae – it has a single yellow-orange band on the penultimate segment of each antenna. The bronze is a woodland species found on both deciduous and coniferous trees.

PARENT SHIELDBUG

The parent bug is reddish-brown in colour, usually with a distinctive black band across the middle of its scutellum, and with black and white bands on the connexivum. The species is named for its unusual behaviour. Typically, shieldbugs lay their eggs and leave them to fend for themselves, but the parent bug is different. Although the male dies soon after breeding in spring, the female broods the eggs and stays with the hatched nymphs as they develop.

GORSE SHIELDBUG

The gorse shieldbug has two quite different colour forms. In spring, an adult born the previous year emerges from hibernation (pictured) and is green with red-tipped legs, red antennae and yellow on its connexivum (edges of the abdomen). When an adult from the new generation appears in late summer, it has a darker pronotum (shoulders) and wingcases and green-ish scutellum (triangular shield on the back). It is found on gorse and broom.

HAWTHORN SHIELDBUG

One of our green-and-red shieldbug species, the hawthorn is the largest shieldbug in the UK. It grows up to 17mm in length and is common and widespread across most of the country. As the name suggests, the nymphs can usually be found on hawthorn where it feeds on haws, but it also feeds on deciduous trees. The species overwinters as an adult, and can become darker just before hibernation. It emerges in spring to mate.