Hemiptera - true bugs

Fast facts about Hemiptera (true bugs)

  • Have piercing mouthparts, called a rostrum which contains 2 pairs of stylets. The outer 2 pairs (the modified mandibles and maxillae) have serrated edges for piercing, and the labium and labrum form a tube around the stylets for food to pass up and saliva to pass down. The tip pf the rostrum has receptor cells to assess the suitability of the food source.
  • Mouthparts usually fold under the body like a clasp knife.
  • Adults usually have two pairs of wings, the front pair may be partially hardened.
  • The plant feeders can be serious agricultural pests as they can transmit viral diseases.
  • Body length from 1 mm to 130 mm.
  • Divided into two sub-orders; Heteroptera and Homoptera.
  • Cuckoo spit is made by a Homopteran bug.
  • Over 100,000 species worldwide, over 8,000 in Europe, 1830 in the British Isles.

Heteroptera

Homoptera

Wings divided into 2 parts, one part being leathery. Includes shield bugs (this page), bedbugs, water striders, pond skaters, and other water bugs. Wings entirely membranous or hardened. Includes cicadas, leafhoppers, froghoppers, aphids.
All homoptera are plant feeders.
Assassin bug, Reduviidae

Hemiptera taxonomy

The taxonomy of the hemiptera is confusing, and is constantly being changed. In many books they are subdivided into 2 groups as above, however this division is often changed to incorporate extra divisions.

Heteroptera body shape

Left a heteropteran land bug. Their bodies are generally flattened, with the wings folded flat over the body. The mouthparts (stylets or rostrum) form two channels allowing food to be sucked up one and saliva to be pumped down the other (see the diagram of a bug head below).

The bug on the left belongs to the Pyrrhocoridae family, many of which are seed eaters. This is Pyrrhocoris apterus (the fire bug), and is the only member of the family found in Britain, though it is not common. In Europe it can sometimes be seen in huge numbers in spring crawling through the vegetation.

Picromerus bidens

The drawing on the right shows the typical bug head.

Picromerus bidens

The shield bug on the left and below is Picromerus bidens, one of the 17 species in the Pentatomidae family in the U. K. There are about 5000 species world wide, and around 20 British species, and as their common name suggests the body is shield-shaped.

Picomerus bidens is 13 - 15 mm long when fully grown, and has 2 spikes jutting out from its thorax. It is commonly seen from June - September.

If you are a gardener and you come across this bug then cherish it as it eats the poisonous caterpillars and leaf-eating beetles that birds cannot. It is fairly common in and around woodlands from late summer onwards.

bug head, true bug head diagram naming body parts, heteroptera head
Picromerus bidens

The female lays eggs in batches of around 30 at a time on the stems and leaves of shrubby plants in the autumn. In the summer the eggs hatch and do feed on plants at first, but then move on to caterpillars and beetles. In milder areas it is possible for the adults to overwinter, but in cold areas all the adults will die off, with only the eggs surviving the winter cold.

In the photograph above right you can just see its rostrum or beak folded under its body.

 

Picromerus bidens
Reduvius personatus, the assassin bug

Assassin bug, masked hunter, bed bug hunter, the kissing bug, Reduvius personatus

On the left is Reduvius personatus, the assassin bug, or masked hunter. The name masked hunter is attributed to the nymph which has a sticky body surface which can become covered in debris.

Fully grown adult length is 17 -22 mm. The colour is brown/black. It is common in Europe and the US and adults are commonly seen in June and July. Both adults and nymphs suck the contents of bed bugs, lacewings, earwigs, and anything else they can find.

If handled they can give a painful stab, but do not normally feed on mammal blood, so they do not transmit diseases to mammals. The stab is only in defence. They are active mainly at night.

Adults can stridulate (produce sound by rubbing body parts together) by rubbing their back against their prosternum (first segment of its thorax). They are usually found around and in houses.

Also in the Reduviidae family is Platymeris rhadamanthus, the Red Spot Assassin from Africa. As its common name suggests it is red or orange and black. This bug can spit up to 30 cm and its saliva can cause intense pain and swelling if it hits the eye or nose. It can kill prey many times its size, and can live for 2 - 3 years. Adults are around 4 cm long, and recently it has become popular as a pet. When kept in captivity it can be fed on worms and crickets.

Acanthosoma haemorrhoidale, hawthorn shieldbug

Anthocoridae, Flower bugs

On the right is Anthocoris nemorum, the common flower bug. Body length 3.5 - 4.0 mm. It has a black head and prothorax, with a black, red/brown and white abdomen.

It feeds on plant lice, aphids, thrips, mites and insect eggs, so if you're a gardener it is a good thing to have on your plants. It can also suck plant sap, but cannot survive on a wholly vegetarian diet. Its proboscis can pierce human skin, and may leave an itchy spot.

The eggs are laid in the spring by females who have mated the previous year. In most years non-mated females and males do not survive the winter.

Acanthosomatidae family

This family of shieldbugs differ from most others as their tarsi (segments of the feet) have only 2 segments instead of the more common 3. There are 5 British species.

The hawthorn shieldbug, Acanthosoma haemorrhoidale (left), is one of the most common. As its name suggests it lives off hawthorn flowers and berries, and the overwintering adults feed on the leaves.

Adults are 13 - 15 mm long, green and brown, and some have red shoulders. The female lays eggs in batches on the undersides of leaves; around 20 eggs in each batch. The eggs hatch in around 9 days and the young remain near the shells until after their first moult. Then they begin feeding.

There is one generation a year and they overwinter as adults. They tend not to be found as far north as Scotland.

Anthocoris nemorum, common flower bug
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