26-June London’s Bug Circus: Jumpers, Stilts & Vampires

The infamous bed bug or Mahogany Flat Cimex lectularius is a close relation of flower bugs. It hides away during the day, waiting till the night to look for a blood meal. Its rare occurrence in London hotel bedrooms must be due to previous residents who have accidentally introduced it. A similar bug Oeciacus hirundinis is common, but never seen. This is because it lives on adult swifts which virtually never touch the ground. Having once rescued a swift caught in a fishing line, these bugs were happy enough to switch host, escaping rapidly on my hands and then up my arms.

The flattest bugs encountered around London are bark bugs which need to be flat, living as they do under bark and feeding there on fungi. The Pine Flat bug Aradus cinnamomeus is flatter and redder than most and feeds on pine sap in the Oxshott and Ockham area. Other bark bugs are often reddish brown or dark in colour with dimpled surfaces, short legs and short antennae. Typical species found in London are Aneuris avenius and Aradus depressus. As a group, they can often be found every month of the year living as they do in such a protected environment.

Ground bugs or Seed bugs unsurprisingly are found on the ground where they mostly look for and eat nutritious seeds. They tend to be relatively tough, black and brown insects with triangular shaped heads. They are common enough in a number of different habitats but get noticed more when they swarm. The European Chinch bug Ischnodesmus sabuleti swarms over reeds and sometimes cereal crops whereas Scoloposthetus decoratus swarms over heather. The Pine cone bug Gastrodes grossipes is one of the more brightly coloured species. It is a bright chestnut red and can be found on fallen pine cones in the Esher and Oxshott area.

Few insects capture our interest by the way they move, but stiltbugs are an exception. They are unremarkable, slender ground bugs with long spindly legs and swollen knees. They live in meadows and are usually not seen due to their secretive behaviour and habit of instantly freezing when disturbed. However, if one is noticed it is well worth watching for a minute or two as when it slowly and awkwardly moves off it does look as if it is walking on stilts.

Aphids are the most familiar of the homopteran bugs as well as being the most disliked. Not only do they attack the soft growth of a multitude of wild and cultivated plants, but they also introduce viruses and discolour leaves with their toxic saliva. They produce excessive amounts of honeydew, which then drops down from trees onto cars, where it blackens as it gets colonised by fungi. Possibly the two most disliked aphids of all are the greenfly and blackfly that reproduce so astronomically in the spring. These are all females reproducing without sex, creating great armies of identical clones. On warm days we sometimes notice winged aphids floating in clouds above gardens. They were called ‘smotherflies’ in the past. The numbers are such that we sometimes see birds catching and eating them on the wing. They can travel hundreds of miles in this way and, as many attack different host plants at different times of year, they end up affecting a vast range of plants. The rose aphid has a little more going for it than most being at least pink in colour.

There are a number of other homopterans that get noticed because they are good jumpers. Froghoppers e.g. Philaenus spumarius look like miniature frogs and like frogs they have big eyes and jump when surprised. Another group of jumpers are the leafhoppers. They are very numerous with over sixty different species having been recorded in Buckingham palace gardens alone. Their heads tend to be more triangular than froghoppers, giving the appearance that their eyes are set at the back of their heads. One of the most attractive is the candy-striped rhododendron leafhopper Graphocephala fennahi which can be found in Bushy park.

This bright green and red-striped species arrived from America in the 1930s and was first discovered here in Chobham. Since then it has been damaging rhododendrons far and wide across much of the country. As it feeds it often introduces a fungus that goes on to impair the development of the buds.

Jumping plant lice are also similar to leaf hoppers but smaller and with proportionally longer antennae. Their wings also tend to be more prominently veined making them look a little like cicadas. These are the ‘suckers’ that do so much damage in orchards e.g. apple and pear suckers Psylla spp. As they feed, they not only produce copious quantities of honeydew but also wax.

Some species excrete honeydew so rapidly they are called sharpshooters. If wax is seen on Box it is likely the plant is infested with the Box sucker Psylla buxi whose feeding habits result in the box leaves becoming cup-shaped.

A rarer group of jumpers are the treehoppers. These are only capable of small jumps and are recognised by the horns or extensions on their backs which make them look so much like thorns. If such a thorn is touched it often moves around the branch to escape any further persecution. They are sometimes found by sweeping the lower branches in woodland rides or orchards.

The Horned treehopper Centrotus cornutus can be found on Bookham common and the rarer Gargara genistae on Wanstead flats. The last group of jumpers are the Planthoppers. These are usually brown or green and caught whilst sweeping grass. They are unusual in having a large, moveable spur on their legs. Stenocranus minutus is a common species often found in patches of cocksfoot Dactylis glomerata.

Adult whiteflies look like miniature white moths, but it is not the adults but the nymphs that we notice. These are responsible for the spots of white powdery wax found on houseplants and in greenhouses all over London.

The main culprit is the Glasshouse whitefly Trialeurodes vaporariorum which attacks crops such as tomatoes and cucumbers. There are also outdoor species which attack hawthorns, Viburnum and ash trees. Other common greenhouse pests are the mealybugs. The females live their lives in a mass of wax which they exude from large pores in their skin.

One last bug we notice looks a little like blisters on the twigs of willow, lime, horsechestnut and various fruit trees. These are Scale insects, the ‘scale’ being made up of their moult skins cemented together. Female scales hardly resemble any other insect. They are oval, flattened, with no wings, hardly any legs and virtually no antennae. One species we see a lot is the Cottony cushion scale Pulvinaria innumerabilis which feeds on lime trees. The males tend not to be seen as they have such short lives.