24-June Midsummer Beetles & London Lore

Beetles

Two, three or four spines indicates it is a ‘greater’ whereas one spine indicates a ‘lesser’. The females may live as little as a month as an adult before they lay their eggs and then die. In the past they were believed to carry lighted coals and be responsible for thatched roofs catching fire. All three of our native stag beetles occur on Wimbledon Common. The third member of this family is the rhinoceros beetle Sinodendron cylindricum which has been found on rotten beech logs near Queensmere on the common.

Click beetles or skipjacks get their name from their ability to ‘click’ loudly. This they do whilst leaping to right themselves if they have fallen on their backs. They are usually elongated, with dull colours, and found in long grass. The wireworm beetle Agriotes obscurus is a common species and Stenagostus rhombus is one of the largest and most impressive. Both can be found on Wimbledon Common. Flower beetles, as their name suggests, are often found wandering around on flower heads.

One species which is noticed more than most is the thick-legged flower beetle Oedemera nobilis. It is a bright, metallic green beetle which appears to have shiny muscular legs. It can be found on Hutchinson’s bank.

Longhorn beetles are among the most arresting due to their absurdly long antennae. They are also often finely coloured and patterned. There are sixty different species in Britain, many of which are nectar feeders, if they eat at all. Ruislip and Ashtead woods are places where they may be found. The rare Agapanthia villosoviridescens, which has banded antennae, has been recorded on Horsenden Hill.

Two other impressive longhorns, Rutpela maculatum and Leptura quadrifasciata have been found in Oxshott wood. The timberman Acanthocinus aedilis is the most impressive of all. The male has antennae four or even five times as long as its body, perhaps up to seven centimetres in length. It breeds in remnants of the great Caledonian pine forests in Scotland, but occasionally travels down to London in transported pine logs. When the male flies, he trails his formidable antennae behind him.

Chafers e.g. the rose chafer Cetonia aurata look very like the scarab beetles ancient Egyptians set into rings. It is a sizeable beetle (2 cms) with unforgettable greenish-gold almost laquered wingcases. It also has the tell-tale short fanned antennae so typical of chafers generally. We still see garden chafers Phyllopertha horticola but far fewer of the larger chafers so loved by bats. Jewel beetles are famous for their bright jewel-like colours although those found in London are not particularly brightly coloured. They tend to be bullet-shaped with the tip of the bullet being their rear end. Agrilus pannonicus which has been found on Hampstead heath is perhaps an exception having a greenish gloss at its front end and a bluish gloss at its rear. Agrilus laticornis is similar and much more likely to be seen.

The rosemary beetle which is a leaf beetle is much more what you might expect of a jewel beetle. It is covered in bright iridescent purple and green stripes and easily seen on the rosemary and lavender plants in our gardens. Other leaf beetles are also brightly coloured, none more so than the famous Colorado beetle that attacks potato crops. One worth looking for is the mint beetle Chrysolina menthrasti which is a brilliant metallic green. It is found on mints in damp places. Leaf beetles are generally recognised by their often bright colours, their ladybird-like shape and their habit of drawing in their legs and falling to the ground when touched. Flea beetles are also leaf beetles. They often have thick “thighs” which they use to jump like fleas rather than drop to the ground.

At this time of year some of the most noticeable beetles we see are those on the flowerheads of umbelliferous plants such as hogweed. These are soldier beetles, so called because of their long narrow bodies and typical black and red military colours.

Sailor beetles are very similar but often more blue in colour and therefore more typical of the navy. Darkling beetles like so many others are usually a nondescript black or brown. Many are pest species to be found in stored products such as flour or dried fruit. The live mealworms bought in pet shops to feed birds and reptiles are actually the larvae of a darkling beetle Tenebrio molitor and, if left, quickly turn into adults. Other more typical darkling beetles live in rotten wood often in ancient woodland e.g. Cylindronotus laevioctostriatus in Dulwich woods.

There are other beetles that are easier than most to identify at least partially in the field. This can be for various reasons e.g. oil beetles have their enormous abdomens and cardinal beetles are often cardinal red in colour.

Pollen beetles are found massed in among the anthers of flowers and bark beetles in their galleries just beneath the surface of the bark on trees. Fungus beetles should be looked for on wild mushrooms and mould beetles eating mildew. Whirligig beetles are easy enough to encounter careering around the surface of ponds but click beetles clicking, bombardier beetles exploding or glow worm beetle larvae glowing less so. One last beetle worth an excursion to find is the small all gold leaf or tortoise beetle which inhabits the chalk meadows at High Elms. If picked up they often fly away immediately in a way that is highly reminiscent of the golden snitch in a game of quidditch.

It is also a good time of year to look for ladybirds, not just the common species already mentioned i.e. 2, 7, 10, 14 and 22 spot but also some of the less common species. The pine ladybird Exochomus 4-pustulatus is found in both pine and broad-leaved woods. It is mainly black with either four or eighteen red spots. The rare Adonis ladybird Hippodamia variegata can be found on rough ground within the Lee Valley. The orange ladybird Halyzia 16-guttata is larger and more striking than most. And has a preference for eating “mildew” on sycamore trees. Occasionally alien ladybirds such as the Australian vedalia beetle Rodolia cardinalis turn up on imported plants, but it is the voracious appetite of the recently arrived harlequin ladybird Harmonia axyridis that is still causing the most concern. The name Harmonia may be propitious. In mythology, she possessed a necklace which brought misfortune to anyone who wore it. Its arrival could potentially be a great misfortune for our resident ladybirds as it can have two or three generations a year and is still an active predator when other ladybirds are hibernating.