Longhorn Beetles (Cerambycidae)

There are many members in the Longhorn Beetle family: some 15,000 species all over the world. In Western Europa alone some 100 species have been spotted. Longhorn Beetles usually do have very long horns, even though there are exceptions, of course. Many are also nicely coloured and they all give a slender impression. A few Longhorn species are very dangerous. Their larvae eat dead wood and do live inside pieces of wood in buildings. And because you can't see them (they do make little holes like the woodworm does) and because they can live as larvae for some 5 to 7 years, it may be too late once you spot the adults. Most species however are not dangerous, but live in stems of plants or reet. The species to the left below for instance spends its larval stage in stems of thistles. Some flies pretend to be dangerous by imitating wasps or other dangerous insects. In this way they hope to be left alone by enemies. Some beetles try the same trick, like the Wasp Beetle below. It looks like a dangerous wasp. But when you look carefully you will notice there are no visible wings. This means this is a beetle and not a wasp. So, it can not even sting you, it just uses a wasp's colours to trick potential enemies.

A continental Longhorn-species (Agapanthia villosoviridescens) to the left and a Wasp Beetle (Clytus arietis) to the right.

In most beetle species the male and the female are almost identical. In a few cases however there are striking differences between the two, like in Corymbia rubra, a species common on flowers in gardens. The male is slender, brownish and has a black neck shield. It seldomly reaches a length of over 15 mm. The female is bigger and more plumb, reaching some 20 mm in length regularly. She is reddish, including het neck shield. Actually they do look like two separate species! The species is very rare in the UK, for the foodplants of its larvae are not indigenous in Britain. It is still often referred to by either of its former scientific names Leptura rubra or Stictoleptura rubra.

To the left the male and to the right the female of Corymbia rubra.

The Longhorn below to the left is smaller, reaching a length of some 16 mm. The sexes are look a likes and the same size. It is yellow showing black markings. These markings are extremely variable. Animals that are almost entirely yellow are in existence, and animals almost completely black have also been reported. It is a very local species, even though it may be abundant. It is also seen on flowers in gardens regularly. It is even called the Flower Longhorn in Denmark! The larvae live in old tree stumps. For a long time it was known as Strangalia maculata, but was then placed in the Leptura genus. Stenurella melanura, to the right below, used to be in the genus Strangalia too. In this case male and female differ from one another. The male has yellowish brown shields, which are black at the sides and near the end. The shields of the female are reddish brown and have black edges as well, but they are smaller than the males's. Both sexes like to sit on flowers in the sunshine. The larvae live in rotting, often somewhat moist stems and thick branches, laying on the ground.

Leptura maculata, to the left, is a local species. If present though, it might be appearing abundantly. Stenurella melanura, to the right, is a much rarer species.

The beetle below is a Longhorn as well. We couldn't discover an English name, so it is possible this animal doesn't live on the British Isles and in Ireland. In our garden is is a common species. It is easily identified by the shape of the shields, the colour and especially the thickened thighs: black on the front and middle legs, red on the rear legs.

This is a small, but striking Longhorn beetle: Stenopterus rufus.

One of the most remarkable Longhorns probably is the species depicted below. Not only does it have bulky thighs, the shields are very small as well. Each shield has just one white stripe. The abdomen is much longer than the shields are. The wings however have the usual length and cover the naked body. It does look like the Rove Beetles a lot, but these have very short antennae. Molorchus minor however has the usual longhorn antennae. At first glance the animal also looks like a parasitic wasp. It lacks the typical wasp waist however. It also does look like an earwig, but it lacks the pincers and unlike earwigs, which fold their wings under their little shields, the wings of this beetle are always visible. It is a conifer species and not very common.

This curiously shaped longhorn is called Molorchus minor.

Many Longhorn Beetles are quite big and thus easily noticed. There are also quite a few very small species though. Take the beautiful Plumb Beetle below. It is named after its host plant, for the larvae are found in twigs of plumb trees. It likes other trees and shrubs as well, including roses. This animal is probably often overlooked, for it reaches a length of 3 to 6 mm only. Usually it takes the larvae 1 year to develop into an adult beetle, but sometimes they need two years to develop. The entire animal is strikingly hairy. The thorax shield and the tips of the elytra are kind of black, but under the right light circumstances they may turn into a wonderful, metallic blue. This species is very common all over Europe and has even reached Northern America. The scientific name Tetrops praeusta is still often used for this species, but it is wrong, for Tetrops apparently is a male word.

A very small Longhorn Beetle: the Plumb Beetle (Tetrops praeustus). In direct sunlight the black parts might reveal a beautiful metallic blue colour.

Below we like to introduce a very small longhorn beetle. It is a dark, not very colourful species which reaches a length of 3 to 7 mm only. From some of the similar dark species it can be told apart by its ringed antennae. The larvae just live for one year under the bark of moulding and rotting wood. They are found in trees, such as willow and oak and in shrubs, such as blackberries and ivy and even in cultivars such as berberis. The adults are often seen on flowers and frequently encountered on Hawthorn, Dog-rose and Bramble. This is a common species in Europe, including all of the British Isles, Russia, Turkey and Western Asia.

This small, dark and rather non descript long horn beetle is called Grammoptera ruficornis.

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