Posted by: lensweb | March 10, 2018

What is a Longhorn Beetle?

 

Beetles have hardened backwings called elytra and biting mouthparts and undergo complete metamorphosis, from egg to larva to pupa to adult. There are at least 380 000 species worldwide, 4000 British species (and counting).

The Cerambycidae are the longhorn beetles, in Greek mythology, Cerambus was a musician who angered the gods and was turned into a beetle.  Worldwide there are more than 30,000 species of longhorn beetles described to science, in Britain 69 are considered native or naturalised while many other species are recorded as occasional imports.

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Longhorn beetles, or cerambycids, are very distinctive and beautiful beetles.

  • General appearance is generally elongate and robust
  • Elytra can be brightly coloured or patterned
  • Long antennae, sometimes longer than the beetle although some have very short antennae (Rhagium spp.). Can be filiform or serrate.
  • The feet (tarsi) have five segments but in most species the fourth segment is hidden

The life cycle begins with the female beetle laying eggs in rotting fungus, living or deadwood. Once the eggs hatch, the larvae begin feeding upon their food source. The length of time spent in the larval stage varies among species but this time can range from months to years. Adult beetles begin to emerge from April to August and are often found on flowers such as the ‘giant landing pad’ of a hogweed flower or on recently-fallen or felled timber. Some may be found by beating bramble with an upturned umbrella or spreader underneath.

The titan beetle (Titanus giganteus) is a neotropical longhorn beetle, and at 167 mm is one of the world’s giants. In the UK, The Musk Beetle Aromia moschata is a large beetle (up to 35mm long), it is elongate longhorn with dull green reflections, a knobbly pronotum and very long antennae, it emits a musky smell when threatened. It is widespread but decidedly local with a liking for older wetlands with mature willows. The Variable Longhorn Stenocorus meridianus is a large beetle reaching up to 25 mm in length and is a clumsy flier. The wasp longhorn Clytus arietus, has a jerky movement like a robot. The Golden-bloomed Grey Longhorn Agapanthia villosoviridescens has a common name longer than the Latin name. The logo for the longhorn beetle recording scheme, is the spotted longhorn Rutpela maculata which has a variable pattern of spots and stripes. It used to be called Strangalia. The rufous-shouldered longhorn beetle Anaglyptus mysticus is rare. The beautiful Tawny Longhorn beetle Paracorymbia fulva has golden brown elytra (wing cases) are tipped with black  and is 9-14 mm long. The larva has never been found.

Be on the alert for an invasive alien. One of the best looking and unmistakeable longhorns the Asian Longhorn Anoplophora glabripennis is purple with white spots.  Asian longhorn beetles and the closely related Citrus longhorn beetle could potentially infest a very wide range of broadleaved trees and would be a major threat to horticulture and the wider environment if they became established

Longhorns are of great ecological importance in many ecosystems, many species provide an invaluable pollination service and the larvae eat decaying matter, in turn recycling nutrients through the ecosystem.

These brightly coloured distinctive beetles lend themselves uniquely to identification by photography. All can be IDed with confidence from photographs except 4 rarely found longhorns. A Field Studies Council Identification Chart is in preparation.

The Longhorn Beetle Recording Scheme is organised by Wil J. Heeney and Katy Potts, who took it on in early 2016.

http://www.coleoptera.org.uk/cerambycidae/home

Records accompanied by a photograph are welcomed either via i-record or send a spreadsheet to longhorns@brc.ac.uk.


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