Thursday, 10 October 2024

Urban bush-crickets: Long-winged Coneheads

The Long-winged Conehead, together with the Roesel's featuring in the previous post, are the two most common bush-crickets in the UK now, and the most commonly found in urban settings. This wasn't always so, in fact, Long-winged Coneheads are relatively recent arrivals, with the first records in the south English coast in the early 1940s. Aided by those long wings and full flying abilitties, their unfussy habitat requirements, and climate warming, the species moved north swiftly, and currently the northernmost records reach North Yorkshire.

A female nymph. The straight ovipositor makes identification of females nymphs possible.

This is a long, thin bush-cricket, about 15 mm long. Nymphs are usually bright green with a dark back, and adults are more variable in colouration as the top shot illustrates, whilst keeping a darker dorsal stripe lined with yellow. Your eyes will be quickly drawn to the straw-coloured female and her long, straight ovipositor, but look again and you will see the green courting male behind her!

Behaviour. Long-winged Coneheads are in their element on long rough grass, where they are beautifully camouflaged. They are very alert and agile insects, and quickly hide behind a blade of grass if disturbed, or jump onto vegetation and dive down.

A female Long-winged Conehead in typical pose, ovipositor alongside a blade of grass.
After I got too close, she deftly hides behind the grass, only her legs claspling the blade visible.

Males tend to perch high on blades of a tussock of grass and stridulate to attract females. They call mainly during the day in sunny, warm weather, but also in cool weather provided it's sunny. In cool, autumn days, they like to bask on vegetation, often making themselves more exposed on logs or leaves, and lean to expose the side of their body to the sun, with a lowered, extended hindleg. Females lay eggs inside plant stems and most adults will be gone by late October, early November. The next generation will emerge in May or June. Long-winged Coneheads are not particularly social, but it is not uncommon to spot some individuals basking almost next to each other.

Basking female (above) and male Long-winged Coneheads.

Field craft. Whilst slowly walking across grass, watch ahead for movement, and try to spot landing sites. If you carefully crouch nearby, coneheads will soon move onto higher perches and expose themselves. You can also scan suitable basking sites with or without binoculars. Approach slowly and carefully to avoid disturbance. Stridulation is a continuous reel, inaudible for most people as it peaks about 26 KHz. A bat detector is very useful, their call sounding like a helicopter or generator. The presence of stridulating males is a good way to detect a new population in a site with little effort, and then you can use other methods to spot individuals. You can also try to pinpoint a calling male by scanning with the bat detector, but I find this difficult, especially if populations are dense and there are many calling males nearby.

A calling male Long-winged Conehead.

A trick to make them expose themselves is to move your hand slowly around and behind the grass and watch as they respond by moving round away from your fingers, and making themselves visible to you, like so:

This way I can check the shape of the ovipositor, which distinguishes this species from the Short-winged Conehead, without needing to capture the individual.
 A female stops basking and cleans her ovipositor.

Habitat. This is a very generalist species, and I find it in sites where there are not even grasshoppers. Any patch or strip of tall grass, including ungrazed grassland, reedbeds, brownfield sites, river or ditch banks, roadsides or verges and even heaths can hold populations. Rough grass appears to be colonised rapidly once mowing stops.

A plot of land in the city that hasn't been mowed in a couple of years with a population of Long-winged Coneheads.
Long-winged conehead basking.

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