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.

Urban bush-crickets: Roesel's Bush-cricket

I'm starting a daily series on urban bush-crickets. Checking through the blog, I realised I haven't paid much attention to these newly arrived species in the city. In 2022, I undertook a survey of urban bush-crickets, after I was made aware of the presence of several species in the city of Hull. It was an exhilarating summer: armed with a heterodyne bat detector, I explored grassy areas, marshland and brownfield sites across the city, listening for them or trying to spot them. The last two summers, I have continued with the surveys, as I have really got the bush-cricket bug! With this series, I want to write what I wish I had known when I started regarding each of the species.

Female Roesel's Bush-cricket basking, Rockford Fields, 9 October 2023. Note the curved, relatively short ovipositor and short wings.

The Roesel's Bush-cricket, Roeseliana roeselii, is a stocky species (top shot, a calling male at Sculcoates Cemetery, 28 September 2024). On first impression, if you see one scuttling through grass you think it's a small toad, as they physically disturb the vegetation with their bulk as they move. The size and colour is variable. The most common form is brown and yellow, with some green touches, but some individuals can be very green. The rim of the black side of the saddle-shaped thorax is white, yellow or green. Three yellow spots just above the base of the legs, on the thorax, are distinctive, as is a black comb-shaped stripe across the jumping legs. The species is wing-polymorphic. Nymphs growing in dense populations tend to develop long wings and are able to fly long distances. The long-winged form is responsible for long-distance dispersal and colonisation of new areas. The most common form has short wings, extending half way through the abdomen, and is unable to fly. Females are larger than males and have a short ovipositor, curved upwards. Males have modified forewings, which they use to sing (stridulate). They lay their eggs in plant stems. During mating, males provide females with a nuptial gift called 'spermatophylax' which makes a substantial proportion of males' weight. 

A male long-winged Roesel's form calling.

Behaviour. Individuals like to bask in sunshine, often quite exposed, especially in cool mornings in the autumn. Sometimes they will stretch out a jumping leg to expose the abdomen to the sun. Males start to sing while basking, choosing grass tussocks as a perch. Tussocks offer individuals protection from predators: at the slightest disturbance, they drop onto the base of the tussock and scramble into it. They are not particularly social and will compete for a good perch or sunny spot.

Roesel's are very well camouflaged in their environment and can be tricky to spot. Try to find a calling male Roesel's male from a perch on tall grass. (tip: the Roesel's is at the bottom third of the centre of the image. There is also a Long-winged Conehead on the centre top third.

A typical urban unmown field holding Roesel's.

Habitat. Thought to be associated to salt-marshes and dunes, the species has been shown to be little limited by habitat and can now be found along road and path verges, grassy fields, brownfield sites, and any habitat that includes rank grasses. 

A Nymph Roesel's busch cricket. 28th May 2023, my first observation of the year for the species.

Field craft. How do you find Roesel's bush-crickets? The first nymphs appear in mid to late May. Nymphs can be found by sweeping grass with a net. Adults appear at the end of July, and are best searched for. Male's stridulation is within the human audible range, but it is a high-pitcher whirr, that is easier to hear for children. Many middle age people are unable to hear them at all, so using a bat detector set to 20 KHz makes it easier to detect them. The call is a continuous whirr that has been compared to an electric buzz. Once you are close enough so that the sound is quite loud, you can try and pinpoint where the calling male is perched by swaying the bat detector left and right and up and down. I find binoculars very useful, to scan suitable perches from a couple of meters with minimal disturbance to spot individuals. With a bit of luck, once located, using slow movements, they can be approached to close range. Males tend to call during the day in sunny weather, unless they are already warm, then they will carry on calling. Searching at suitable sunny spots for basking individuals can also be rewarding, especially on bramble leaves next to grass, where they can be more obvious. Roesel's season winds down as October progresses and the last adults die off with the first frosts, their eggs surviving in grass stems over the winter. 

A long-winged female Roesel's. I saw it flying and landing on the short grass of a playing field (31st July 2020), this is the only photo I took, as it immediately flew north. 

Range expansion. Roesel's have undergone a spectacular range expansion in the last decades, from the south east corner of the UK. The first record in Hull was in summer 2015. They are now widespread in East Yorkshire and the northernmost populations are currently in North Yorkshire (at Robin Hood's Bay), but the colonisation is ongoing, aided by climate change and by long-winged forms that appear once population density is high.

A mating pair of Roesel's Bush-crickets. The female is much larger and above, whilst the male hangs underneath the female.

A female eating the spermatophyllax.

Red Admiral at windfall fruit

Any sunny spell of weather these days and you are likely to come across a Red Admiral, basking or  nectaring on flowering Ivy. Red Admirals are generalist butterflies and late flowering Buddleia, Asters or other late blooming bushes will be used too. Red Admirals are also partial to fruit, and rotting, windfall pears or apples attract many individuals. Last week, a pear and an apple tree at a car park provided a glut of food for Red Admirals and wasps alike. About a dozen Red Admirals were around, either feeding on the fruit under the trees, wings closed, or basking on leaves with their wings fully open. Wasps were also feeding on the fruit, but the butterflies were not keen on sharing their table, so every time a wasp got too close the Red Admiral flicked its wings open (top shot) and flushed it out.

A basking fresh individual.

Ivy bees in Hull

 I have spent some time watching mature Ivies lately. It is Ivy peak flowering season, and the couple last days have been warm and sunny, bringing the insects out, the ivies humming with insect activity. Droneflies, Red Admirals, Comma, Wasps, honeybees are attracted to flowering bees. I was actually looking for Green Mesh Weavers, on an Ivy in an untarmaced tenfoot (alleys between houses) when I noticed two stripy bees rummaging around the leaf litter at the bottom of the ivy. I couldn't believe they were Ivy Bees, Colletes hederae! I have previously seen Ivy Bees in east Yorkshire, at North Ferriby and at Flamborough, but I thought we wouldn't get them in Hull due to our clay soils, as this bee needs loose soils for nesting. 

Two bees exploring the soil under the ivy, this is probably loose enough and sunny enough for a nest site?

A winner from climate change

Ivy Bees started colonising the UK from 2001, after expanding in northern Europe, and in the last couple of decades its distribution range has rapidly expanded northwards, with the first Scottish records coming in 2021. The mail pollen source for its larvae is Ivy, and the bee flight period coincides with the flowering season of ivy, from September to early November, with a single brood. They are solitary bees but they tend to nest together, sometimes forming large nesting aggregations in suitable habitat. Females will excavate a nest and line the walls with a cellophane-like substance, which explains another name of the bee, Cellophane Ivy Bee. Ivy pollen is brought to the nest and an egg is laid atop a mound of pollen, before the cell is sealed and another load of pollen is collected for the next egg.

One of the Ivy Bees near the ground after some exploring.

A female laden with pollen having a rest to clean its tongue.

A foraging female showing the banded abdomen. This bee is relatively large, the size of a honey bee, with orange hairs on the thorax, and contrasting broad buff bands in the abdomen, unlike its close relative the Sea Aster bee, which is smaller and has a white banded abdomen. Habitat, timing and foraging flowers can also help distinguish these bees.

The Green Meshweaver gets to Hull

 

Another post on a rapidly expanding species, this time a small spider, the Green Meshweaver, Nigma walckenaeri. All started on Saturday, during the YNU AGM in the University of Hull, where spider expert  Geoff Oxford, showed us a specimen he had just collected from the university grounds, a tiny green spider that is currently expanding its range across the UK and now colonising Yorkshire. We all admired the individual, which had been collected with its web on a leaf. 

The first Nigma walckenaeri record from Hull.

After returning from the meeting, I searched the garden ivy, and since I've been searching ivy and holly, which are favoured leaves to weave it's mesh. Nigma walckenaeri  chooses curled leaves, so it can take advantage of this to hide under its little web. As other regular character in this blog, Amaurobius, Nigma is a cribellate silk weaver. 

Today, I took a local walk and came across a magnificent mature ivy, south east facing. I started searching its leaves, wondering if I had the wrong search image in my mind. It didn't take long to find a Nigma.

Nigma walckenaeri  habitat.

There it was! A light-touch web of blueish threads with the green spider sitting, well camouflaged, underneath.

I moved part of the web aside to have a closer look (also top shot). This is a female, with her whole body green. Once I had seen one, I found another, and another, almost every ivy leaf had it's little Nigma in it. 

A male, with its brown cephalothorax.

This individual was busy weaving its web.

I even spotted a male (with reddish-brown opistosoma) on the edge of a female's web.

Until 1993 it was only found in London and the home counties, and it is associated to parks and gardens. Since then it has been steadily spreading north. I'll keep a look for it in the garden!