Urban bush-crickets: the Speckled bush-cricket

I photographed my first Speckled Bush-cricket over 10 years ago, but it was an accidental photo of a nymph on a leaf with the insect I was actually focusing on, and I didn't actually see it at the time. Fast forward to September 2022, when I was intent on ticking this enigmatic bush-cricket from my urban insect list. I visited a brownfield site in the city outskirts where a population had been recorded, armed with a bat detector, and I quickly tuned to Speckled Bush-cricket station: 40 KHz, a similar frequency than Pipistrelle bats, the actual call a sharp 'tak' reminiscent of two stones hitting each other, repeated every few seconds. When there are more than one individual you can hear how they respond to each other, with closer, louder 'taks' followed by more distant 'taks'. In fact, in this species males and females stridulate and their calls aid them to move closer together. Now, much as hearing the calls was exciting, my challenge was to actually spot the callers, and this took a lot of patience and triangulation, but I did manage to spot and photograph this calling male.

Male Speckled Bush-cricket, Makro site, September 2022.

An early instar Speckled bush-cricket nymph, Sculcoates, 25th May 2024

Speckled bush-cricket nymphs can be seen from May onwards, they are tiny, but stunning and worth searching for: oversized antennae and head, all green with black specks all over their body, and black-stripes on their legs and antennae. Adults can be found from July to October. They are apterous, the only remaining parts of the wings are those making up the stridulatory apparatus. Males are smaller and more elongated than females, green with a brown dorsal stripe, females are all green and are stocky, with a humped appearance. The lay eggs in the bark or crevices of trees and bushes, near the ground.

Female Speckled Bush-cricket. Note the broad, up-curved ovipositor.

Behaviour. I likened Roesel's to a small toad scrambling on the grass, insetead Speckled Bush-crickets remind me of chameleons: perfectly camouflaged, perched on vegetation, still, and when they move, they do it in slow motion and in a deliberate way. 

A population of Speckled Bush-crickets thrives on neglected gardens and hedges. Brambles are a favourite plant, but they climb high on trees too.

Habitat. Speckled bush-crickets are found in a wide variety of habitats, which the common species across them being brambles: woodland edges, overgrown hedgerows or gardens, parks and brownfield sites.

Fieldcraft. Nymphs can be searched for near the ground, on nettles and bramble and other plants. An insect net can be effective on grass near brambles and nettles, but careful inspection of known sites are likely to be rewarding. Adults are much harder to find and a bat detector might help. Scan each bramble leaf, and good luck! I find this the hardest species to find and many of my records are sound recordings of the bat detector, having stared at bramble leaves for a long time. It doesn't help that adults can climb tall trees and shrubs and be found up to 14 m above ground. Using the bat detector I have unexpectedly found new colonies across the city, and it is always exciting to return the following year in spring to find the new nymphs.

There are three species of urban bush-crickets in this patch of brambles: the hardest to find is the Speckled Bush-cricket.

A male Speckled Bush cricket found with the aid of a bat detector on the edge of a local park. Note how their colour mirrors the leaf damage on brambles. Despite usually sitting on the top of leaves, they are very hard to spot.

Stowaways. Despite its flightlessness, the Speckled Bush-cricket has managed to spread from its European native range to islands like the isle of Man, Ireland and even across the Atlantic, with several populations near harbours of the US and Canada, where it most likely arrived as eggs in imported ornamental trees or bushes.