Friday, 5 August 2016

Anyone for Cricket?

August is the month of the Grasshopper and Cricket. I first started to hear the orthoptrerans in the last week of July and today they were in full song. I decided to go to the racecourse where there is a large expanse of grassland.

I spent 20 minutes pacing about searching them out and had some success identifying at least 2 species, 1 Bush-Cricket and 1 Grasshopper as well as a couple of other invertebrate species.

Roesel's Bush Cricket (Metrioptera roeslli)

This is a 'relatively' new species to the area and is an indicator of a changing climate. It was originally only found on the south coast but increasing temperatures have led to the species moving steadily north. Its strident call and large size help to make it easy to see and appears now to be the dominant species in many grassland habitats in Warwick.

The species is a handsome one with a very distinctive yellow saddle on its pronotum.

The individual I was able to photograph was a female judging by its long curved ovipositor that only crickets possess. Interestingly this female was spotted just after mating, The white gel like mass is a spermatophore. Basically a packet of sperm that he deposits to the underside of the abdomen, enzymes then dissolve the skin and the sperm is released into the female to meet with the eggs. Once fertilised she will use the ovipositor to pierce grass and rush stems to lay the ovoid eggs.

Lesser Marsh Grasshopper (Chorthippus albomarginatus)

Elsewhere I found a tiny grasshopper, barely the length of my thumb nail. It had short thick antennae and a pinkish hue to it, This like the cricket is a female. It is a highly varied species with different colour morphs ranging from green to pinky purple.

An adult individual was recorded a short distance away.

Hoverfly (Chyrsotoxum verralis)

This species of hoverfly is a mimic of a wasp and it is only on close inspection is it clear that it is a fly and not a wasp. The key identification feature in this case is the fly like eyes that are very different to those of a wasp.

Here is a a common wasp (Vespa vulgaris) taken on a different day to compare

Spined Mason Bee (Osmia spinulosa)

This is a species I have never recorded before, Its a handsome little bee with a distinctive fringe of yellow hairs around an otherwise black body. They have a fascinating life cycle, choosing to nest in empty snail shells.

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