Thursday 22 October 2015

Sparassidae: huntsman spiders

Photo credit: Ettore Balocchi, CC BY 2.0, via Flickr
A family of over 1000 species, mainly found in warm regions. There is just one British species, Micrommata virescens, the Green Huntsman, a large, and vividly green spider unlikely to be confused with any other. While females are all green (above), males are also marked with red stripes alongside the abdomen. Its eight eyes are arranged in an oval pattern and are surrounded by white hairs like eyelashes. This spider lives in damp woodland clearings and rides, where it can be found on the lower branches of trees, oak saplings and grass tussocks. It's mainly diurnal and it does not build a web, instead relying on its camouflage: sitting head down waiting for prey to come near.
The Green Huntsman is an uncommon and local spider, mainly found in the south of England (click here for a distribution map) and it also appears to be in decline. As it grows relatively slowly, taking 18 months to reach maturity, populations may be adversely affected by cold and wet springs.

No courtship, long copulation
Males mature in May and June and have a very short season. They grab females if they find them, with no preliminaries, but copulation is long.

Leaf huts
When ready to lay, the female locks herself  in a large leaf retreat made by attaching together and lining several leaves with silk. She wraps her green eggs on a whitish egg sac, and remains in this retreat until the spiderlings disperse. A second brood may be produced.

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