Monday 14 March 2011

Wolf spiders about

As soon as there is a sunny, mild day in March, wolf spiders come out of their hiding places and are easy to spot basking on stones or the low vegetation. In my garden, the bottom frame of the conservatory is a favourite spot (above, today). Wolf spiders (Family Lycosidae) are mainly diurnal spiders that do not build a web. It is common to see more than one, sometimes many in the same place and because they tend to move at the same time and in the same direction as they run away from you on low grass or on the ground, they were thought to hunt in "packs" therefore their name. However, they do hunt alone. They are highly visual and have three rows of eyes; the top row is made up of large eyes facing sideways, then two large forward-facing eyes, and the lower one is made of four small eyes in a line. Wolf spiders are robust and quite cryptic, typically brown with lighter and darker markings. They run fast and can even jump, but they are "sit-and-wait" hunters and they do not move much unless disturbed.
Males are in general smaller and darker than females and have dark pedipalps (above). Come May they can be seen courting females by moving in front of them, tiptoeing on their legs and waving his pedipalps to her. Fertilised females spin a pale, lentil-shaped cocoon around their eggs, and carry it around attached to their spinners. They become quite obvious now.
 Every now and then, the female repositions the cocoon, checking for humidity inside and replenishing it if necessary. Once the spiderlings are born, the female opens the cocoon and lets them crawl on her abdomen.
The "fuzzy" looking spider carries around the spiderlings until they are able to fend by themselves. Females can spin a second cocoon, and by that time males in the population have already died. There are many British species (37) and they are difficult to determine without capturing them. The ones in my garden belong to the genus Pardosa and they appear most similar to the common "spotty wolf spider", Pardosa amentata.

Websites
British Arachnological Society With checklists, gallery links to NBN gateway maps and more.
Eurospiders. Great photos and info on European spiders

1 comment:

benjaminlately said...

Is this a wolf spider or is it something else? Eyes appear to be in 2 rows rather than 3. There is some offset, but all of the eyes appear to be forward facing.
http://photography.geothunder.com/?p=329

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