Saturday 10 October 2015

Lycosidae: wolf spiders

There are 37 British species belonging to this family. Lycosids or wolf spiders are medium to large species that are usually found running on the ground, although are burrow dwellers and others live near water, and can dive for safety. They are highly visual spiders, and have a pair of large eyes and then two small pairs in a row underneath and two middle sized ones on the side of the head. Most species are active during the day, with a strong tendency to bask in sunny spots in the open, often in large numbers in some species. When resting they fold their front legs underneath their body, and leave the rear legs stretched. When disturbed they can quickly run, even jump, for cover. They can be remarkably camouflaged in their habitats.

Wolf Spiders typically mature in the spring. Adult males spend much of their time finding and courting females. They might locate the female first using pheromones, but the courtship display uses mainly visual cues. Male palps or front lets tend to be dark and males will wave them up and down alternatively, vibrating the palps and abdomen in front of females, legs stretched as in tiptoes, approaching a little bit in between signals. Females may accept the male by tapping their front legs rapidly on the ground, however they often retreat, or lunge at the males to scare them off. This rarely deters the insistent male for long. Read this post in BugBlog for more on the courtship of these spiders.

Mature male Pardosa sp. on the look out for females
A male courting an egg carrying female

Egg sacs and spiderling piggy backs
Their wandering nature has resulting on wolf spiders unique way to carry their egg sacs and their young. Females wrap their eggs in lentil shaped egg sacs that they secure to their spinnerets and carry with them for a couple of weeks. The female opens the egg sac to allow the spiderlings to emerge. Once they do, they climb onto their mothers abdomen and are so carried for several days.
Pardosa, likely amentata, a common species in my garden.
This is the bluest eggs sac I've seen on a Pardosa female. Possibly freshly made?
Pardosa female with her spiderlings

A wolf spider gallery
This family, as many other spider families, contains many species that are difficult to identify in the field. If you see any obvious identification mistakes please let me know.
Arctosa perita, an amazingly camouflaged species on sandy beaches and dunes (also top shot). This one photographed at Spurn Point yesterday. This species makes a silk lined burrow where she spends much of her time (read this post from Catherine Scott's blog with fantastic photos of this species and the burrows they make).
Possibly Pardosa pullata, female with egg sac, on rocky mountainside
Female Pardosa possibly amentata with egg sac, basking in the garden.
Unidentified wolf spider with spiderlings on mossy, heathland area.
Trochosa sp. on pond margin.
A Pirata piraticus, pirate wolf spider, resting on the water surface. This spider can be found on ponds and they often run across the surface, where they hunt small invertebrates.
The striking male Pardosa lugubris/saltans
Female Pardosa lugubris/saltans with egg sac

1 comment:

Anonymous said...

Female wolf spiders as many other spiders display maternal behaviour. First, they carry their eggs wrapped in a silky egg sac until their spiderlings emerge. As these spiders move about in search of prey, this offers more protection to their eggs from casual predators than if the egg sac was attached somewhere and left on its own.
More Info are wolf spiders poisonous to humans