There are wolf spiders all over my garden, so last week I had the Ivydale School Natural History Club semaphore signalling across the classroom. There is a connection ... honest.
There are wolf spiders all over my garden, so last week I had the Ivydale School Natural History Club semaphore signalling across the classroom. There is a connection … honest.
These are great little spiders, very distinctive, unless you need to know exactly which one of our nearly 40 species are scuttling about. Rather than spinning a web to catch prey, they hunt by chasing after small insects on the soil and in the leaf litter. They get their English name from this behaviour and it was long believed they hunted in packs, like wolves. Of course, each is hunting alone, but they often appear in numbers at this time of year, scurrying across bare ground in the spring sunshine.
The ones running around my tulips are Pardosa, and although I can't decide exactly which of the 14 UK species they might be, I can tell the sex easily. The males (a specimen is pictured above) have huge palps, the long feelers (almost like short extra legs) near the head, that look like they are wearing boxing gloves.
Like all spiders, the male palps are used in the strange arachnid mating system to transfer sperm to the female. Under high-power microscope they look like bizarre pipettes, with convoluted tubes and covered with odd bumps and indentations. A male uses a palp to 'suck up' sperm deposited from the primary sexual organs and then uses it to 'inject' into the female's receiving organ, the epigyne, on the underside of her abdomen.
Almost all adult spiders can be sexed by looking at their palps, large in the male, slender in the female (pictured left). But male Pardosa palps are doubly conspicuous because they also use them for signalling to each other. Just like semaphore flags, the males wave their palps about, first one, then the other, often rocking from side to side on their legs as they do so. The males gesticulate to the females to find out whether mating is likely to be successful, or rejected.
The natural history club signalled shorter and less intrusive messages to each other. They took it in turns to spell out the middle names, which we had to guess. It was all very tricky and they thought I was joking when I spelled out …A…N…T…. It took some vigorous arm waving to finish the message …O…N…Y…above the laughter.
