THE OTHER DADDY-LONG-LEGS
Autumn is the prime time for a very common and numerous, but little known, group of spider-like animals called harvestmen. In Britain there are about two dozen species of these otherwise mainly tropical creatures of which there may be 10,000 species worldwide. They are close cousins to spiders (with several hundred species in Britain) for which they are often mistaken. Harvestmen though lack the poison glands and silk-making ability of spiders, and are probably more closely related to mites and scorpions. The average garden or park will probably be home to nine or ten species, a higher than average proportion of the total number of species in this country when compared to other groups.
Harvestmen are remarkable creatures. Like spiders they have eight legs and in many species these are very long and thin, perhaps the longest legs in relation to their bodies of any other animals. The second pair is always the longest and act as sensory organs as well as being used for walking. They seem to perform the same functions as antennae do in insects, with harvestmen constantly waving them and using them to probe the ground ahead. Their small and round one-piece bodies are suspended above the ground by the legs, and are often topped by a turret-like appendage called an ocularium. This carries two outward facing eyes. Here is another difference to spiders, which have six or eight eyes. Overall many harvestmen look like miniature monsters from science fiction.
Those long thin legs are easily and frequently lost, but they do not regrow. When a harvestman loses one whilst being attacked by a predator the detached leg continues to move and jerk about, thus acting as a decoy whilst the harvestman limps away.
Harvestmen are nocturnal hunters and scavengers. They eat almost any animal and vegetable matter, alive or dead, including bird droppings. During the day they rest in leaf litter, grass and other plants or on trees and walls. They prefer shady places, so may be found beneath window sills or in deep cracks in bark. When disturbed they move surprisingly quickly considering their ungainly appearance.
The name 'harvestman' arises from the huge numbers of these creatures found at this time of the year. Because of their habit of sheltering in grasses and other plants many of them were disturbed during hay-making and harvesting. They are also sometimes referred to as 'daddy-long-legs', although that epithet really belongs to crane flies, which are also prominent in late summer and autumn. If you disturb a 'spider' whilst gardening at this time of the year take a closer look - the chances are you have roused a sleepy harvestman.