Order Opiliones: The Harvestmen

We are not talking about farmers who bring in the crops at the end of the season, but about harvest spiders, also known as daddy-longlegs. Harvestmen are often confused with spiders because of their extraordinary long legs. Although distantly related to spiders, the harvestmen are quite a distinct and ancient group, and when looking more closely at a harvestman, aside from having long legs like some spiders, but which are much thinner and spindly, the head and thorax (cephalothorax in spiders) is broadly fused together with the abdomen, and they have two eyes instead of eight. The eyes of a harvestman are usually placed centrally on a tubercule and look sideways. This is called an ocular tubercule or ocularium, and it often contains two rows of spines and teeth.

Harvestmen have no silk glands or spinners, so do not produce webs or strands of silk as spiders do. They also lack venom or poison glands.They are mainly nocturnal creatures, and they feed on a variety of invertebrates, including insects, worms, woodlice, small snails, other arachnids including other harvestmen.

Harvestmen are considered to be the traditional gardener’s friend as they help to keep pest populations down. They may also eat dead organisms and fecal material, like bird droppings, and feed on fungi, fruit and vegetation. Some harvestmen have short legs, whilst other are very long which enables them to move quickly and nimbly when hunting or avoiding prey. As a defensive measure, they have a pair of prosomatic scent glands which secretes an unpleasant odour when disturbed or threatened. When the legs of harvestmen become detached they can continue to move, twitching for a length of time, which maybe a way of distracting a predator so the harvestman may make good its escape.

Family Sclerosomatidae

Leiobunum rotundum
Leiobunum rotundum – female
Leiobunum blackwalli
Leiobunum blackwalli – male

Family Phalangiidae

Dicranopalpus ramosus agg. - female
Dicranopalpus ramosus agg. – female
Opilio canestrinii female
Opilio canestrinii
Dicranopalpus ramosus agg. - male
Dicranopalpus ramosus agg. – male
Odiellus spinosus
Odiellus spinosus