European Harvestman

• It is not a spider: it has neither venom glands nor silk glands, it spins no webs, and it can swallow solid particles, something no spider does.
• It practises autotomy: it sheds a leg when a predator grabs it, and the leg goes on twitching to distract the attacker. That is why they are so often seen with fewer than eight legs.
• The name Opiliones comes from the Latin opilio, shepherd, from their habit of gathering together and from the resemblance to shepherds who used stilts to watch over their flocks.
• It is not a spider. Harvestmen have a single-piece body with no waist, and produce neither silk nor venom: they build no webs and do not bite.
• Its defences are scent glands at the front of the body that secrete repellent substances, and autotomy: it sheds a leg to escape, although it does not grow back.
• Unlike spiders, it does not liquefy its prey outside the body: it tears it apart and swallows it in pieces, so it also eats plant matter and carrion.
• It is a useful predator in crops, where it eats aphids, moth eggs and mites.
• Its genome is being sequenced as a representative of the Opiliones, an order that lacked one and that is key to understanding the evolution of arachnid appendages.
• The name harvestman comes from its abundance in late summer, when the crops are brought in.

Skeleton type

Invertebrate - chitin exoskeleton (arachnid)

Habitat & environment

Very widely distributed and undemanding in its choice of habitat: it turns up almost anywhere except high mountains, from residential gardens to little-disturbed countryside

Size at birth

Spherical eggs about 0.4 mm across, dark grey or brown

Gestation / incubation

The eggs, laid in damp soil, overwinter and hatch in spring

Litter / clutch size

Around 10 eggs per clutch, with a single clutch a year

Sources consulted: Wikipedia (Phalangium opilio); EcuRed; Insectarium Virtual del Parc Natural del Penyal d'Ifac (Generalitat Valenciana); Gainett et al. 2022, Frontiers in Zoology 19; Waste Magazine

Best time: From summer to autumn, among bushes a metre off the ground and on the walls of houses