Two unidentified harvestmen photographed on the Plants for Bugs
experimental beds at Wisley.
Harvestmen lack the venomous fangs that spiders use to subdue their prey. Harvestmen will catch and eat some small invertebrates but they also feed as scavengers on dead invertebrates, excrement and overripe fruits. Some species, such as Anelasmocephalus cambridgei, prey on snails. Harvestmen mostly live at ground level but some species, such as Leiobunum rotundatum and Paroligolophus agrestis will climb walls and trees.
Harvestmen are mainly nocturnal and during the day often rest in shaded places. When disturbed they will run away or remain stationary and bounce their bodies rapidly up and down. Resting harvestman are often encountered aggregated together, sometimes in large numbers. This short Youtube video here
shows a small aggregation, and if you look carefully you can see body bouncing.
After mating, females deposit eggs in the soil or under loose bark. The eggs hatch into small versions of the adult animals. The developing harvestmen shed their outer skin on several occasions as they increase in size. Many species become adult in late summer, which coincides with harvest time and this is thought to be the derivation of their common name.
Role of harvestmen in gardens
Harvestmen are part of a healthy garden ecosystem. They cause no damage to plants, but are not especially useful in terms of preying on potential garden pests. As a group they are relatively unstudied, and studying them in your garden could contribute really interesting new information.
of the British Arachnological Society wbsite http://wiki.britishspiders.org.uk/
Natural History Museum checklist
of harvestmen of the British Isles
Hillyard, P. D. (2005) Synopses of the British Fauna, vol. 4, Harvestmen. Linnean Society
Page text drafted by Andrew Halstead, reviewed by Andrew Salisbury, compiled by Steve Head