Beneficials on farmland: identification and management guidelines (HGCA Summer 2008)

Other beneficials

Invertebrates (eg mites, springtails and earthworms) that break down organic matter are sometimes referred to as detritivores. These play a vital role in incorporating organic matter in soil to maintain fertility and structure.

Species that feed on organic matter tend to be less active than predatory species and occur in very large numbers in soil.

Springtails (Collembola)

There are some 300 British species. Springtails are small wingless insects, usually found in soil, leaf litter and vegetation. They have a cylindrical, or globular, body shape and are rarely over 5mm long. They usually have a forked springing organ which enables them to leap into the air when disturbed.


Orchesella cincta

Earthworms

There are about 24 species in Britain. Earthworms play a major role in breaking down organic matter and recycling nutrients. They improve soil structure by forming aggregates and improving conditions for plant growth.


30–350mm depends on species


Lumbricus spp

Woodlice

Woodlice differ from insects and mites in having seven pairs of legs. Most live only in moist habitats. Most are beneficial, feeding on organic matter and accelerating nutrient return to soil, but they may damage seedlings.



Oniscus asellus

Centipedes and millipedes

These are not insects but belong to the myriapoda, meaning “many legs”. They have a variable, always odd, number of flattened segments.

Centipedes have one pair of legs on each segment. They are fast moving and mainly predatory.

Millipedes have two legs on each segment and are slow moving. They feed on live and dead plant material and can occasionally damage seeds, tubers and bulbs.



Centipede

Millipede

Mites (Acarids)

Mites have eight legs (larval stages sometimes have fewer). Like harvestmen, they have a single main body segment. They are at most a few millimetres long and are not easily seen.

One group of mites, the mesostigmata, are predators of thrips, other pest mites and small invertebrates.



Dinothrombium spp

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