What is the difference between predators and parasitoids
Predators eat many prey during their development. Examples include ladybird beetles, predatory mites and lacewings. In the intriguing world of beneficial insects, parasitoids are almost exclusively tiny, highly specialised wasps.
If you are wondering about the difference between a parasitoid and a parasite, the former kills its prey during development. For example, the tiny wasp parasitoid Aphidius colemani consumes its aphid prey from within the mummified body of the pest insect before emerging as an adult wasp to mate and continue the cycle. Parasites (e.g. mosquitoes, tapeworms etc) feed exclusively on another organism, generally without causing death of the host.
Eretmocerus hayati – a highly specialised parasitoid wasp that completes most of its life cycle in silver leaf whitefly
(photo by Denis Crawford, Graphic Science)
So how do we decide whether to use parasitoids or predators?
Parasitoids offer the advantage that they can be incredibly efficient against their natural host, but the disadvantage that they are invariably more specialised with a limited host range. Some parasitoids are so uniquely adapted that they only develop in one species of host insect.
Predators, on the other hand, usually display a greater range of food preference, often feeding on many different pest species.
As always there are exceptions to the above general principles, but if you are sure you know the pest you are dealing with, and there is a specific parasitoid available, that is usually the preferred option.
Our biocontrol agents are compatible with each other. The more different species you have working for you the better – so no harm in a ‘mix and match’ approach to achieve the best outcome.
The spotted ladybird is a true predator. It feeds on most species of aphids and will even have a feast on psyllids.
Lacewings are very much a generalist predator and will attack pretty much any soft bodied insect that gets in its way.
