Discovery could help pest control
A species of parasitic wasp discovered by chance could provide growers with a chemical-free way of controlling a major pest.
The discovery came when the wasps appeared mysteriously in colonies of cabbage stem flea beetles being studied to test feeding preferences on oilseed rape.
The wasps appeared even though the beetles were confined to potted oilseed rape plants inside micro-perforated bags.
A study carried out by researchers at the John Innes Centre is the first English published description of this parasitoid of the adult CSFB. Experiments showed that within controlled conditions the presence of wasps in sufficient numbers led to the collapse of the beetle colonies.
Beetle hosts are rendered sterile and die after the wasp larvae emerge from the body after passing through its digestive system.
The wasp is an obscure species called Microctonus brassicae. The beetle has become a prominent pest in the UK.
Something that was initially very annoying leading to the collapse of our research colonies has turned out to be fortunate.
It offers the possibility of using parasitoid wasps as bio-controls for farmers and growers of oilseed rape and brassica vegetables against cabbage stem flea beetle as part of an integrated pest management approach.
Dr Rachel Wells of the John Innes Centre
