Cabbage moth update February 2016

Telenomus sp. has been found to efficiently parasitize eggs of the cabbage moth (Mamestra brassicae) under laboratory and field conditions. However its abundance in nature is relatively low with the highest parasitation rate measured around 10%. At date the only efficient way to prevent the spread of the cabbage moth is through the application of broad spectrum insecticides, killing also non-target insects. Therefore there is the need of sustainable alternative solutions. The development of a new biological control product based on the egg parasitoid Telenomus sp. represents such an alternative.

Field trials

After gaining, during the first year of the BIOCOMES project, information on the biology of this parasitoid, in the second year we conducted the first field trials with releases of the biological control agent (BCA). In a plot trial we tested two BCA densities against plots with no BCA release. In collaboration with Andermatt Biocontrol AG we also developed a suitable field delivery system to efficiently release the BCA in the field.

Collecting egg parasitoid samples

The results show a significant increase in the parasitation rate after BCA release, although no difference was found between plots with and without BCA release. This is probably due the high amount of parasitoids released. In addition to these first efficacy trials we also exposed trap eggs in Spain, Italy and Sweden with the intent to collect and describe Telenomus sp. in these countries. To further investigate the distribution of this parasitoid we are also collaborating with different researchers in Europe, that are sending us egg parasitoid samples. The insects will be determined at the species level using molecular and morphological tools.

See our earlier update on the cabbage moth research:

Read more about our activities on cabbage moth

Picture: Exposition of trap eggs (Mamestra brassicae) on white cabbage plants to monitor the parasitation rate of the biological control agent. (Picture FiBL, Switzerland)

Author

Lucius Tamm
Lucius Tamm
Cabbage moth
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