The wasp is a parasitoid that attacks diamondback moth larvae and recently abundant in some fields in 2017. In some of the fields sampled, as many parasitoids as cabbage seedpod weevil (i.e., nearly one per sweep) were observed. In the fields sampled (i.e., around 10), cabbage seedpod weevils were below thresholds on average, though some spots may have been close to the threshold of 2-3 weevils per sweep.
The above observation emphasizes the value of beneficial arthropods like Diolcogaster claritibia. It is important to recognize that foliar applications of insecticides kill beneficial insects like this small wasp (about 2 mm) which attacks and helps regulate pest populations of diamondback moth or other Lepidoptera, including cutworms and cabbage worms. Thus, think beneficials before you spray!
|Figure 1. Diolcagaster claritibia adult measuring ~2mm in length (Photo credit J. Fernandez, AAFC-Ottawa).|
Learn more about beneficials by accessing Field Heroes and all the Blog's Parasitoid posts.