Improving the biocontrol potential of entomopathogenic nematodes against Mamestra brassicae : effect of spray application technique, adjuvants and an attractant

BACKGROUND:SteinernemacarpocapsaeWeiser,anentomopathogenicnematode(EPN),isapotentialbiologicalcontrolagent for the cabbage moth (Mamestra brassicae L.). This research aimed to identify a suitable spray application technique, and to determinewhetheryeast extractaddedtoanEPN sprayhas anattractingand/orafeedingstimulanteffectonM.brassicae.The biological control capabilities of EPN against this pest were examined in the field. RESULTS: Good coverage of the underside of cauliflower leaves, the habitat of young instar larvae (L1‐L4) of M. brassicae was obtainedusingdifferentsprayboomconfigurationswithverticalextensionsthatcarriedunderleafsprayingnozzles.Oneofthe configurations was selected for field testing with an EPN spray. Brewer’s yeast extract stimulated larval feeding on leaves, and increasedthemortalityoftheselarvaewhenexposedtoEPN.ThefieldtrialshowedthatasprayapplicationwithS.carpocapsae, Addit and xanthan gum can effectively lower the numbers of cabbage heads damaged by M. brassicae. Brewer’s yeast extract did not significantly increase this field performance of EPN. CONCLUSION: Steinernema carpocapsae, applied with an appropriate spray technique, can be used within biological control schemes as part of a resistance management programme for Bt. c � 2013 Society of Chemical Industry