Funding: CNPq (Masters scholarship)

People: Morgana Maria Fonseca, Angelo Pallini, Arne Janssen

Description: Host plant quality (e.g., nutritional content, secondary metabolites, plant structures) is known to affect the behavior and performance of herbivores feeding on them, and consequently it also affects the natural enemies of herbivores. In biological control programs, much attention has been given to the choice of the best suited natural enemies to control agricultural pests, however, less is known about how host plant quality might affect the performance, preference, and efficacy of natural enemies. As host plants are an active part of food webs, we ask how would they affect the performance, preference and population dynamics of natural enemies, and how this affects biological control of agricultural pests.

Funding: CNPq (Doctoral scholarship)

People: Diego Bastos Silva, Jose Mauricio Simoes Bento

Description: Zoophytophagous mirids have been successfully used in biological control programs, mostly in Europe, and are commercially available. Other than through consumptive effects (i.e., direct consumption of prey), zoophytophagous predators may also benefit plants indirectly through non-consumptive effects (NCEs). NCEs are predator-mediated changes in prey behavior, morphology, and physiology. Studies on beneficial NCEs of zoophytophagous predators are mostly focused on those mediated by their phytophagy, including reduced plant attractiveness for herbivores, increased attractiveness for parasitoids, and reduced herbivore performance, although negative effects have also been reported. In this project, we looked at how NCEs may impact the use and effectiveness of mirids as biological control agents in tomato.

Funding: Western SARE

People: Tobin Northfield, Rebecca Schmidt-Jeffris, Louis Nottingham, Rick Hilton, Robert Orpet

Description: Current research indicates that earwigs are critical natural enemies of aphids, pear psylla, and codling moth. However, the role of earwigs in controlling orchard pests has been unappreciated, likely because previous pesticide programs were too harsh for earwigs to thrive. Growers that recently converted to softer programs have been unable to use earwig biological control because their populations have been eliminated; earwigs have long generation times and poor dispersal ability, which inhibits their reestablishment. This project will develop tactics that growers can use to inoculate their orchards with earwigs. Earwigs are particularly good candidates for inoculation because they are omnivorous and poor dispersers, so they often remain in orchards feeding on alternative food when pest populations are low. This contrasts with other natural enemies (e.g., ladybeetles and lacewings) that readily move out of orchards after release, especially if prey populations are low. Our main objectives are: I) to determine the best type of trap to capture earwigs where they are pests, II) if mass trapping earwigs reduce their populations over multiple seasons, and if this reduces fruit damage during harvest, III) how to integrate earwigs into an IPM program (e.g., non-target and sub-lethal effects of commonly used pesticides in tree fruit on earwigs), and finally, IV) how to better augment earwig populations in pome fruit (e.g., release rate, timing, methodology).