The USDA Cranberry Entomology Lab: Highlights from 2011-2016

Abstract: Biological, chemical, and cultural control methods have been investigated as part of the cranberry crop protection program pursued in the USDA Cranberry Entomology Laboratory. Surveys of native entomopathogenic nematodes in Wisconsin have produced a new bio-insecticide agent (Oscheius onirici subsp. wisconsinensis), which shows high virulence against flea beetles, cranberry fruitworm, and sparganothis fruitworm. Other biological control studies have examined spider densities in flooded vs. sprayed cranberry beds, showing that flooding conserves hyper-abundant beneficial arthropod populations, such as spiders and springtails. Flooding also appears to directly reduce populations of black-headed fireworm and sparganothis fruitworm, while having no negative impact on the harvestable crop. Investigations of temperature-mediated development of sparganothis and cranberry fruitworm larvae have provided key “spray windows,” allowing for greater precision in insecticide use. Other chemical control work has involved the deployment of a multi-species mating disruption (MD) program for cranberries. Early evidence suggested that black-headed fireworm and cranberry fruitworm mating can be significantly reduced using a paraffin emulsion carrier, and importantly, berry infestation rates can be reduced below that of insecticides alone. The mechanization of MD deployment has involved the creation of novel extrusion devices, which have been successfully mounted on drones as well as boom-arm sprayers. Protection of the cranberry crop requires conservation of cranberry pollinators, and recent studies of native bee species have revealed that fungicides indirectly compromise larval bee health by suppressing certain fungi within fermenting pollen-provisions. Ongoing work will investigate the nature and magnitude of fungicide impacts on bee-microbe symbioses