Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/3/2007
Publication Date: 2/20/2007
Citation: Arthurs, S.P., Lacey, L.A., Miliczky, E. 2007. Evaluation of the codling mont granulovirus and spinosad for codling moth control and impact on non-target species in pear orchards. Biological Control 41:99-109. Interpretive Summary: Codling moth is a serious insect pest of apple and pear in the Pacific Northwest. It is most commonly controlled using broad-spectrum chemical insecticides. Options for controlling codling moth in organic orchards or orchards adopting environmentally friendly strategies are limited. The recent registration of commercial formulations of the codling moth granulovirus (CpGV) and another reduced risk chemical pesticide (spinosad) in the USA and the approval of some insecticidal formulations by the Organic Materials Review Institute (OMNRI) expand options for control of codling moth in organic orchards. They also provide conventional growers with pest control methods that can be used close to salmon breeding habitats or close to harvest, and to forestall insecticide resistance. Entomologists at the USDA-ARS Yakima Agricultural Research Laboratory evaluated organically approved CpGV and spinosad formulations in experimental and commercial pear orchards. Results showed that both products were effective for controlling codling moth in the orchard, although spinosad was more effective at protecting fruit from damage. Spinosad but not CpGV was slightly harmful to certain beneficial or non-target species, although neither product (used alone or in combination) led to increased secondary pest problems in the orchard. Both CpGV and spinosad are viable alternatives for control of codling moth in this region.
Technical Abstract: The coding moth is a key insect pest of apple and pear in the Pacific Northwest. Insecticidal formulations of the codling moth granulovirus (CpGV) and spinosad that are approved for use in both organic and conventionally managed orchards have recently become available. In tests in experimental and commercial pear orchards, we compared these two products in terms of effectiveness for codling moth control and safety to non-target organisms, including beneficial species that control codling moth and other orchard pests. Our data showed that spinosad was effective at protecting fruit, e.g. '1.6% codling moth injury in experimental blocks, compared with up to 37% injury in the untreated blocks at harvest over two years. CpGV was less effective than spinosad at preventing fruit damage, but killed the majority (67-71%) of coding moth larvae that reached the fruit and did not harm non-target species. Spinosad was safe for several predators, notably the psylla predator Deraeocoris brevis Uhler, but reduced the abundance of parasitic wasps that attack orchard pests by 24% and 40% and non-target flies by 49% and 35% respectively in experimental plots over two consecutive seasons. We found no evidence that spinosad disrupted natural pest control, leading to increased numbers of secondary orchard pests including aphids and mites in either experimental or commercial orchards. Our results show CpGV and spinosad are effective and compatible with integrated pest management for codling moth in the region.