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ARS Home » Pacific West Area » Wapato, Washington » Temperate Tree Fruit and Vegetable Research » Research » Publications at this Location » Publication #177892

Title: OPTIMIZING THE USE OF THE CODLING MOTH GRANULOVIRUS: EFFECTS OF APPLICATION RATE AND SPRAYING FREQUENCY ON CONTROL OF CODLING MOTH LARVAE IN PACIFIC NORTHWEST APPLE ORCHARDS

Author
item Arthurs, Steven
item Lacey, Lawrence
item FRITTS, R. - CERTIS USA

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/10/2005
Publication Date: 10/2/2005
Citation: Arthurs, S.P., Lacey, L.A., Fritts, R. 2005. Optimizing the use of the codling moth granulovirus: effects of application rate and spraying frequency on control of codling moth larvae in pacific northwest apple orchards. J. Econ. Entomol. 98:1459-1468.

Interpretive Summary: Codling moth is the most serious insect pest of apple in the Pacific Northwest. The traditional method for controlling this pest is through the routine application of broad spectrum insecticides. Options for codling moth control for organic growers has been limited to oils, trapping, mating disruption, manual removal of infested fruit and the like. The recent registration of 3 commercial formulations of the codling moth granulovirus (CpGV) in the USA and their approval by the Organic Materials Review Institute (OMRI) expands the option for control of neonate larvae in organic orchards. It also provides conventional growers with an additional treatment. Among the biological control options available for codling moth, CpGV provides effective and selective control of neonate larvae. Researchers at the USDA-ARS Laboratory in Wapato, WA have investigated conditions for optimizing the effect of the virus on codling moth. Their results indicate that 3 oz of virus per acre applied at 7 to 10 day intervals when hatching larvae are present will control the moth and demonstrate an important new technology for apple and pear growers. The specificity of the virus for codling moth and safety for non-target organisms has been very thoroughly documented. Its use will contribute significantly to the conservation of other natural enemies in the orchard agroecosystem. Given its virulence and specificity to codling moth, CpGV provides an important intervention for inclusion in pest management programs in pome fruit and walnuts. This microbial control agent will enhance and complement the control activity provided by mating disruption.

Technical Abstract: Applications of the codling moth granulovirus (CpGV), which target neonate larvae before or during initial entry into fruit, offer potential for selective control of this key pest. Current recommendations call for regular applications of the virus throughout the codling moth season, making it more expensive (labor/cost) compared with some alternatives. In 2004 field tests on apple we compared the effectiveness of different application strategies of the virus. In experimental plots with single tree replicates, percent of fruit damage was not reduced by virus applications although the depth of entries and proportion of larvae killed (assessed at the end of the first generation and at harvest) were dependent on the virus dose and application frequency. In commercial orchard, ½ acre replicated blocks were treated weekly with a standard and reduced rates of the virus. This trial showed similar results compared with the experimental blocks, although fruit damage was reduced at a standard rate (not as much as Guthion) and larval mortality was slightly lower in the second generation.