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ARS Home » Northeast Area » Kearneysville, West Virginia » Appalachian Fruit Research Laboratory » Innovative Fruit Production, Improvement, and Protection » Research » Publications at this Location » Publication #193944
Title: COMPARATIVE SURVIVAL RATES OF ORIENTAL FRUIT MOTH (LEPIDOPTERA: TORTRICIDAE) LARVAE ON SHOOTS AND FRUIT OF APPLE AND PEACH

Author
item Myers, Clayton
item HULL, LARRY - PENN STATE UNIVERSITY
item KRAWCZYK, GRZEGORZ - PENN STATE UNIVERSITY

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/10/2006
Publication Date: 8/1/2006
Citation: Myers, C.T., Hull, L.A., Krawczyk, G. 2006. Comparative survival rates of oriental fruit moth (lepidoptera: tortricidae) larvae on shoots and fruit of apple and peach. Journal of Economic Entomology. 99: 1299-1309.

Interpretive Summary: Oriental fruit moth (OFM) has emerged as a very destructive pest problem on apples in the eastern United States since about 1998. The reasons for the sudden outbreaks are unknown, but one major hypothesis is that OFM exhibit different biology and behavior on different host plants. These experiments investigated how larval survival differed between peach and apple hosts. On growing shoots, where OFM feeds during the early season, larval survival is very comparable between peach and apple. However, on peach, larvae tend to utilize multiple shoots, while on apple, larvae tend to remain in one shoot for their entire development. This means that larvae are not exposed to insecticide residues as much on apple because they tend to remain inside a single shoot rather than feeding on multiple shoots. On fruit, maturity of fruit is the best predictor of larval survival. Larvae tend to due better on ripe peaches than on unripe apples, and thus total larval survival may be higher in both peach and apple as the crops approach harvest, meaning that control of OFM near harvest is very critical. Larval survival varied somewhat in apples by fruit cultivar, with ‘Rome Beauty’ appearing to be a less suitable host than some other commercial cultivars. Understanding cultivar variation in survival may help growers to prioritize OFM control efforts in mixed cultivar blocks and also to adopt cultivar-specific action thresholds for treating OFM outbreaks.

Technical Abstract: Studies were designed to examine the effects of host plants on oriental fruit moth, Grapholita molesta (Busck) survival. G. molesta larval survival in the orchard was comparable between apple and peach shoots, indicating that both host species can harbor large larval populations during the early season. G. molesta larvae utilized multiple shoots for feeding and development on peaches but usually only damaged single shoots in apple. Survival differences were present between peach and apple fruit, but this was affected by fruit maturity level. Generally, larval survival higher was in ripening peach fruit than in green, immature apple fruit. Larval survival varied among several apple cultivars, indicating that cultivar-level variability needs to be considered. These host-associated effects may impact efforts to predictively model G. molesta populations in commercial orchards where multiple host plant species, or different cultivars of the same species are often grown in close proximity. Thus, host-associated dynamics should be included into future population models that underlie management programs.