Participatory research in sustainable agriculture: Peach twig borer, Anarsia lineatella Zeller, biology and natural biological control by Formica aerata (Francoeur) in California peach agroecosystems

Participatory research strategies were used to conduct insect pest management research in peach agroecosystems in the Central Valley of California. A theoretical and philosophical framework constructed from contemporary work in the philosophy and sociology of science provided the foundation for the application of participatory research in the context of US sustainable agriculture. Methodologies modified from Rapid Rural Appraisal were used to collaborate with members of the community based farmer organization, California Clean Growers Association (CCGA). Farmers identified peach twig borer (PTB), Anarsia lineatella Zeller (Lepidoptera: Gelechiidae) as their most important insect pest and participated in developing, implementing, and revising research directed toward understanding PTB biology and ecology to improve cultural and natural biological control based management practices.; PTB stage specific development and ovipositional behavior were investigated utilizing a recently established laboratory colony. Results are presented for the effects of diet on larval and pupal development and survivorship. Egg, larval, pupal, and preoviposition developmental times were estimated from laboratory reared individuals. A method to determine the age of laboratory reared instars based on head capsule width is given. Oviposition choice and no-choice experiments were used to demonstrate that the presence of peach fruit significantly increased age specific and total fecundity and influenced egg placement. These results provided background information and source material to pursue on-farm research on biotic and abiotic sources of PTB mortality.; The impact of generalist predators on regulating PTB was assessed through predator exclusion-experiments conducted at on-farm sites. Results were used to construct partial life tables which indicated that predation by the native ant, Formica aerata (Francoeur), was the most important stage specific mortality agent for overwintering and first generation larvae. The impact of other generalists predators on larval survival in these generations was negligible. F. aerata foragers were frequent visitors at peach leaf extrafloral nectaries. Experimental results indicated that F. aerata predation reduced larval survival, suggesting that the ant-plant interaction is a case of facultative mutualism resulting in PTB natural biological control.