title: Exposure to Guava Affects Citrus Olfactory Cues and Attractiveness to Diaphorina citri (Hemiptera: Psyllidae).
abstract: Intercropping can reduce agricultural pest incidence, and represents an important sustainable alternative to conventional pest control methods. Understanding the ecological mechanisms for intercropping could help optimize its use, particularly in tropical systems which present a large number of intercropping possibilities. Citrus is threatened worldwide by greening disease (huanglongbing, HLB) vectored by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae). Control of HLB and citrus psyllid can be partially achieved through intercropping with guava, Psidium guajava L., but the mechanisms remain unclear. We tested the hypothesis that guava olfactory cues affect psyllid behavior by altering the attractiveness of citrus through plant-plant interactions. In choice and no-choice cage experiments, psyllid settlement was reduced on citrus shoots that had been exposed to guava shoot odors for at least 2 h. In Y-tube olfactometer experiments, psyllids oriented to odors of unexposed, compared with guava-exposed, citrus shoots. These behavioral results indicate that a mechanism for the success of guava intercropping for sustainable, ecological disease management may be the indirect effect of guava on citrus attractiveness.
authors.affiliation: Key Laboratory of Natural Pesticide and Chemical Biology of the Ministry of Education, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, Guangdong, China (barmansso@yahoo.com; zengxn@scau.edu.cn), zengxn@scau.edu.cn.
authors.forename: Jagadish Chandra
authors.initials: JC
authors.lastname: Barman
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks St., Toronto, Ontario, Canada (sa.campbell@utoronto.ca).
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Campbell
authors.affiliation: Key Laboratory of Natural Pesticide and Chemical Biology of the Ministry of Education, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, Guangdong, China (barmansso@yahoo.com; zengxn@scau.edu.cn), zengxn@scau.edu.cn.
authors.forename: Xinnian
authors.initials: X
authors.lastname: Zeng
mesh_terms: D000818:Animals; D002681:China; D002957:Citrus / Q000378:metabolism*; D000069599:Crop Production; D005247:Feeding Behavior / Q000187:drug effects; D005260:Female; D006430:Hemiptera / Q000187:drug effects / Q000502:physiology*; D008297:Male; D010572:Pest Control, Biological; D010675:Pheromones / Q000378:metabolism / Q000494:pharmacology; D031647:Psidium / Q000737:chemistry* / Q000378:metabolism; D012903:Smell
chemical_list: D010675:Pheromones; C010411:insect attractants
keywords: Diaphorina citri; Psidium guajava; olfactory cue; plant–insect interaction; plant–plant interaction