title: Isolation and identification of host cues from mango, Mangifera indica, that attract gravid female oriental fruit fly, Bactrocera dorsalis.
abstract: The oriental fruit fly, Bactrocera dorsalis, is an economically damaging, polyphagous pest of fruit crops in South-East Asia and Hawaii, and a quarantine pest in other parts of the world. The objective of our study was to identify new attractants for B. dorsalis from overripe mango fruits. Headspace samples of volatiles were collected from two cultivars of mango, 'Alphonso' and 'Chausa', and a strong positive behavioral response was observed when female B. dorsalis were exposed to these volatiles in olfactometer bioassays. Coupled GC-EAG with female B. dorsalis revealed 7 compounds from 'Alphonso' headspace and 15 compounds from 'Chausa' headspace that elicited an EAG response. The EAG-active compounds, from 'Alphonso', were identified, using GC-MS, as heptane, myrcene, (Z)-ocimene, (E)-ocimene, allo-ocimene, (Z)-myroxide, and γ-octalactone, with the two ocimene isomers being the dominant compounds. The EAG-active compounds from 'Chausa' were 3-hydroxy-2-butanone, 3-methyl-1-butanol, ethyl butanoate, ethyl methacrylate, ethyl crotonate, ethyl tiglate, 1-octen-3-ol, ethyl hexanoate, 3-carene, p-cymene, ethyl sorbate, α-terpinolene, phenyl ethyl alcohol, ethyl octanoate, and benzothiazole. Individual compounds were significantly attractive when a standard dose (1 μg on filter paper) was tested in the olfactometer. Furthermore, synthetic blends with the same concentration and ratio of compounds as in the natural headspace samples were highly attractive (P < 0.001), and in a choice test, fruit flies did not show any preference for the natural samples over the synthetic blends. Results are discussed in relation to developing a lure for female B. dorsalis to bait traps with.
authors.affiliation: Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK.
authors.forename: Pagadala D Kamala
authors.initials: PD
authors.lastname: Jayanthi
authors.forename: Christine M
authors.initials: CM
authors.lastname: Woodcock
authors.forename: John
authors.initials: J
authors.lastname: Caulfield
authors.forename: Michael A
authors.initials: MA
authors.lastname: Birkett
authors.forename: Toby J A
authors.initials: TJ
authors.lastname: Bruce
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003463:Cues; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D031022:Mangifera / Q000737:chemistry*; D010675:Pheromones / Q000032:analysis / Q000302:isolation & purification* / Q000494:pharmacology*; D033621:Tephritidae / Q000187:drug effects*
chemical_list: D010675:Pheromones