title: Semiochemistry of the goldeneyed lacewing Chrysopa oculata: attraction of males to a male-produced pheromone.
abstract: Gas chromatographic-electroantennographic detection (G3C-EAD) experiments showed that antennae of males and females of the goldeneyed lacewing, Chrysopa oculata Say (Co. = Chrysopa), consistently responded to four compounds extracted from the abdominal cuticle of males:nonanal, nonanol, nonanoic acid, and (1R*,2S*,5R*,8R*)-iridodial. These compounds were not detected from abdominal cuticle of females. Thoracic extracts of both sexes contained antennal-stimulatory 1-tridecene and EAD-inactive skatole. Chrysopa oculata adults were most sensitive to (1R,2S,5R,8R)-iridodial standard at an EAD-response threshold between 0.1 and 1 pg, which was 10-100 times lower than thresholds for nonanal and nonanoic acid, and up to 10,000 times lower than thresholds for other compounds tested. A similar EAD response pattern was also found in another Chrysopa sp. (Co. quadripunctata Burmeister). In field-trapping experiments, (1R,2S,5R,8R)-iridodial was the only male-specific compound that attracted Co. oculata males. Males also were weakly attracted to (1R,4aS,7S,7aR)-nepetalactol (an aphid sex pheromone component), probably due to the 5% (1R,2S,5R,8R)-iridodial present in the synthetic sample as an impurity. A herbivore-induced plant volatile, methyl salicylate, increased attraction of males to (1R,2S,5R,8R)-iridodial, whereas 1-tridecene was antagonistic. No females were caught in the entire study. Scanning electron micrographs revealed numerous male-specific, elliptical epidermal glands on the 3rd-8th abdominal sternites of Co. oculata, which are likely the pheromone glands. Another lacewing species, Chrysoperla rufilabris (Burmeister) (Cl. = Chrysoperla), did not produce male-specific volatiles or possess the type of gland presumed to produce pheromone in Co. oculata males, but (Z)-4-tridecene was identified as a major antennal-stimulatory compound from thoracic extracts of both sexes of Cl. rufilabris. Thus, (1R,2S,5R,8R)-iridodial (or its enantiomer) is now identified as a male-produced male aggregation pheromone for Co. oculata, the first pheromone identified for lacewings.
authors.affiliation: USDA-ARS Chemicals Affecting Insect Behavior Laboratory, B-007 BARC-West ,Beltsville, Maryland 20705, USA.
authors.forename: Qing-He
authors.initials: QH
authors.lastname: Zhang
authors.forename: Kamlesh R
authors.initials: KR
authors.lastname: Chauhan
authors.forename: Eric F
authors.initials: EF
authors.lastname: Erbe
authors.forename: Ajay R
authors.initials: AR
authors.lastname: Vellore
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Aldrich
mesh_terms: D000447:Aldehydes / Q000737:chemistry / Q000494:pharmacology; D000473:Alkanes / Q000737:chemistry / Q000494:pharmacology; D000475:Alkenes / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D000081004:Cyclopentane Monoterpenes; D003517:Cyclopentanes / Q000737:chemistry / Q000494:pharmacology; D005227:Fatty Acids / Q000737:chemistry / Q000494:pharmacology; D005260:Female; D020062:Heteroptera / Q000187:drug effects* / Q000502:physiology; D039823:Iridoids / Q000737:chemistry / Q000494:pharmacology; D008297:Male; D011753:Pyrones / Q000737:chemistry / Q000494:pharmacology; D012543:Scent Glands / Q000737:chemistry; D012724:Sex Attractants / Q000737:chemistry / Q000494:pharmacology*; D012862:Skatole / Q000737:chemistry / Q000494:pharmacology; D012903:Smell; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D000473:Alkanes; D000475:Alkenes; D000081004:Cyclopentane Monoterpenes; D003517:Cyclopentanes; D005227:Fatty Acids; D039823:Iridoids; D011753:Pyrones; D012724:Sex Attractants; C115644:nepetalactone; C008664:nonanal; C078796:iridodiol; C028691:1-tridecene; C008776:pelargonic acid; D012862:Skatole; C017573:nonane