Isolation of a Female-Emitted Sex Pheromone Component of the Fungus Gnat, Lycoriella ingenua, Attractive to Males

Abstract

Lycoriella ingenua Dufour (Diptera: Sciaridae) is acknowledged as the major pest species of the white button mushroom, Agaricus bisporus, throughout the world. Components of the female-produced sex pheromone of this species were identified previously as C15-C18 n-alkanes, with the major component n-heptadecane, and shown to be attractive to L. mali. However, a subsequent report could not repeat this work. We reinvestigated the sex pheromone of this species by confirming that virgin females were attractive to males in a Y-tube bioassay and by collection of extracts from virgin females. Extracts were analyzed by gas chromatography coupled to electroantennographic detection, and by the less widely-used technique of gas chromatography coupled to a behavioral bioassay to detect compounds causing wing-fanning and copulatory abdomen curling in males. A single, behaviorally-active pheromone component was isolated and characterized by gas chromatography coupled to mass spectrometry. This component was definitively not n-heptadecane or any of the other C15-C19 n-alkanes reported previously, but is proposed to be a sesquiterpene alcohol having analytical characteristics that closely matched those of reference germacradienols.

Efficacy of Beauveria bassiana formulations against the fungus gnat Lycoriella ingenua

“…Adult flies emerged approximately 21 days later, at which point fresh compost cups were provided for egg collection from the emerging adults. New cages were then utilized until a continuously emerging colony was established as described in Andreadis et al (2015).…”

Little effect of delayed mating on fecundity or fertility of female fungus gnats Lycoriella ingenua

“…Despite the lack of mating disruption experimentation thus far with L. ingenua , we consider that a pre‐emptive examination of the potential effects of mating disruption in delaying mating in L. ingenua is warranted. We also consider it important to assess, ahead of time, whether delaying mating might increase the chances that successful mating disruption can occur and suppress populations of this pest, whenever the germacradienol pheromone component (Andreadis et al ., ) is finally completely characterized and synthesized. Our data suggest that, if the synthetic L. ingenua germacradienol sex pheromone component is able to be deployed for mating disruption in the future, it would not significantly reduce female fecundity or fertility if matings by females were delayed for 5 days or less by the pheromone.…”

“…Adult female L. ingenua flies produce a form of germacradienol, a sesquiterpene alcohol, which serves as a sex pheromone component to attract male conspecifics in laboratory Y-tube bioassays (Andreadis et al, 2015). In gas chromatography-behaviour coupled bioassays, the germacradienol elicits male wing-fanning and abdomen curling (Andreadis et al, 2015). The stereochemistry of this L. ingenua sex pheromone component remains to be fully characterized, although work is continuing to definitively identify its structure.…”

Fungal Volatiles as Olfactory Cues for Female Fungus Gnat, Lycoriella ingenua in the Avoidance of Mycelia Colonized Compost

“…Intraspecific communication of Sciaridae has been studied since the 1980s and there is evidence for the role of sex pheromone in mate-finding behavior (Alberts, et al 1981 ; Frank and Detter 2008 ; Li et al 2007 ). Gas chromatography electroantennographic detection (GC-EAD) and gas chromatography/behavioral bioassay (GC-BB) analyses have recently been used for Lycoriella ingenua for isolation of sex pheromones (Andreadis et al 2015 ). However, studies focusing on the role of physiologically active volatiles in host-finding or in characterization of repellent chemicals upon these insects remain limited.…”