Sex pheromones in three Bradysia species (Dipt., Sciaridae): novel bioassays with female body extracts and fractions

Abstract

Females of the fungus gnat species Bradysia difformis, Bradysia optata and Bradysia tilicola are able to produce sexual attractants. In males, the female extracts elicit species‐specific courtship behaviour and attraction in an olfactometer bioassay. Attractiveness of the sex pheromone extracts seems to differ in the investigated species, being highly attractive for males in B. difformis and only moderately attractive in B. tilicola. Female B. difformis are attractive from late pupal stages until death of the imago. In contrast, female B. optata and B. tilicola are not attractive to males before emergence from the pupa and attractiveness decreases in older females. The pheromones seem to be located on the surface of several body compartments of freshly emerged females. Sexual pheromones of all three species represent multicomponent blends and can be separated in several fractions via thin layer chromatography (TLC). Males of all species show courtship behaviour when placed on developed TLC sheets, indicating the position of the biologically active compounds. In B. difformis and B. optata, the most non‐polar TLC fraction is attractive to males, whereas the single fractions of B. tilicola‐pheromone elicited almost no attraction of males.

Nieuwe methoden voor bestrijding van bodemplagen in de glastuinbouw en zomerbloemen. : Deel 2: Literatuurstudie rouwmuggen (Sciaridae) en oevervliegen (Ephydridae)

“…Uit een studie van Sonoda et al (2014) Alhoewel voor verschillende soorten rouwmuggen bekend is dat de vrouwtjes sexferomonen produceren (e.g. Alberts et al 1981, Gotoh et al 1999, Liu et al 2002, Frank and Dettner 2008, zijn deze sexferomonen nog niet chemisch gekarakteriseerd. Er zijn geen lokstoffen bekend die de oevervlieg S. tenuicosta aantrekken en ook zijn er geen studies gedaan naar (sex)feromonen in oevervliegen.…”

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 ).…”