A Male-Predominant Cuticular Hydrocarbon, 7-Methyltricosane, is used as a Contact Pheromone in the Western Flower Thrips Frankliniella occidentalis

Abstract

In a laboratory bioassay, adult female Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) spent more time near filter paper disks that had been exposed to adult males than near unexposed disks; this effect was not observed on disks exposed to adult females. The response could only partly be explained by the known male-produced aggregation pheromone, neryl (S)-2-methylbutanoate, suggesting the presence of an unknown male-produced compound. In gas chromatography/mass spectrometry analyses, 7-methyltricosane was detected on disks exposed to males, but not on disks exposed to females. Extracts of cuticular lipids also showed relatively large amounts of 7-methyltricosane on males, whereas only trace amounts were found on females and none on larvae. Bioassays of synthetic 7-methyltricosane showed that adults responded only after contact. The response to this compound was clearly different from that to n-tricosane or hexane-only controls. Females that contacted 7-methyltricosane on glass beads stayed in the vicinity and frequently raised the abdomen, a behavior that rejects mating attempts by males. Males stayed in the vicinity and wagged the abdomen sideways, a behavior used in fighting between males. This is the first identification of a contact pheromone in the order Thysanoptera.

Isolation and determination of absolute configurations of insect-produced methyl-branched hydrocarbons

“…Thus, many studies have been correlational only, showing statistically significant differences in the amounts and/or types of compounds present, without being able to confirm that any one or any group of these compounds do indeed have a signaling role. Other studies have bioassayed synthesized CHCs to probe the roles of specific compounds, with some success (15)(16)(17)(18)(19)(20)(21)(22). However, this approach is limited by the large number of compounds in CHC extracts so that a single study might require syntheses of numerous standards to assess the functional roles of all possible components.…”

“…Methyl-branched cuticular hydrocarbons (MBCHs) have been identified or implicated as contact pheromones in a number of insect species (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27), but most studies involving MBCHs have ignored the issue of stereochemistry and used only racemic MBCHs in bioassays to assess function. The linked questions as to whether insects biosynthesize MBCHs enantioselectively and whether insects can discriminate between the stereoisomeric Significance Methyl-branched hydrocarbons (MBCHs) are widely used for inter-and intraspecific communication by insects.…”

The aggregation pheromones of thrips (Thysanoptera) and their potential for pest management

“…occidentalis, but since it appears to act only by contact, its potential for pest management appears to be limited (Olaniran et al, 2013). Anti-aphrodisiac pheromones have been discovered in Echinothrips americanus Morgan (Krueger et al, 2016) and such pheromones could be useful for mating disruption (see below).…”

A protocol and calibration method for accurate multi-camera field videography

“…Hayashi et al, 2009;Olaniran et al, 2013;Bhandiwad et al, 2013). For example, in 2012, 70 papers published in The Journal of Experimental Biology reported using video to measure kinematics, representing 11% of the papers published in the journal that year.…”