Investigation of Long-Range Female Sex Pheromone of the European Tarnished Plant Bug, Lygus rugulipennis: Chemical, Electrophysiological, and Field Studies

Abstract

The European tarnished plant bug, Lygus rugulipennis, is an important pest of agricultural and horticultural crops throughout Europe. Adult male L. rugulipennis were previously shown to be attracted to traps baited with live virgin females, which suggests the females produce a sex pheromone. Volatiles produced by virgin female L. rugulipennis were shown to contain three components, hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal which elicited electroantennographic (EAG) responses from males in analyses by linked gas chromatography-electroantennography (GC-EAG). They were produced in 1.5:1:0.08 ratio, respectively, by single females. Collections from 1, 2, or 4 virgin females showed the proportions of hexyl butyrate and (E)-4-oxo-2-hexenal to increase relative to that of (E)-2-hexenyl butyrate with increasing number of females. Although these compounds were found in body extracts of both male and female L. rugulipennis, they were not detected in volatiles released by virgin males. EAG dose-response studies showed that both males and females responded to these chemicals with minimal differences in sensitivity between the sexes or to the three components, except that males were more responsive than females to (E)-4-oxo-2-hexenal at the two highest doses tested. Release rates of the compounds from rubber septa, polyethylene vials, and polyethylene sachets were measured under laboratory conditions. Four field tests were carried out using sticky traps baited with all possible binary and tertiary combinations of the three chemicals using different combinations of dispensing systems. Catches of male L. rugulipennis in baited traps were similar to those in unbaited traps. Significantly fewer females were caught on traps baited with blends containing hexyl butyrate than on traps without hexyl butyrate or unbaited traps in one test and overall. The roles of the three compounds and possible reasons for their failure to attract males are discussed.

Attraction of Lygus rugulipennis and Adelphocoris lineolatus to synthetic floral odour compounds in field experiments in Hungary

“…For L. rugulipennis, some compounds were identified as components of the sex pheromone (Innocenzi et al 2004), and attraction of males to these compounds has been reported (Innocenzi et al 2005;Fountain et al 2010). However, in traps baited with the two floral attractants discovered in our present study, both sexes of L. rugulipennis were caught, thus these compounds may show practical advantages over the use of sex pheromones.…”

Sex attractant pheromone of the sorghum plant bug Stenotus rubrovittatus (Matsumura) (Heteroptera: Miridae)

“…The blend of all three components attracted fewer males than the binary blend (Innocenzi et al, 2005); however, no combination of the three component chemicals was observed to attract males of other species. Innocenzi et al (2004) observed that the release rate of (E)-4-oxohex-2-enal drastically decreased when this compound was in the presence of hexyl butyrate. They considered that this phenomena was caused by the chemical interaction between hexyl butyrate and (E)-4-oxohex-2-enal, so they designated that the butyrates and (E)-4-oxohex-2-enal should be applied separately (Innocenzi et al, 2005).…”

“…Although the reason for this inconsistency was not clear, it may have been the influence of the chemical stabilizer and/or sunshade. In the present study, BHT and S-300 were used as chemical stabilizers and an aluminum-foil cup was used as a sunshade, while these were not used by Innocenzi et al (2004Innocenzi et al ( , 2005.…”

“…To evaluate the effects of chemical interaction between butyrates and (E)-4-oxohex-2-enal (Innocenzi et al, 2004(Innocenzi et al, , 2005 on trap catches, male attractant activity of a septum baited with all three compounds was compared with that of two separate septa, as mentioned above. Rubber septa of each trap were treated with two septa [100 mg of hexyl butyrateϩ40 mg of (E)-hex-2-en-1-yl butyrate in septum A, and 200 mg of (E)-4-oxohex-2-enal in septum B] or one septum [100 mg of hexyl butyrateϩ40 mg of (E)-hex-2-en-1-yl butyrateϩ200 mg of (E)-4-oxohex-2-enal in septum A].…”

Design and deployment of semiochemical traps for capturing Anthonomus rubi Herbst (Coleoptera: Curculionidae) and Lygus rugulipennis Poppius (Hetereoptera: Miridae) in soft fruit crops

“…Three compounds have been identified as components of the ETB female sex pheromone (Innocenzi et al, 2004;Frati et al, 2009) and a blend of these was further optimised and tested in field trials (Innocenzi et al, 2004(Innocenzi et al, , 2005Fountain et al, 2008Fountain et al, , 2011Cross et al, 2011) to develop an effective lure and trap for monitoring males . In addition, some plant volatiles such as phenylacetaldehyde have been identified as attractants for female ETB (Frati et al, 2009;Fountain et al, 2010;Koczor et al, 2012).…”