CHEMICAL ECOLOGY Sex Attraction in Bactericera cockerelli (Hemiptera: Triozidae)

The potato psyllid,Bactericera ( Paratrioza) cockerelli (Šulc) (Hemiptera: Triozidae), is a major pest of potato. We examined the role of chemical signals in sex attraction, assessing male and female response to maleand female-produced volatile chemicals. In laboratory olfactometer assays, potato psyllid males were attracted to odorants emitted from live females and from solvent extractof females.These results indicate that the female-producedchemicals responsible for attracting males may be isolated by means of insect extractions. Males were also attracted to volatile chemicals frommales and extracts ofmales, providing the Þrst example ofmaleÐmale attraction in the Psylloidea. Males exposed simultaneously to odorants from conspeciÞc females and males were preferentially attracted to female odorants, suggesting the presence of a female-speciÞc sex attractant for males. Potato psyllid females avoided volatile chemicals emitted by females and extracts of females and by volatile chemicals emitted by males and extracts of males. Possible explanations for avoidance of conspeciÞcs by females are discussed. This study is the Þrst report of male attraction to volatile chemicals emitted by females and female extracts in the Triozidae andmore speciÞcally in the potato psyllid.