Effect of kairomones from egg and female adult stages ofOstrinia nubilalis (H�bner) (Lepidoptera, Pyralidae) onTrichogramma brassicae Bezdenko (Hymenoptera, Trichogrammatidae) female kinesis

Abstract

Volatile chemicals emanating from the different developmental stages ofOstrinia nubilalis Hübner (Lepidoptera, Pyralidae) increase the mobility ofTrichogramma brassicae Bezdenko (Hymenoptera, Trichogrammatidae) in a linear airflow olfactometer. In this paper, we have demonstrated that airborne chemicals from egg masses and virgin females during calling activity stimulate an intensive search behavior byTrichogramma females. On the other hand, emanations from mated females with extruded abdominal tips do not incite the parasitoid's movement. For the moment we cannot elucidate, with these bioassays, the real role of these kairomones as attractants, guides, stimulants, or retainers.

Host Searching by Egg Parasitoids: Exploitation of Host Chemical Cues

“…Among the Trichogrammatidae, T. brassicae (Renou et al 1989, 1992, Frenoy et al 1992 and T. ostriniae Pang and Chen (Bai et al 2004, Yong et al 2007 were the most investigated. Females of T. brassicae responded in a linear olfactometer to Ostrinia nubilalis Hübner eggs, and to chemical extracts from eggs of O. nubilalis and M. brassicae.…”

Kairomonal effect of sex pheromone components of two lepidopteran olive pests on Trichogramma wasps

“…Trichogramma parasitoids utilise sex pheromones from calling moths to locate their host (Noldus et al, 1985;Noldus, 1988;Frenoy et al, 1992;Colazza et al, 1997;Fiaboe et al, 2003). In addition, the egg itself can be a direct source of kairomones (Frenoy et al, 1992;Boo & Yang, 2000) and recently oviposition-inducing plant cues have been reported to arrest Trichogramma parasitoids (Fatouros et al, 2005).…”

“…In addition, the egg itself can be a direct source of kairomones (Frenoy et al, 1992;Boo & Yang, 2000) and recently oviposition-inducing plant cues have been reported to arrest Trichogramma parasitoids (Fatouros et al, 2005). In a field experiment, Lewis et al (1982) reported an increase of parasitism rate on Heliothis zea eggs by Trichogramma spp., on cotton plots treated with a synthetic pheromone blend of H. zea.…”

“…Many of them use semiochemicals emitted from their hosts, or their hosts' habitats, as cues to host location (Noldus, 1988;Noldus et al, 1991a;Godfray, 1994). Host semiochemicals, such as sex pheromones, chemicals produced by larval feeding activity, chemicals from larval frass or plant volatiles used by herbivore insects to locate their hosts, may serve as kairomonal or synomonal cues for parasitoids (Noldus, 1989;Hilker & Meiners, 1999;Abdelgader & Mazomenos, 2002;Romeis et al, 2005;Fatouros et al, 2008).Trichogramma parasitoids utilise sex pheromones from calling moths to locate their host (Noldus et al, 1985;Noldus, 1988;Frenoy et al, 1992;Colazza et al, 1997;Fiaboe et al, 2003). In addition, the egg itself can be a direct source of kairomones (Frenoy et al, 1992;Boo & Yang, 2000) and recently oviposition-inducing plant cues have been reported to arrest Trichogramma parasitoids (Fatouros et al, 2005).…”

“…Chemical espionage of host sex pheromones by egg parasitoids as indirect evidence of the local presence of host eggs is well documented by an increasingly available body of literature (Noldus, 1989;Godfray, 1994;Stowe et al, 1995;Smith, 1996;Powell, 1999;Fatouros et al, 2008). It is also documented that when an insect host employs a multicomponent pheromone system not all the components are required to elicit responses in parasitoids or the wasps respond only to the complete blend of calling moths (Noldus & van Lenteren, 1985;Kaiser et al, 1989;Frenoy et al, 1992). T. evanescens does not respond to (Z)-11-hexadecenyl acetate, the main component of the sex pheromone of Mamestra brassicae (Noldus & van Lenteren, 1985;Van de Veire & Dirinck, 1986).…”