Olfactory and physical manipulation by males on life‐history traits in Echinothrips americanus MORGAN 1913 (Thysanoptera: Thripidae)

Abstract

Thrips are highly successful invaders due to their broad host range, cryptic lifestyle, fast development of insecticide resistance and adaptability to changing environmental conditions. Echinothrips americanus is native to the eastern USA and has now spread to over 30 countries, including Europe, Asia and Australia. This species is able to adapt oviposition rate, duration of larval development and sex ratio of progeny in relation to the mating status of the mother and presence of males. We designed experiments to distinguish between the mechanical and olfactory male contact for these changes in longevity, fecundity and developmental time of E. americanus. Individuals were reared either pairwise or with known male pheromonal substances (dimethylglutarate DBE‐5 and dimethyladipate DBE‐6), but separated by gauze from each other, which allows olfactory perception but no physical contact. Longevity, fecundity of the parents as well as developmental time and sex ratio of the progeny were recorded. Mated females had a significantly lower longevity under the impact of DBE‐5, compared to virgin ones. On the other hand, mating status itself is shown to affect oviposition rate and total fecundity, as well as developmental time of the progeny. Offspring of mated females had a slower development, compared to offspring of virgin mothers. Alternative strategies for integrative pest management that use male‐produced pheromones are discussed.