Original paper
Cuticular hydrocarbon composition does not allow Harmonia axyridis males to identify the mating status of sexual partners
Legrand, Pauline; Vanderplanck, Maryse; Lorge, Stéphanie; Maesen, Philippe; Lognay, Georges; Vilcinskas, Andreas; Vogel, Heiko; Estoup, Arnaud; Foucaud, Julien; Francis, Frédéric; Facon, Benoit; Verheggen, François J.
Entomologia Generalis Volume 38 Number 3 (2019), p. 211 - 224
published: Mar 22, 2019
manuscript accepted: Oct 2, 2018
manuscript revision received: Oct 1, 2018
manuscript revision requested: Nov 1, 2017
manuscript received: Sep 21, 2017
DOI: 10.1127/entomologia/2019/0552
ArtNo. ESP146003803001, Price: 15.40 €
Abstract
Males of polyandrous species have to overcome sperm competition. They should select their mate based on the reproductive status of the female to increase their own fitness. Because the sexual behavior of lady beetles relies on semiochemicals, with cuticular hydrocarbons (CHCs) being used for mate recognition, we developed and tested two hypotheses. First, we hypothesized that the cuticular hydrocarbon profile qualitatively and quantitatively differs between virgin and mated Harmonia axyridis females, regardless of the color morph. Second, we hypothesized that males discriminate virgin and mated females, preferring copulating with virgin females, rather than previously mated ones, to avoid sperm competition and subsequently increase their fitness. CHCs were solvent-extracted before being quantified and identified by gas chromatography. We found no qualitative differences between mated and unmated females irrespective of the morph; however, quantitative differences were detected. Specifically, the CHC profiles of mated females presented higher concentrations of alkenes, including 9-pentacosene, 9-heptacosene, and 9-hentriacontene. During dual-choice behavioral assays, males equally copulated with virgin and mated females. Our results suggest that there is no CHC-based discrimination strategy in virgin males of H. axyridis between virgin and once-mated females. We discuss alternative strategies that might be used in this lady beetle species.
Keywords
Multicolored Asian lady beetle • sexual competition • mate selection • chemical signal • CHC • mating history • multiple mating