Strategic sperm allocation in the red flour beetle
Project start: From summer 2021
Background: Not only females but also males are expected to allocate their gametes prudently. Sexual selection theory predicts that males should adjust the number of transferred sperm in response to the risk of sperm competition. In T. castaneum males transfer a spermatophore to the female, containing sperm and seminal fluid (Qazi et al. 2015). It has been shown that the spermatophore is apparently only filled with sperm by the male, after the spermatophore is already transferred to the female (Fedina 2007). This might enable males to plastically adjust the amount of transferred sperm during mating. We might test the hypothesis of plastic sperm allocation in response to sperm competition by comparing the number of transferred sperm between virgin and mated females or between females of different size. This project requires preliminary experiments to establish a protocol to quantify the amount of sperm transferred to a female. The project would involve observation of mating behaviour and sperm microscopy techniques.
Fedina TY. 2007. Cryptic female choice during spermatophore transfer in Tribolium castaneum (Coleoptera: Tenebrionidae). J Insect Physiol. 53(1):93–98.
Qazi MCB, Herbeck JT, Lewis SM. 2015. Mechanisms of Sperm Transfer and Storage in the Red Flour Beetle ( Coleoptera : Tenebrionidae ). Ann Entomol Soc Am. 89(6):892–897.