Potential for pre‐release diet supplements to increase the sexual performance and longevity of male Queensland fruit flies

Abstract

1 Recent studies have shown that continuous access to a protein source (yeast hydrolysate) can greatly enhance the sexual performance of male Queensland fruit flies ( Bactrocera tryoni ; 'Q-flies'). However, in Sterile Insect Technique programmes used to eradicate or suppress wild populations, mass-reared Q-flies are typically fed only sucrose and water for up to 2 days before release. 2 We investigated whether adding a protein source to the diet of male Q-flies for a 24-or 48-h window after emergence and then removing it is sufficient to enhance mating probability, latency to mate, copula duration, probability of sperm storage, number of sperm stored, female remating tendency and longevity of male Q-flies. 3 Protein-fed males were more likely to mate than males fed only sucrose, especially when young. Protein-fed males also had shorter mating latencies and longer copulations than protein-deprived males. 4 Females mated by protein-fed males were more likely to store sperm, stored more sperm and were less likely to remate than were females mated by proteindeprived males. Females were also less likely to remate if their first mate had been large. 5 Overall, providing male Q-flies access to a protein source for a 24-or 48-h window early on in their adult life was sufficient to greatly enhance all assessed measures of performance. Although 24-h access was sufficient for a notable enhancement, further benefits were evident in males provided 48-h access. 6 The results are discussed in terms of the practical implications for Sterile Insect Technique programs used to eradicate or suppress wild Q-fly populations.

Condition-dependent ejaculate size and composition in a ladybird beetle

“…Low-condition males transferred more sperm despite their reduced copulation duration by transferring sperm at a faster rate than high-condition males, and this occurred despite the trend that high-condition males transferred retained (nonsperm) ejaculate at a faster rate (table 1). In contrast to our result, previous experimental studies in flies and flour beetles have found that improved male condition leads to increased absolute sperm transfer (Fedina & Lewis 2006;McGraw et al 2007;Perez-Staples et al 2008); however, these studies did not report sperm concentration and as a result it is not possible to determine whether and how ejaculate composition differed. An alternative explanation for our result is that females mating with low-or high-condition males differed in sperm storage or usage in the hour following mating.…”

“…Empirical studies involving experimental manipulations of condition generally support this prediction, reporting that highcondition males produce larger ejaculates (Gwynne 1990;Delisle & Bouchard 1995;Watanabe & Hirota 1999;Jia et al 2000;Ferkau & Fisher 2006;Lewis & Wedell 2007;Blanco et al 2009; but see Wedell 1993), transfer more sperm (Fedina & Lewis 2006;McGraw et al 2007;Perez-Staples et al 2008), and produce more ejaculate-derived nuptial gifts (Jia et al 2000; but see Wedell 1993).…”

Female Age Determines Remating Behavior in Wild Mexican Fruit Flies

“…However, in another study on this same species, female remating was not influenced by male age (from 4 to 20 days-old) (Costa et al 2012). Likewise, in the Queensland fruit fly Bactrocera tryoni, male age did not affect their ability to inhibit female remating (Pérez-Staples et al 2008). Finally, in the butterfly Bicyclus anynana, females mated with old males had higher remating propensity and shorter refractory periods than females mated with young males (Karl and Fischer 2013).…”

“…Specially, it can affect copulation duration (Koref-Santibanez 2001;Pérez-Staples et al 2008, mating success (Zuk 1988;Jones 2000;Jones and Elgar 2004;Fricke and Maklakov 2007;Pérez-Staples et al 2010;Papanastasiou et al 2011) and sperm traits (Taylor et al 2001;Pérez-Staples et al 2008;Papanastasiou et al 2011;Costa et al 2012;Decanini et al 2013;Santhosh and Krishna 2013). Females may prefer to mate with young males as they have less deleterious mutations in the germline and are more fertile Price 1995, 1999;Beck and Powell 2000;Beck and Promislow 2007).…”

Protein and carbohydrate intake influence sperm number and fertility in male cockroaches, but not sperm viability

“…Moreover, the small number of studies that have examined this relationship in insects have yielded equivocal results. Queensland fruitflies (Bactrocera tryoni) [27], Drosophila melanogaster [28], red flour beetles (Tribolium castaneum) [29] and Indian meal moth (Plodia interpunctella) [30] all show an increase in sperm production on higherquality diets, whereas studies on ladybirds (Adalia bipunctata) [31] and Mediterranean fruitflies (Ceratitis capitata) [32] show the reverse pattern. Only two of these studies have examined the consequences of diet-induced changes in sperm production for male fitness: the increase in sperm production observed on a high-quality diet results in a higher paternity in T. castaneum [29] but not in D. melanogaster [28].…”