Methoprene treatment reduces the pre‐copulatory period in Anastrepha fraterculus (Diptera: Tephritidae) sterile males

Abstract

Anastrepha fraterculus is a major fruit pest in South America. Ongoing studies support the implementation of the sterile insect technique (SIT) against this pest. Sexual readiness of sterile males is a key point for SIT application. The pre‐copulatory period of A. fraterculus males has not been reported before, but it is expected to last several days. An acceleration of sexual maturation was achieved in other Anastrepha species after topical applications of juvenile hormone analogues, like methoprene. Here, we studied the effect of methoprene on male sexual maturation, mating duration and sperm transfer in A. fraterculus as well as the impact of acetone (methoprene solvent) on survival. We also explored a method to deliver methoprene massively. Pheromone‐calling and mating ability were evaluated daily from adult emergence, and used as indicators of sexual maturity. Anastrepha fraterculus males showed a long pre‐copulatory period (7 days approximately), as other Anastrepha species. This process was accelerated after methoprene treatment (2.5 μg/μl), both in non‐irradiated and irradiated males which matured 2–3 days earlier. Mating duration for methoprene‐treated males was longer than for mature untreated males, however, no differences in sperm transfer were detected. Survival was not affected by acetone. Dipping pupae in methoprene allowed emerging males to mature as fast as those receiving topical application as adults. Dipping of pupae is a promising method to deliver massively methoprene and should be further investigated.

Improving sterile male performance in support of programmes integrating the sterile insect technique against fruit flies

“…The same was found in A. ludens and A. obliqua when the sugar/yeast ratio was 9:1 or 24:1, but not with the 3:1 ratio ) Inhibition of remating Feeding on a nitrogen-rich food significantly improved the ability of sterile males to inhibit female remating in A. fraterculus, B. tryoni and C. capitata (Harmer et al 2006;Radhakrishnan and Taylor 2007;Gavriel et al 2009;Segura et al 2013 The contribution of microorganisms to fitness of non-sterile Bactrocera oleae and C. capitata was established Ben-Yosef et al 2008aYuval et al 2013) Manipulating the microflora of sterile males suggests that probiotic supplements could improve male sexual performance in C. capitata (Niyazi et al 2004;Behar et al 2005Behar et al , 2008aBen-Ami et al 2010) these phenomena, to extend them to other species, and to transfer and validate them under large-scale conditions of action SIT programmes. Results obtained during the CRP have confirmed the compounds that have the potential to improve sterile male performance in the field and have identified some additional ones.…”

“…The ratio of protein to carbohydrates in dry diets provisioned early in adult life contributed to male sexual performance and affected survival in a dose-dependent manner in A. fraterculus, A. ludens, A. obliqua and B. tryoni (Prabhu et al 2008;Gó mez et al 2013;Liedo et al 2013;Segura et al 2013; (Yuval et al 2007;Gavriel et al 2010;Taylor et al 2013) In the laboratory, protein-fed males lived significantly longer than sugar-fed males of B. cucurbitae and B. tryoni (Haq et al 2010b;Taylor et al 2013). The same was found in A. ludens and A. obliqua when the sugar/yeast ratio was 9:1 or 24:1, but not with the 3:1 ratio ) Inhibition of remating Feeding on a nitrogen-rich food significantly improved the ability of sterile males to inhibit female remating in A. fraterculus, B. tryoni and C. capitata (Harmer et al 2006;Radhakrishnan and Taylor 2007;Gavriel et al 2009;Segura et al 2013 The contribution of microorganisms to fitness of non-sterile Bactrocera oleae and C. capitata was established Ben-Yosef et al 2008aYuval et al 2013) Manipulating the microflora of sterile males suggests that probiotic supplements could improve male sexual performance in C. capitata (Niyazi et al 2004;Behar et al 2005Behar et al , 2008aBen-Ami et al 2010) these phenomena, to extend them to other species, and to transfer and validate them under large-scale conditions of action SIT programmes.…”

“…Agar-based diet containing 5-10% protein along with 0.05% methoprene tested with A. ludens and A. suspensa produced large amounts of waste and is not cost effective Pereira et al 2013) Pupal dipping in an acetone bath containing 0.05% methoprene tested with A. fraterculus, A. ludens and A. suspensa does not impact emergence or survival and accelerates reproductive development, although causes humidity problems when handling large volumes of pupae Pupal dipping found impractical because of health risks, safety and disposal issues associated with the use of acetone Segura et al 2013) A dry sugar-protein pre-release diet containing 0.0015% methoprene for A. ludens and A. obliqua shown to be practical and effective in accelerating development when applied in operations of fly emergence and release facilities (Gó mez et al…”

Odorant-binding proteins expression patterns in recently diverged species of Anastrepha fruit flies

“…Here, we studied differential expression of OBP genes in two closely related species of the fraterculus group, Anastrepha fraterculus and Anastrepha obliqua . These species show important ecological and reproductive differences 20–24 that could be related with olfactory perception. Though A .…”

Effects of Methoprene on Female Reproduction, Longevity and F1 Progeny Development in the Cotton Bollworm MothHelicoverpa armigera(Hübner) (Lepidoptera: Noctuidae)

“…JHa may not be involved in the final stages of reproductive system development once the adults have emerged, which may explain these conflicting results (Wijayaratne et al 2012). We speculate that JHa presents pleiotropic effects on insect fecundity, perhaps because JHa is much more insect-specific and yields a dose-dependent response (Segura et al 2013). Our results are consistent with the speculation that exogenous methoprene stimulates H.armigera reproduction in a dose-dependent manner and that it stimulates fecundity and ovariole development at specific doses (Table 2; Fig.…”