Precocious sexual signalling and mating in Anastrepha fraterculus (Diptera: Tephritidae) sterile males achieved through juvenile hormone treatment and protein supplements

Abstract

Sexual maturation of Anastrepha fraterculus is a long process. Methoprene (a mimic of juvenile hormone) considerably reduces the time for sexual maturation in males. However, in other Anastrepha species, this effect depends on protein intake at the adult stage. Here, we evaluated the mating competitiveness of sterile laboratory males and females that were treated with methoprene (either the pupal or adult stage) and were kept under different regimes of adult food, which varied in the protein source and the sugar:protein ratio. Experiments were carried out under semi-natural conditions, where laboratory flies competed over copulations with sexually mature wild flies. Sterile, methoprene-treated males that reached sexual maturity earlier (six days old), displayed the same lekking behaviour, attractiveness to females and mating competitiveness as mature wild males. This effect depended on protein intake. Diets containing sugar and hydrolyzed yeast allowed sterile males to compete with wild males (even at a low concentration of protein), while brewer´s yeast failed to do so even at a higher concentration. Sugar only fed males were unable to achieve significant numbers of copulations. Methoprene did not increase the readiness to mate of six-day-old sterile females. Long pre-copulatory periods create an additional cost to the management of fruit fly pests through the sterile insect technique (SIT). Our findings suggest that methoprene treatment will increase SIT effectiveness against A. fraterculus when coupled with a diet fortified with protein. Additionally, methoprene acts as a physiological sexing method, allowing the release of mature males and immature females and hence increasing SIT efficiency.

Sexual inhibition of female Queensland fruit flies mated by males treated with raspberry ketone supplements as immature adults

“…While Gomez‐Simuta, Diaz‐Fleischer, Arredondo, Díaz‐Santiz, and Pérez‐Staples () found that female Mexican fruit flies mated by young methoprene‐treated males exhibited normal levels of sexual inhibition, Abraham et al. () found that females of South American fruit fly that mated with 6‐day‐old methoprene‐treated males, the age at which elevated mating propensity and competitiveness is expressed (Liendo et al., ; Segura et al., , ) remated more often and sooner than females mated with mature males that had not received methoprene treatment. These results suggest a decoupling of sexual maturation in terms of mating behaviour and reproductive development in terms of underlying morphology and physiology.…”

Evaluating mating compatibility within fruit fly cryptic species complexes and the potential role of sex pheromones in pre-mating isolation

“…This protocol has the advantage that it can provide information on both relatively long and close distance recognition. Several examples of the use of walk-in field cages to assess tephritid attraction to different odor sources can be found in the literature (Webb et al 1983, Shelly 2000a, 2000b, López-Guillén et al 2011, Liendo et al 2013, Milet-Pinheiro et al 2014). However, the usefulness of walk-in field cages to assess preference of female flies for pheromones of con-specific vs hetero-specific males has not been evaluated yet.…”

“…To determine whether Anastrepha fraterculus male pheromones from two different populations were equally attractive to con-specific and hetero-specific females, the methodology of Liendo et al (2013) was adapted, which in turn is an adaptation of the methodology proposed by Shelly (2000a) for Ceratitis capitata (Box 2). The experiments were carried out in a greenhouse of the (IPCL)FAO/IAEA Insect Pest Control Laboratory in Seibersdorf, Austria and involved one population from Piracicaba, São Paulo, Brazil and one from Tucumán, Argentina.…”

Mate choice confers direct benefits to females ofAnastrepha fraterculus(Diptera: Tephritidae)

“…This argues against the idea that the lack of benefits associated to methoprene lays on the fact that methoprene is a synthetic compound. Methoprene is similar to JH in chemical structure and, more importantly, its role on A. fraterculus seems to replicate that of JH [55,71,72]. Therefore, the strong preference of females for methoprene-treated males could, still, be associated to other benefits, yet unidentified.…”