Location: Chemistry ResearchTitle: Precocious sexual signalling and mating in Anastrepha fraterculus (Diptera: Tephritidae) sterile males achieved through juvenile hormone treatment and protein supplements Author
Submitted to: Bulletin of Entomological Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/25/2012
Publication Date: 8/17/2012
Citation: Liendo, M.C., Devescovi, F., Bachmann, G.E., Utges, M.E., Abraham, S., Vera, M.T., Lanzavecchia, S.B., Bouvet, J.P., Gomez-Cendra, P., Hendrichs, J., Teal, P.E., Cladera, J.L., Segura, D.F. 2012. Precocious sexual signalling and mating in Anastrepha fraterculus (Diptera: Tephritidae) sterile males achieved through juvenile hormone treatment and protein supplements. Bulletin of Entomological Research. 10-22. Interpretive Summary: The South American fruit fly is a quarantine pests of significant importance to crops and a potential invasive pest for the US. One way to control this pest is the sterile insect technique (SIT) in which the natural population of pests is flooded by releasing sterile males who mate with wild females. However males take two weeks to become mature and suffer considerable mortality during that time. Additionally, sterile males are less effective in attracting mates than are wild males. Scientists at the National Scientific Research and Technical Center, Argentina, University of de Buenos Aires, Argentina, National University of Tucumán, Argentina, E. A. Favret Institute of Genetics, INTA, Buenos Aires, Argentina, Agricultural Experiment Station, Concordia, Argentina, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, Insect Pest Control Section, Vienna, Austria and Center for Medical, Agricultural, and Veterinary Entomology, US Department of Agriculture – Agricultural Research Service, Florida, USA determined that adding both protein and methoprene to diet of sterile males reduced the time it takes for males to become sexually mature and improved their mating performance significantly. This result is important for application of these technologies to improving the Sterile Insect Technique because treated males have higher sexual success and reach sexual maturity several days earlier than untreated males and live just as long as untreated males.
Technical 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.