Influence of hormones and protein on the males' competitiveness of the Caribbean fruit fly

Juvenile hormones levels and the adult diet probably have an important effect on the attractiveness and competitiveness of the male Caribbean fruit fly. Since the success of the Sterile Insect Technique (SIT) requires the release of males that can compete in the wild, these effects are of crucial importance. A study was conducted to compare male Anastrepha suspensa sexual performance when submitted to four different treatments: (A) Application of Juvenile Hormones (JH) and sugar and hydrolyzed protein as adult food (JH+P+); (B) Application of JH and sugar as adult food (JH+P-); (C) No application of JH and sugar and hydrolyzed protein as adult food (JH-/P+); and (D) No application of JH and sugar as adult food (JH-/P-). Methoprene, a synthetic juvenile hormone analog, was applied topically in the first 24 hours after adult emergence at a rate of 5μg in an acetone solution per fly. The adult diet was composed of sugar and water ad libitum in P- treatments. In P+ treatments protein was added to the adult diet (mixed with sugar in a proportion of 3 parts of sugar and 1 part of protein). The flies used were from a 'semi-wild' colony, i.e. less than 1 year in domestication. Mating success among sexual mature males from the 4 treatments, in small cages in laboratory and in field cages was observed. Of 180 female in laboratory cages (1 female and 1 male from each treatment per cage) 131 mated. From that: 55% mating were with (JH+P+) males; 22% with (JH+P-); 18% with (JH-/P+); and 5% with (JH-/P-). Field cage tests are planned for early October 2004 with 60 males (15 per treatment) and 30 females per cage. The results show that 59% mating were with (JH+P+) males; 18% with (JH+P-); 20% with (JH-/P+); and 3% with (JH-/P-). The data obtained from the laboratory and field cage tests, show a clear improvement of male competitiveness due to the hormone application, protein supply, and interaction of hormone and protein