The use of the juvenoid pyriproxyfen accelerates sexual maturity in mass-reared Anastrepha ludens tephritid males but reduces their tolerance to chilling and to starvation

Abstract

The Sterile Insect Technique (SIT) is a system based on the release of millions of sterile insects to prevent the reproduction of specific pest populations. However, to improve the efficacy of the SIT, sterile males must reach sexual maturity before being released to increase their probability of mating with wild females. Treatments with juvenile hormone (JH) analogs, such as pyriproxyfen (PPF), accelerate sexual maturity in sterile Anastrepha ludens (Loew) (Diptera: Tephritidae) males. We hypothesized that speeding up this life-history trait can affect male resistance to stressors such as chilling and starvation. In this study, we compared some quality control parameters of flies of two different strains, selected to resist desiccation (DR) and non-selected flies (NS), treated with PPF, and subsequently exposed to starvation and pre-release chilling periods. We used males that were treated with PPF after emergence. The results showed that, from 4 to 6 days of age, DR PPF-fed males mated less than NS PPF-fed males. DR and NS males obtained a similar number of copulations at 7 days of age. After chilling, survival was higher in DR than in NS males. In addition, NS males showed a slight advantage in number of copulations when they reached 5 days of age but not at 6 and 7 days of age. Chill-coma recovery time was longer in PPF-fed flies than in control flies. Moreover, PPF-fed flies obtained less copulations after exposure to chilling at 5 days of age compared to non-chilled flies. These results indicate that sexual maturity is accelerated in PPF-fed males, especially in NS flies. However, using PPF as a pre-release treatment for A. ludens results in a reduction in male quality, regardless of whether they are DR or NS.