CHEMICAL BIOLOGY OF INSECT AND PLANT SIGNALING SYSTEMS
Location: Chemistry Research Unit
Title: Enhancing efficacy of Mexican fruit fly SIT programmes by large-scale incorporation of methoprene into pre-release diet
Submitted to: Journal of Applied Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 11, 2011
Publication Date: August 8, 2012
Citation: Gomez, Y., Teal, P.E., Pereira, R. 2012. Enhancing efficacy of Mexican fruit fly SIT programmes by large-scale incorporation of methoprene into pre-release diet. Journal of Applied Entomology. DOI: 10.1111/j.1439-0418.2011.01695.x.
Interpretive Summary: Tephritid fruit flies are quarantine pests of significant importance to crops throughout the world. 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. Wild females that mate with sterile males do not produce viable eggs which results in eradication over time. One of the more significant costs associated with SIT protocols for Tephritid flies is the need to hold mass reared adult flies for as many as 7, or more, days prior to release because males require time to become sexually mature. Scientists at the Center for Medical Agricultural and Veterinary Entomology, USDA-ARS, Gainesville Florida, in collaboration with scientists at Insect Pest Control Section, Joint FAO/IAEA Division of Nuclear, Techniques in Food and Agriculture Vienna, Austria, the and the Programa Moscamed, Tapachula, Mexico have been studying how diet and hormone therapy can improve SIT. They have shown that addition of the hormone mimic, methoprene, accelerates reproductive development by as much as 5 days and significantly improves mating potential of sterile Mexican fruit fly males. Additionally, they have developed a simple cost effective method to provide the supplements to the large numbers of males required for field release protocols. The methods to incorporate these technologies into mass rearing of sterile flies and the technique is now in use for control of the Mexican Fruit fly in Mexico.
The juvenile hormone analog, methoprene, has been documented to accelerate development of reproductive competence and sexual signaling of Caribbean (Anstrepha suspensa), the Mexican (Anastrepha ludens), the South American (Anastrepha fraterculus) and West Indian (Anastrepha obliqua) tephritid fruit flies. The incorporation of methoprene into sterile fly release protocols at fly emergence and handling facilities is a key step required for large scale application of the technology to field release strategies. The goal of our study was to develop a method to supply, in large scale, methoprene to sterile Mexican fruit flies for release in the current Sterile Insect Technique (SIT) programme in Mexico. In field cage tests, the isolation index of sterile males after treatment with methoprene was reduced, increasing the percentage of mating between laboratory sterile males and wild females. In laboratory trials, males fed a diet containing 0.05% or 0.1% methoprene mated 4-days earlier than untreated control males. In a pilot area tested in 3 500 ha to measure the impact of the sterile releases when methoprene was supplied, no adult wild flies were detected and no larvae were found after sampling more than 330 kg of fruit. Based on the results obtained in this study we recommend the incorporation of the methoprene on adult diet to improve the Mexican fruit fly male sexual performance when release in the field, contributing for the increase of the cost-effectiveness of the SIT programme.