Abstract
BackgroundThe New World Screwworm fly (NWS), Cochliomyia hominivorax, is an ectoparasite of warm-blooded animals and a major pest of livestock in parts of South America and the Caribbean where it remains endemic. In North and Central America it was eradicated using the Sterile Insect Technique (SIT). A control program is managed cooperatively between the governments of the United States and Panama to prevent the northward spread of NWS from infested countries in South America. This is accomplished by maintaining a permanent barrier through the release of millions of sterile male and female flies in the border between Panama and Colombia. Our research team demonstrated the utility of biotechnology-enhanced approaches for SIT by developing a male-only strain of the NWS. The strain carried a single component tetracycline repressible female lethal system where females died at late larval/pupal stages. The control program can be further improved by removing females during embryonic development as larval diet costs are significant.ResultsThe strains developed carry a two-component system consisting of the Lucilia sericata bottleneck gene promoter driving expression of the tTA gene and a tTA-regulated Lshid proapoptotic effector gene. Insertion of the sex-specifically spliced intron from the C. hominivorax transformer gene within the Lshid gene ensures that only females die when insects are reared in the absence of tetracycline. In several double homozygous two-component strains and in one “All-in-one” strain that had both components in a single construct, female lethality occurred at the embryonic and/or first instar larval stages when raised on diet without tetracycline. Laboratory evaluation for phenotypes that are relevant for mass rearing in a production facility revealed that most strains had fitness characteristics similar to the wild type J06 strain that is currently reared for release in the permanent barrier. Testing of an “All in one” strain under mass rearing conditions showed that the strain maintained the fitness characteristics observed in small-scale rearing.ConclusionsThe early female lethal strains described here could be selected by the NWS Control Program for testing at large scale in the production facility to enhance the efficiency of the NWS eradication program.
Highlights
The New World Screwworm fly (NWS), Cochliomyia hominivorax, is an ectoparasite of warm-blooded animals and a major pest of livestock in parts of South America and the Caribbean where it remains endemic
Females produce no viable offspring, gradually reducing insect populations over time. This non-chemical pest control method was originally developed to reduce populations of the New World screwworm (NWS), Cochliomyia hominivorax (Diptera, Calliphoridae), in the United States, where it succeeded in eradicating this ectoparasite of warm-blooded animals from the whole country and later from Mexico and Central America [4, 6, 7]
An early lethal transgenic sexing system for C. hominivorax A series of Driver and Effector constructs were previously designed for their application to a range of blow flies, including the Australian sheep blow fly Lucilia cuprina, the European green blow fly L. sericata, the Old World primary screwworm Chrysomya bezziana, the secondary screwworm C. macellaria, and the NWS [20, 23]
Summary
The New World Screwworm fly (NWS), Cochliomyia hominivorax, is an ectoparasite of warm-blooded animals and a major pest of livestock in parts of South America and the Caribbean where it remains endemic. Females produce no viable offspring, gradually reducing insect populations over time This non-chemical pest control method was originally developed to reduce populations of the New World screwworm (NWS), Cochliomyia hominivorax (Diptera, Calliphoridae), in the United States, where it succeeded in eradicating this ectoparasite of warm-blooded animals from the whole country and later from Mexico and Central America [4, 6, 7]. After this landmark success, SIT was adapted to manage effectively the populations of other economically important agricultural insect pests such as the Medfly and the Mexican fruit fly [8]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
