Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 18, 2004
Publication Date: June 30, 2004
Citation: Allen, M.L., Berkebile, D.R., Skoda, S.R. 2004. Post-larval fitness of transgenic strains of Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae). Journal of Economic Entomology. 97(3):1181-1185. Interpretive Summary: Transgenic insects have foreign DNA inserted permanently (ie. inherited by offspring) into the genome. Pest insects can be mass reared, sterilized, and released to suppress their populations; a technique known as sterile insect technique (SIT). If transgenic insects are to be used in SIT, it is crucial that they can be successfully mass reared and able to mate with wild insects once released. The work presented here compares eight strains of transgenic insects to a strain currently used in an SIT program, the New World Screwworm Eradication Program. Characteristics compared were pupal mass, adult emergence, and male ratio for all strains. Additionally, one transgenic strain was compared to the SIT strain for ability of males to compete for mates. In all tests, the transgenic strains showed similar characteristics to the SIT strain, indicating that the presence of the transgene did not decrease the overall adult fitness for mass rearing and potential use in an SIT program.
Technical Abstract: Eight transgenic strains of Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae) were compared with the wild-type parental laboratory strain (P95) in colony. Measurements of average weight of pupae, percentage of adults emerging from pupae, ratio of males to total emerged adults, and mating competitiveness were analyzed. The parental strain colony was subcultured and exposed to handling procedures equivalent to transgenic strains for valid comparison of overall colony fitness. None of the transgenic colonies exhibited significantly lower fitness characteristics than the control parental colony, although one transgenic colony had a significantly higher ratio of adults emerging from pupae, and five colonies had significantly higher average pupal weight. Males of one transgenic strain were shown to mate with equal frequency when compared to males of the parental strain. Hence the presence of the transgene used to produce the strains tested did not incur a fitness cost to the colonies of laboratory-reared C. hominivorax.