Spatial distribution of genetic variability in the New World screwworm fly from the Caribbean and South America

The New World screwworm (NWS) fly, Cochliomyia hominivorax, is an obligate ectoparasite of a wide range of hosts in the Americas, from wildlife to man, but it is more notorious when affecting livestock. This species represents a serious threat to the livestock sector, it is necessary a continuous investment for this pest control. A key point in the design and implementation of an Area-wide integrated pest management control program is the identification and characterization of geographic populations, which might be assessed through genetic variability analysis. In this work, partial sequences of the mitochondrial genome (COI, COII and A+T-rich region) were used to investigate the genetic diversity in individuals from 54 geographic populations from South America and the Caribbean. These results showed high haplotype diversity values and moderate levels of mitocondrial nucleotide variability for this species. A complex pattern of population diversity distribution was found, with high and significant population structure in the Caribbean region, in contrast to a low population structure founded in South America. These results, suggest that several processes could be acting in the formation and maintenance of the genetic distribution pattern, which have different implications for the establishment of control programs for NWS in the different regions. Key words: Cochliomyia hominivorax, mitochondrial DNA, genetic variability, population structure and pest control. Financial support: Capes, CNPq, FAPESP, IAEA.