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ARS Home » Plains Area » Kerrville, Texas » Knipling-Bushland U.S. Livestock Insects Research Laboratory » Livestock Arthropod Pest Research Unit » Research » Publications at this Location » Publication #397980

Research Project: Integrated Pest Management of Flies of Veterinary Importance

Location: Livestock Arthropod Pest Research Unit

Title: Insights into the genetic landscape and presence of Cochliomyia hominivorax in the Caribbean

item Tietjen, Mackenzie
item PFEIFFER, VERA - Washington State University
item Poh, Karen

Submitted to: Parasitology Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/16/2022
Publication Date: 12/17/2022
Citation: Tietjen, M., Pfeiffer, V., Poh, K.C. 2022. Insights into the genetic landscape and presence of Cochliomyia hominivorax in the Caribbean. Parasitology Research. 122:547-556.

Interpretive Summary: The New World screwworm fly is a major economic burden to the livestock industry in the Caribbean. In order to better understand more specifically where these flies reside, GPS coordinates were collected and the associated environmental variables were examined. Also, to understand fly dispersal in the Caribbean, genetics was used to examine gene flow and how they are related across the landscape.

Technical Abstract: The New World screwworm, Cochliomyia hominivorax (Coquerel, 1858), is a major parasite that causes myiasis in livestock, humans, and other warm-blooded animals in the western hemisphere. There is a permanent biological border that is maintained between Panama and Colombia, as it has been eradicated from North and Central America. However, it still exists in much of the Caribbean and South America causing an estimated annual loss of $3.6 billion dollars in South America alone. Less information is available for C. hominivorax in the Caribbean. Thus, here we examined its presence and genetic landscape in order to gain insights into this fly’s dispersal in this region. First, through sampling efforts, novel GPS coordinates were collected. Second, the environmental correlates of those presence points were examined. Next, samples were sequenced in order to obtain a pairwise FIT genetic distance matrix. And lastly this matrix was used to create a genetic landscape of divergence. The results of the genetic landscape show flies as more diverse in Trinidad and Tobago and less diverse in the Dominican Republic. This is perhaps due to the proximity of Trinidad to Venezuela and gene flow may be occurring between these two areas. This information will aid in screwworm surveillance and control programs by providing environmental correlates and a view into the dispersal of these flies.