Determining host selection of the stable fly, Stomoxys calcitrans (Linnaeus 1758), through bloodmeal analysis at a Texas wildlife park

The stable fly, Stomoxys calcitrans (Linnaeus 1758), is a serious pest of animals worldwide, particularly large ungulates and canids. These blood-feeding dipterans are of African origin and negatively affect domesticated livestock and wildlife systems. It is estimated that stable flies cost US cattle producers $2 billion per year, as cattle are the primary hosts in agricultural settings. It is unknown how the behavior or feeding patterns of this fly might change when presented with other host options, particularly exotics, including those found in its native African range. To address this question, we used molecular tools to examine host bloodmeals from stable flies collected at a drive-through safari park in Bryan, Texas. The park was divided into eight collection zones: three drive-through pastures with various species of birds and hoofed mammals, a zebra pasture, a quarantine/holding paddock area, and three walk-around zoo areas containing a wider variety of animals. Adult flies were collected weekly from May 2022 to May 2023, and DNA was extracted from whole body specimens collected across these zones. These DNA templates were used in a PCR assay targeting the vertebrate mitochondrial 16S gene. Resulting amplicons were submitted for Sanger sequencing and compared to publicly available data (NCBI) using BLAST. Searches indicated that the collected stable flies fed on a variety of hosts including but not limited to Bos grunniens (yak), Bos javanicus (banteng), Bos taurus (cattle), Dama dama (European fallow deer), Rucervus duvaucelii (barasingha), Taurutragus oryx (common eland), and Homo sapiens (human).