Stable fly, Stomoxys calcitrans (L.), dispersal and governing factors

Authors: Showler, Allan; Osbrink, Weste

Submitted to: International Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/23/2015
Publication Date: 5/27/2015
Publication URL: http://handle.nal.usda.gov/10113/61823
Citation: Showler, A.T., Osbrink, W.L.A. 2015. Stable fly, Stomoxys calcitrans (L.), dispersal and governing factors. International Journal of Insect Science. 7:19-25.

Interpretive Summary: Stable fly, mainly a pest of livestock, movement has been studied but it has not been presented on the various scales on which it occurs. On the local scale, most movement occurs between host animals and at resting sites where herbivorous livestock regularly congregate. Long distance dispersal is mainly wind-driven, carrying stable flies up to 225 km. Such movement is passive and does not appear to be advantageous to stable fly survival. Population expansion across much of the globe likely occurred from the late Pleistocene to the early Holocene in association with the spread of domesticated nomad livestock and particularly with more sedentary, penned livestock.

Technical Abstract: Although stable fly, Stomoxys calcitrans (L.), movement has been studied, its extent and significance has been uncertain. On a local scale (<13 km), fly movement occurs between host animals and at resting sites to feed and mate, mainly at on-farm locations where herbivorous livestock regularly congregate. Small numbers emigrate from livestock congregation sites in search of other hosts and oviposition substrate, mostly within <1.6 km. Such local movement occurs by flight "90 cm above-ground, or with moving livestock. While stable flies are active year-round in warm latitudes, cold winters in temperate areas result in substantial population and activity declines, limiting movement of any sort to warmer seasons. Long distance dispersal (>13 km) is mainly wind-driven by weather fronts that carry stable flies from inland farm areas for up to 225 km to beaches of northwestern Florida and Lake Superior (this might occur elsewhere but it has not been reported). Stable flies can reproduce for a short time each year in washed-up sea grass, but the beaches are not conducive to establishment. Such movement is passive and does not appear to be advantageous to stable fly survival. On a regional scale, stable flies exhibit little genetic differentiation, and on the global scale, while there might be more than one "lineage," the species is nevertheless considered to be panmictic. Population expansion across much of the globe likely occurred from the late Pleistocene to the early Holocene in association with the spread of domesticated nomad livestock and particularly with more sedentary, penned livestock.