DEVELOPMENT OF TOOLS FOR INTEGRATED PEST MANAGEMENT OF STABLE FLIES
Location: Agroecosystem Management Research
Title: Reproductive potential of stable flies (Diptera: Muscidae) fed cattle, chicken, or horse blood
Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 3, 2012
Publication Date: May 1, 2012
Citation: Friesen, K.M., Johnson, G.D. 2012. Reproductive potential of stable flies (Diptera: Muscidae) fed cattle, chicken, or horse blood. Journal of Medical Entomology. 49(3):461-466.
Interpretive Summary: Stable flies (Stomoxys calcitrans (L.)) are cosmopolitan pests of livestock, domestic animals, and humans. Both males and females blood-feed daily, and their painful bites may result in substantial economic loss, especially in the cattle industry. Although stable flies are often found in close proximity to poultry houses, the primary host source still appears to be cattle, indicating either an aversion of avian hosts or a preference for cattle. In fact, observations of stable flies attacking birds remains relatively rare. Furthermore, results from at least one study indicate that stable flies are not capable of successfully reproducing when fed chicken blood. However, during a West Nile virus outbreak in a colony of American white pelicans ((Pelecanus erythrorhynchos Gmelin) in northeast Montana, stable flies were found feeding on moribund pelicans en masse.
The objective of this investigation was to assess reproductive potential for lab-reared stable fly cohorts fed cattle, chicken, or horse blood. Stable flies fed chicken blood oviposited more eggs per day than did cohorts fed cattle or horse blood, but variance in oviposition periods resulted in equal lifetime fecundity across treatments. Although egg viability and maternal investment were higher in cohorts fed cattle blood, the differences from cohorts fed chicken and horse blood are probably not biologically significant. This is the first report of stable flies being able to develop viable eggs when fed avian blood. Stable flies may have fed on moribund pelicans because they were a relatively low risk host. Current general consensus seems to be that stable flies do not feed on birds primarily due to host-defensive behavior. However, this is mostly speculation, and to validate this, more extensive investigations should be conducted examining stable fly-host relationships. A further understanding of the behavioral physiology of stable flies may lead to new methods of control.
Reproductive potential was assessed for lab-reared stable fly cohorts fed cattle, chicken, or horse blood. Stable flies fed chicken blood oviposited more eggs per day than did cohorts fed cattle or horse blood, but variance in oviposition periods resulted in equal lifetime fecundity across treatments. Females reared on chicken blood laid an average of 24 eggs per day for 14 days. Groups fed cattle blood laid 20 eggs per day for 21 days and those fed horse blood laid 18 eggs per day for 17 days. Eggs produced by chicken blood-fed flies were smaller (.016 mm3 for chicken blood vs. 0.18 mm3 for cattle blood and 0.19 mm3 and horse blood) while eggs produced by horse blood-fed flies were less viable (59% hatch for horse blood vs. 83% for cattle blood and 94% for chicken blood). When egg viability was considered in addition to the number of eggs that were oviposited, lifetime reproductive potential was almost twice as high for flies fed cattle (323) and chicken blood (317) than for flies fed horse blood (172). Maternal investment, which took egg production and volume into account, was higher in cohorts fed cattle blood (70 mm3) when compared to the other treatments (chicken = 54 mm3, horse = 55 mm3). Implications of these findings for the behavioral ecology of stable flies are discussed.