Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/1997
Publication Date: N/A
Interpretive Summary: The horn fly, Haematobia irritans, is an important economic pest of livestock. The pest spends all of its life on the host feeding multiple times over a 24-hour day. Horn flies are becoming resistant to many of the pesticides commonly used for their control. Basic studies to develop information about their feeding mechanisms and habits could lead to control lprocedures not requiring the use of the classical pesticides. These studie identified some characteristics about the diversity of the salivary secretions at feeding which allows the fly to take a blood meal. Also, the horn fly produces reduced amounts of salivary proteins as compared to those flies feeding at 3-4 day intervals. Hopefully, this information can lead to the development of novel or different approaches to control this pest.
Technical Abstract: The economic impact on livestock production by Haematobia irritans (Linnaeus) is estimated to approach one billion dollars/year in North America. However, there is little information regarding the blood-feeding strategy employed by these insects. Information presented shows that horn fly saliva interferes with the normal coagulation response as measured by the recalcification time assay. The relative anticoagulant activity on a per gland basis was equal to or greater than that reported for Simulium vittatum Zetterstedt, a common hematophagous black fly that also feeds on cattle. However, unlike S. vittatum, H. irritans salivary factors do not inhibit platelet aggregation using apyrase and have no detectable vasodilative activity. In this regard, the horn fly is strikingly different from blood-feeding species in the lower Diptera and shows a much more limited repertoire of antihemostatic factors.