Life history metrics for Culex tarsalis (Diptera: Culicidae) and Culicoides sonorensis (Diptera: Ceratopogonidae) are not impacted by artificial feeding on defibrinated versus EDTA-treated blood

Authors: Swanson, Dustin; McGregor, Bethany

Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/6/2022
Publication Date: 11/2/2022
Citation: Swanson, D.A., McGregor, B.L. 2022. Life history metrics for Culex tarsalis (Diptera: Culicidae) and Culicoides sonorensis (Diptera: Ceratopogonidae) are not impacted by artificial feeding on defibrinated versus EDTA-treated blood. Journal of Medical Entomology. 60(1):224-227. https://doi.org/10.1093/jme/tjac171.
DOI: https://doi.org/10.1093/jme/tjac171

Interpretive Summary: One important consideration when rearing blood-feeding insects in the laboratory is the blood source that will be used. Artificial blood-feeding methods, in which blood is collected prior to the feed and given to the insects through an artificial feeding system, are common and avoid the need for feeding on live animals in the laboratory. This blood must be treated to prevent clotting, and this anticoagulation can be achieved through chemical or mechanical methods. However, we don't know what impact different types of anticoagulation methods have on traits in some blood-feeding insects. In this study, we compared one mechanical method (defibrination) in which clots are physically removed from the blood with a chemical method (K2 EDTA) in which a chemical reaction prevents clotting in two vectors-one mosquito species (Culex tarsalis) and one biting midge species (Culicoides sonorensis). Traits that were studied included the rate of blood feeding, amount of blood ingested, mortality, number of eggs laid, and egg hatch rate. We found that there was no difference between these two anticoagulation methods in any of the traits. This result means that both blood anticoagulants can be used with these two vector species without causing negative impacts on study outcomes.

Technical Abstract: Artificial blood feeding is a common practice for the study and maintenance of blood feeding arthropod colonies. Commercially purchased blood is often treated to prevent clot-formation using either mechanical or chemical means. For many hematophagous insects, the effect that different anticoagulation methods may have on life history metrics is unclear. In this study, Culex tarsalis (Diptera: Culicidae) and Culicoides sonorensis (Diptera: Ceratopogonidae) were fed blood treated with either mechanical (defibrination) or chemical (K2 EDTA) anticoagulation methods. Several blood feeding and life history metrics were evaluated between treatment groups including blood feeding rate, blood volume ingested, fecundity, fertility, and mortality. No significant differences were found for any of the measured life history metrics for either species. For experiments measuring aspects of these blood feeding and life history traits, blood treated using either defibrination or K2 EDTA anticoagulants should not impact experimental outcomes based on this study.