SALIVARY-GLAND ANTICOAGULANTS IN CULICINE AND ANOPHELINE MOSQUITOS (DIPTERA, CULICIDAE)

Female salivary gland extracts from 9 mosquito species representing th e 2 hematophagous subfamilies delayed coagulation of human plasma. All extracts significantly delayed recalcification time, prothrombin time , and activated partial thromboplastin time, indicating an effect on t he common coagulation pathway. Chromogenic assays to determine the coa gulation inhibition site were performed for coagulation factor Xa (FXa ) and thrombin, the major components of the common pathway. Although v ariation existed in the degree of inhibition, all anophelines have thr ombin-directed anticoagulants, and culicine mosquitoes have FXa-direct ed anticoagulants. Differences in the site of action of the anticoagul ants most likely reflected the long period of independent adaptation o f the 2 subfamilies to the challenges presented by vertebrate hemostas is.