Characterization of apyrase-like activity in Ochlerotatus triseriatus, Ochlerotatus hendersoni, and Aedes aegypti.

The saliva of a blood-feeding insect can facilitate the intake of blood and effect the transmission of a pathogen. Apyrase is a salivary enzyme that inhibits the aggregation of platelets by hydrolyzing the activating molecule ADP. Apyrase also hydrolyzes ATP, which is a signal for neutrophil activation. Investigators have reported that malaria vector species in the Anopheles gambiae species complex and the genus Simulium had more apyrase activity than sibling species that were non-vectors. In this study, salivary gland extracta from sibling species Ochlerotatus triseriatus (Say), vector of LaCrosse virus, and the non-vector Oc. hendersoni Cockerell were examined. Apyrase activity was characterized from both species, but no difference in activities was observed. Differences in days to maximal apyrase activity after eclosion and apyrase levels after a blood meal were detected between Oc. triseriatus and Aedes aegypti L. (Rockefeller strain). These differences indicate that Ae. aegypti may be able to feed sooner and more often than Oc. triseriatus.