BLOOD-ENGORGEMENT KINETICS OF 4 ANOPHELINE MOSQUITOS FROM TRINIDAD, WEST-INDIES

The blood-feeding kinetics of Anopheles albitarsis, An. aquasalis, An. bellator and An. homunculus were determined under laboratory conditio ns using females collected from two sites in Trinidad. Many An. aquasa lis, An. albitarsis and An. bellator completed probing within 30 s but An. homunculus averaged >50 s. Anopheles albitarsis (68.3 s), An. aqu asalis (67.0 s) and An. homunculus (77.7 s) took similar times to fill their guts but All. bellator took longer (106.5 s). More than 75% of the An. albitarsis, An. aquasalis and An. homunculus but only 51% of t he An. bellator showed apparent prediuresis. Anopheles aquasalis exhib ited the shortest mean duration of prediuresis (77.3 s) and An. homunc ulus the longest (152.9 s). Most individual mosquitoes spent less time filling their guts than in prediuresis. Overall, An. aquasalis exhibi ted the shortest total feeding time (135.7 s) and An. homunculus the l ongest (197.0 s). There was a considerable degree of variation among i ndividuals of each species in their ability to agglutinate human eryth rocytes immediately upon blood engorgement. For ex-ample, within the s ame feeding experiments, some individuals agglutinated <25% of the ing ested erythrocytes whereas others agglutinated greater than or equal t o 90%. The parity of the field-collected anophelines had no significan t effect on probing, duration of blood-feeding, duration of prediuresi s, or erythrocyte agglutination. The inter- and intra-specific variati ons in blood-feeding and erythrocyte processing observed for the four species of field-collected anophelines from Trinidad are discussed in terms of vector competence and the evolution of these behaviours.