Resting behavior and malaria vector incrimination of Anopheles stephensi in Goa, India

Malaria in Goa, India, has been endemic ever since an outbreak occurred in 1986. Anopheles stephensi Liston has always been suspected as a malaria vector in this area. Due to lack of knowledge on its resting behavior, sufficient adult females could not be collected and incriminated as vectors in the past. In this study mosquito collections were conducted in three endemic urban and suburban areas of Goa. In well-built houses, 67 h of collections did not yield a single An. stephensi mosquito, although other species were encountered. However, collections in construction sites and workers' huts for 151 h yielded, besides other mosquito species, 38 An. stephensi females resting in 15 types of sites at a height varying from 30 cm to 2.4 m. Of the 37 of these mosquitoes tested for the presence of circumsporozoite protein (CSP) by an ELISA technique, 1 was found to be Plasmodium falciparum CSP positive.