Cytogenetic evidence for a species complex within Anopheles pseudopunctipennis theobald (Diptera: Culicidae).

Anopheles pseudopunctipennis was collected from Acapulco, Mexico and Sallee River, Grenada, West Indies and used in cross-mating experiments. Larvae from the cross, Mexico female X Grenada male, died in the third instar. However, adult progeny were obtained from the reciprocal cross Grenada female x Mexico male. These hybrid males had testes with apparently normal appearance but some without viable sperm. Polytene chromosomes obtained from hybrid females exhibited extensive asynapsis of the X chromosomes. Previously undescribed fixed inversion differences between the two populations were noted on the X chromosome. It is concluded that the two populations belong to different species. The Grenada population is designated An. pseudopunctipennis species C, since it is the third taxon recognized in this species complex.

A site receptivity study to determine to threat of the re-introduction and re-establishment of malaria in Grenada

Malaria was eradicated from Grenada in 1962 and the island has since remained free of the disease. However, it is well recognized that with the global resurgence of malaria in endemic areas, coupled with ever increasing international travel to Grenada from endemic areas, the threat of the reappearance of malaria in Grenada has never been greater. This prompted us to conduct this study to assess the risk of the re-introduction and re-establishment of malaria in Grenada. We surveyed the recorded historical breeding sites of Anopheles spp between April 1996 and April 1997, collected larvae and pupae from 75 sites throughout Grenada and raised them to adults for identification. Anopheles spp known to exist previously in Grenada, namely, A. aquasalis, A. argyritarsis, and A. pseudopunctipennis, were found to exist still in different densities, at different times of the year, and in different locations throughout the island. The highest Anopheles spp populations were found during the dry season and the Sallee and Antoine rivers were the most important breeding sites. These areas are not much frequented by tourists and commercial visitors. No Anopheles spp breeding sites were found near the main tourist or commercial areas. Vector control methods carried out earlier this century appear to have had a lasting impact in these areas. The results of this study indicate that the re-establishment of malaria as a serious public health problem is unlikely. The unfamilarity of diagnosis of malaria in this malaria free country, coupled with the presence of the vectors, mandates that malaria surveillance must be maintained, particularly since the government's spending on vector control activities has been reduced over the years.(AU)