Search PubMed⌕ Search

Biomedical subjects

J Conn

Publications and source records attributed to J Conn.

69 records · Page 4Linked to original sources
PubMedDate not supplied

Population differentiation of the malaria vector Anopheles aquasalis using mitochondrial DNA.

Populations of the malaria vector Anopheles aquasalis from Venezuela, Trinidad, and Brazil were analyzed using restriction enzyme digestion of mitochondrial DNA (mtDNA). The five enzymes surveyed yielded 12 mtDNA haplotypes. Three restriction endonuclease profiles (Bcl I, Eco RI, and Hind III) differentiated the Venezuelan and Trinidadian A. aquasalis from two Brazilian populations. Estimates of mtDNA sequence divergence between the Venezuelan/Trinidadian populations and each Brazilian population (0.023-0.032), as well as divergence between the two Brazilian populations (0.030), were within the range of interspecific distances calculated for members of anopheline species complexes. Ribosomal DNA (rDNA) restriction profiles of the A. aquasalis populations examined were identical.

Animals↗
PubMedDate not supplied

Fecundity, parity, and adult feeding relationships among Nyssorhynchus malaria vectors from Venezuela.

Relative to their pre-engorgement weights, nulliparous Anopheles nuneztovari consumed significantly smaller blood meals than A. marajoara, A. triannulatus or A. aquasalis. When females were deprived of sugar before blood feeding, only one-quarter of A. nuneztovari, but more than two-thirds of A. marajoara, A. triannulatus and A. aquasalis matured eggs. Sugar feeding before blood, or two successive blood meals by sugar-deprived females, increased the proportion of nulliparous A. nuneztovari which developed eggs, but not significantly so. Nearly all individuals of nulliparous, sugar-fed A. marajoara, A. triannulatus and A. aquasalis matured eggs after one blood feeding. Among A. nuneztovari, A. marajoara and A. aquasalis that matured some eggs in the laboratory, there were no positive correlations between the number of eggs developed and relative blood meal size. However, blood meals larger than the mean size significantly increased the chance that A. nuneztovari would develop some eggs. Mean fecundities of gravid A. nuneztovari and A. marajoara reared in the laboratory were significantly lower than those of the same species captured at human bait in nature. Post-engorgement access to sugar by A. nuneztovari (captured at human bait) did not influence fecundity, but significantly enhanced survivorship and the proportion of individuals which retained eggs. Release-recapture experiments revealed that relatively small blood meals are typical of A. nuneztovari only during the first gonotrophic cycle. We suggest that multiple blood feeding, seemingly necessary for most A. nuneztovari to develop a first clutch of eggs, may increase the probability of infection with Plasmodium vivax where this mosquito species is a primary vector.

Animals↗
PubMedDate not supplied

Life history correlates of adult size in the malaria vector Anopheles darlingi.

Adult dry weights of laboratory-reared Anopheles darlingi were highly correlated with wing lengths, which were used to estimate size variation in natural populations of this species. Significant differences in mean wing lengths of females trapped at baits were detected among collections in the same week at one site, but not between three sites in Brazil and Bolivia. Relatively higher variability of wing lengths, compared to collections of other Anopheles (Nyssorhynchus), and platykurtic size distributions in large, single-night collections suggested that An. darlingi females caught at baits emerged from heterogenous larval habitats. No relationship was detected between parous state and the body size of wild-caught females. Adult males and females of laboratory-reared An. darlingi did not differ in body size. This absence of sexual size dimorphism is rare among mosquitoes and has not been noted previously in the genus Anopheles.

Animals↗