Estimates of Egyptian culcine longevity in nature altered by fluctuations in biting population density

Estimates of vectorial capacity [VC] depend upon longevity of mosquito field populations, and expected longevity is estimated from the parity rate of the population. Seasonal variation in parity rates confound estimates of longevity which may not reflect actual population survival but are induced by changes in the rate of emergence of female mosquitoes. By comparing parity rates and biting activity in natural population of 2 Culicine mosquitoes, Culex pipiens and Cx. antennatus, we found that parity rate was low in the beginning of the season and high at the end. Parity rate appeared least affected during the weeks with maximal daily biting activity. We conclude that estimates of VC are most accurately determined for the two vector species studied when mosquito biting activity is maximal

Heterozygote deficiency in natural populations of aedes caspius pallas from Egypt

Aedes caspius Pallas populations from the Mediterranean regions are genetically highly polymorphic, and may diverge into 2 genetically isolated forms. We examined the genetic structure of 3 mosquito populations from Faiyum oasis, using starch gel electrophoresis at 8 gene loci, from which only one was monomorphic. Genetic variability was high [A = 1.97; H = 0.12; P = 54.2, 66.7]. Eleven out of 16 population enzyme combinations with variability exhibited heterozygote deficiency from Hardy - Weinberg expectations. These results suggest that tested populations represent a mosquito complex, although no genetic divergence was detected [D = 0.012] since presumed sympatric gamodemes were sampled as a single population. It is of prime importance to detect cryptic gamodemes and to elucidate the present status of Ae. caspius, as this may greatly influence control strategies

colonization and biology of Egyptian culex univittatus [theobald]

Culex univittatus has been associated with several diseases in Egypt; however, its colonization procedures have not been described nor has its life cycle been studied in the laboratory. We found that all stages of this mosquito could be transported successfully over long distances in twilly bags stored in cooled water in a thermos. Immature stages survived well in distilled water and adult females fed on immobilized pigeon as well as giunea pigs and people. Fecundity was variable. Two third of eggs hatched when derived from the first gonotrophic cycle but this decreased in later gonotrophic cycles. Adult females were long lived and passed through several gonotrophic cycles. Blood feeding began one day after oviposition. Colonization will enable further study of this potential disease vector