[Comparison of rDNA-ITS2 sequences and morphological characters of Anopheles kunmingensis and Anopheles langshanensis in China, with discussion on taxonomic status].

OBJECTIVE: To determine the taxonomic status of Anopheles kunmingensis (AK) and An. liangshanensis(AL) from China. METHODS: Sequence differences of rDNA-ITS2 and main morphological characters variability between different sources of AK and AL were compared. RESULTS: The level of rDNA-ITS2 sequence differences among eight samples was under 2.9%. The total occurrence rates of main morphological characters examined in the female mosquitoes with pale fringe spot on V5.2, white basal band (or spot) on hind tarsomere IV, and larvae with bifurcated head hair 2-C were 43%(9/21), 89%(17/19), 40(4/10) in AK, and 79%(34/43), 44%(17/39), 20%(4/20) in AL, respectively. These rates calculated from separate colonies fluctuated within a wide range and overlapped, suggesting that there was no definite, stable morphological difference between AK and AL. CONCLUSION: The morphological and molecular variations between AK and AL were small and belong to intraspecific level. The AK and AL may be considered as the same species, and that the An. kunmingensis may be recognized as the synonym of An. liangshanensis.

[Predictive impact on malaria prevalence by hydraulic project of three gorges of the Yangtze River].

Malaria had a wide distribution and high prevalence throughout the Three Gorges region of the Yangtze River. After antimalarial program, its incidence rate was reduced to 2.2% in 1985, but sporadic cases still occurred in 34.7% of the townships and local outbreaks were not uncommon. Therefore, potential factors of malaria outbreak are still present. It is predicted that maximum risk of malaria outbreak will take place, during construction and after the completion of the reservoir, the breeding sites of Anopheles would be extended to irrigation network, low-lying of flooded land, and malaria prevalence might be increased.