[Comparison in susceptibility of Anopheles dirus and Anopheles stephensi to B strain of Plasmodium cynomolgi].

ABSTRACT

This paper reports on the comparative susceptibility of A. dirus (Hainan strain) and A. stephensi (Hor strain) to the B strain of P. cynomolgi in paired feeding experiments. In the most susceptible infective period, the infection rate in midgut and salivary gland of the two species was over 90%, the difference is not statistically significant. In relatively infective period, three experiments were performed, the infection rate in midgut of A. dirus was 24.4-60.4% with an average of 46.5% (53/114), and that of A. stephensi was 11.5-21.1% with an average of 14.2% (16/113). Statistically, experiment I showed no significant difference, the difference in experiment II was highly significant (P less than 0.01), and that in experiment III was significant (P less than 0.05). The number of oocysts in A. dirus was three times over that in A. stephensi. The infection rate of salivary gland in A. dirus was 18.2-55.0% with an average of 30.6% (19/62) and that of A. stephensi was 6.7-14.3% with an average of 9.5% (6/63). Statistically, only one of the three experiments showed significant difference (P less than 0.01). The result suggests that the susceptibility of A. dirus is higher than that of A. stephensi to the B strain of Plasmodium cynomolgi.