以斯氏按蚊传代保种的约氏疟原虫(BY265株)接种小鼠后第3、4天感染大劣按蚊,涎腺感染率为4.88％,进腺子孢子数少于10个。约氏疟原虫经过大劣按蚊传代后,大劣按蚊的涎腺感染率明显增高。感染蚊传3、4、6和7代首次血传的疟原虫,涎腺感染率分别为31.7％(13/41)、70％(14/20)、6.9％(2/29)和30％(6/20)。以含有第6代子孢子的大劣按蚊叮咬小鼠,能使鼠获得感染,第7代疟原虫感染的大劣按蚊涎腺内子孢子数可超过2,000个。结果表明约氏疟原虫对大劣按蚊有逐渐适应的能力。 Anopheles dirus was infected on the 3rd and 4th days after inoculation of mice with Anopheles stephensi (BY265 strain). The infection rate of salivary glands was 4.88% and the number of gonadal spores was less than 10. After the P. yoelii passaged through Anopheles dirus, the infection rate of salivary gland in Anopheles dirus significantly increased. Infection with mosquitoes of the first, 3rd, 4th, 6th and 7th generations of mosquitoes infected were 31.7% (13/41), 70% (14/20), 6.9% (2/29) and 30% (6/20). Anaphylactis davidianus, which contains the 6th generation sporozoites, can infect mice. The number of sporozoites in the salivary gland of Anopheles stephensi infected with the 7th generation can exceed 2,000. The results indicate that Plasmodium yoelii has a gradual adaptability to Anopheles dirus.