大劣按蚊吸血活动与交配受精的关系

大劣按蚊Anophelos dirus是我国及东南亚地区的重要传疟媒介。研究表明成蚊羽化后,在未喂血的情况下,可有较高的交配受精率。在同一蚊笼,吸血机会完全相同的条件下,大蚊笼受精雌蚊吸血率为59.88%,未受精雌蚊的吸血率为35.38%;小蚊笼受精雌蚊的吸血率为74.13%,未受精雌蚊吸血率仅为43.56%。正常交配雌蚊的吸血率为49.71%,未进行交配的处女雌蚊吸血率为28.42%。同为正常交配蚊群,喂血组雌蚊受精率55.85%,不喂血组的受精率为44.51%。初步认为大劣按蚊的吸血活动与交配受精有一定的关系。

BLOOD SUCKING IN RELATION TO MATING RATE IN ANOPHELES DIRUS

Anopheles dims is an important vector of malaria in southeastern Asia and China, Previous studies on the. behaviour of this mosquito have revealed that the sex ration of 1 :1.5 was the best proportion for provoking mating process. Natural mating takes. place at least 48 hours after adult emergence and since then it would last -for 21 days. In the present work the influence of blood sucking on the mating rate of this species is studied and the results are summaried as follows:1. Mating rates were examined in females unfed with blood. Three experiments with the mosquitoes reared in large cages gave results showing the at mating rates were 72.97%, 73.56% and 89.77% on the sixth day after emergence respectively. For those reared in small cages the mating rates wore 37.50%, 47.27%, and 50.00% respectively on the seventh tiny after emergence. This confirms that the females unaceessible to blo-odmeal wonld still reach a rather high misting rate.2. Mosquitoes were reared in eages with equal opportunity to obtain bloodmeal . It was Found that in the large cage the rate of blood sucking was 59.88% tor the fertilized IVrnales and only 35.38% for Hie unfertilized females. In the small cage it was 74.13% for the fertilized females and 43.56% for the unfertilized females.3. A rabbit was used in two cages to feed the mosquitoes simultaneously. One cage-contained females accessible to mating and the other contained vergin females unaceessi-ble to mating, it was found that the rate of blood sucking was 49.71% for the females accessible to mating and only 28.42% for the virgin females.4. The rate of fertilization of females accessible to mating was 55.85% for the blood sucking group and 44.51% for the nonsucking group. The result implies that the activity of blood sucking may exert some influence on the mating rate of this mosquito.