The effects of salt on the development of Aedes togoi and the infecton of Brugia pahangi were studied. Salt concentrations over 7.2% completely got rid of pupae and adults. The salt concentrations 0% to 3.6% reduced pupal development from 86.6% to 72.8% and adult from 70.3% to 53.3%. B. pahangi infestations and infection rates were also reduced in the mosquitoes reared at salt concentrations of 1.8% and 3.6%. Trends of retardation in the filarial development were observed when the salt concentrations were increased.
parasitology-arthropoda ; Aedes togoi ; nematoda-Brugia pahangi ; salt ; development

A study on the Aedes togoi to find out important biological and ecological factors as an efficient vector of filariasis, was carried out on Che-Ju Island for two years from 1968 though 1969. Results obtained are as followings: Geographical distribution of the mosquito breeding habitat was found to be extensive covering circular areas of about three km distance along the shore line. The main breeding sites were rockpools and smaller holes on rocks retaining tide and/or rain water with high larval density; water tanks, pots, and other artificial containers retaining only rain water around the houses located within the area with relatively low larval density. Species constitution of adult mosquitos collected in the study villages consisted largely of Aedes togoi with a range of 70-90 per cent by village. The pH of the breeding sites ranged from 5.0 to l0.0, and the chloride content from 0.01 to 28.75 (gm/l). More than fifty per cent of examined sites, however, had pH 5.6-6.5 and chloride content of less than 1.0 gm/1. The natural infection rate of A. togoi by filaria showed proportional relationships with microfilaria rates among the human population by area. Experimental infection of A. togoi by human and dog filaria demonstrated that this species is an efficient vector for both filaria species proved by natural infection as well as experimental infection. Susceptibility of both larva and adult of A. togoi to insecticide, DDT and dieldrin, showed considerable sensitivity in all villages tested.
parasitology-arthropoda ; vector ; Aedes togoi ; epidemiology ; filariasis ; Brugia malayi ; chloride

In filariasis the infectivity of the appropriate mosquito vector is not consistent with the microfilarial density of the host. The reason may be attributed such factors as the time of microfilarial appearance in the peripheral blood of the host, the time of maximum biting activity of the arthropod vector, or the morphological adaptation of the feeding mechanism of the vector. However, it is quite puzzling to see why the number of microfilariae taken up by mosquitoes is subjected such a great variation, even though the same batch of mosquitoes are fed on the same filarial host under same laboratory conditions. The experiment was designed to observe more detail aspect of this relation. Adult Aedes togoi (Theobald, 1907) mosquitoes were reared from egg rafes colonized in an insectary. Animals used were Taiwan monkeys, Macaca cyclopsis which had been artificially infected with Wucheria malayi. The animals showed the microfilarial counts as low as nil to ten per slide of 20 cmm3 of blood, which seem to be rather fortunate for this kind of work. The microfilarial density of each animal was counted by taking each ten smears of 20 cmm(3) of peripheral blood the ear lobes before and after mosquito bite. Feeding were done in two occations, during 1600-1630 and 1900-1930 hours of the same day. The monkeys were immobilized and a rayon cage, housed 100 female mosquitoes for two days starvation, was exposed to the shaved abdomen of each animal. Fully engorged mosquitoes were transferred to a square rearing cage, which was later placed in the insectary, where kept temperature of 23-27degree C and relative humidity of 80-85 per cent. It was found that filarial larvae of the mosquito body usually develop to the third or infective stage in about 10 days after blood meal under these conditions. Daily dissections were made of these mosquitoes, either living or dead, after one week of rearing. Analysing of the result, the following conclusion was made. The rate and intensity of infection in mosquitoes are not directly related to the blood counts of microfilariae of the host animals. This is perhaps due to fluctuations of microbial outflow in the peripheral blood of individual animals. The reason of this would be no doubt due to a patch type of microfilarial distribution in the host blood.
parasitology-arthropodology-mosquito ; Aedes togoi ; Macaca cyclopsis ; monkey ; protozoology ; Brugia malayi ; microfilaria ; animal

Malayain filariasis in Korea is reviewed in the point of history, parasitology, epdidemiology, pathology and clinical aspects, diagnosis and chemotherapy.
parasitology-helminth-nematoda ; Brugia malayi ; filariasis ; epidemiology ; pathology ; clinical finding ; diagnosis ; chemotherapy ; diethylcarbamazine ; Aedes togoi