ABSTRACT
During 1984 to 1986 mosquito surveys were conducted in Tamwe Township to determine factors which influence the abundance of Aedes aegypti in rainy season in Yangon. Both the biological and environmental factors were studied. Increase in the hatchability of egg, larval survival rate and the shorten larval life span and increased pupation rates supplemented by rainfall (i.e. continous flooding of the containers stimulate the continuous hatching of eggs which laid on the inside walls of the containers) were observed to be correlated with the increased in population density of Ae.aegypti during the raining season in Yangon.
Subject(s)
Aedes , Entomology , MyanmarABSTRACT
The efficacy of aquarium fish Trichogaster trichopterus as a larvivorous fish was tried out in the laboratory and its predatory rate was found to be 1269 larvae per 24-hour exposure in glass bowl with 1.5 litre of water. Based on this finding a small scale field trial was carried out domestic containers including metal drums, glazwd earthern jars, and concrete tanks with Aedes aegypti breeding in Ngadatkyi North Qr., Bahan. The results show that this fish is an efficient biological larval control agent in domestic water containers.
Subject(s)
Cyprinodontiformes , Lava , MyanmarABSTRACT
During exploratory survey by Medical Entomology Research Division, Department of Medical Research to select areas for anopheline ecology studies, Tha-bye-wa village, Oktwin Township, Bago Division was found to have a very high malaria parasite rate and also high vectors density as well as a rich mosquito fauna. The results of survey carried out in momsoon season and in the cool/dry season were compared and the epidemiological situation discussed.
Subject(s)
Malaria , Seasonal Affective Disorder , MyanmarABSTRACT
Anopheles minimus is a common anopheline species in Myanmar, especially in the forested foot -hill areas. During routine survey many variations in adult morphology were noted. Iso-female lines were raised from wild-caught female and the morphological variations in F1 adults were studied. At the same time the identification of specimens was confirmed by detailed examination of larval skin slides. A guide for field workers on identification of An.minimus was also presented.
Subject(s)
Anopheles , EntomologyABSTRACT
Anopheles maculatus was found to be distributed in association with forested foot-hills. In some areas of Myanmar this species could be collected in very high densities. This species could be regarded as a possible vector of malaria in Myanmar. Epidemiological evidences and laboratory infection study results were presented. The presence of different sibling species of An. maculatus based on morphological characters was also presented.
Subject(s)
Anopheles , Culicidae , MyanmarABSTRACT
The larvicidal efficacy of Bacillus sphaericus -2362 and 2297 was tested against larvae of Anophales Dirus (Mudon strain) and Anophales annularis (DDT-resistant strain from Sittwe), using the method of Dubitskij (1) with some modifications. The results showed that although both the strains of B.sphaericus were effective larvicides, strains 2363 was found to be much more potent than strain 2297. Anopheles dirus was also found to be more susceptible than An.annularis. Larval cadavers were found to play an important role in the maintenance and recycling of B.sphaericus-2362.
Subject(s)
Bacillus , Xylariales , AnophelesABSTRACT
Malaria workers in Myanmar have only recorded the prevalence of Anopheles philippinensis in the country and anopheles nivipes have not yet been identified in Myanmar. The Department of Medical Research (DMR) survey teams to Tha-bye-wa, Oktwin Township collected many specimen provisionally identified in the field as An. philippinensis. Iso-female lines were raised from wild caught female to preparelarval skin, pupal skin and adult specimens for detail morphological examination. The specimens collected from the forested foot-hill area of Tha-bye-wa was found to be An. nivipes, which was recorded for the first time in Myanmar. The distribution,seasonal prevalence, adult bionomics and larval habits for both species, as described by previous wprkers were compared with the observations of the DMR survey teams.
Subject(s)
Anopheles , Culicidae , Malaria , MyanmarABSTRACT
Anopheles annularis, a very common anopheline mosquito in Myanmar, was studied in detail by survey teams of the Department of Medical Research. Field survey results were presented and compared with the finding of previous workers. Laboratory studies on DDT resistances, genetics of DDT resistance, comparison of two strains and laboratory colonization were described and the results presented.
Subject(s)
Anopheles , Malaria , MyanmarABSTRACT
Entomological survey was carried out during July 1987 in a forestedfoot hill teak plantation area Tha-bye-wa village, Oktwin Township, Pegu Division. At the same time, thick and thin blood films were taken and spleen rate determined in children. The parasite rate for children under 10 years of age was 66.7
(16/24) and the infant parasite rate was 50
(2/4). The spleen rate for children 2-9 years age group was found to be 88.2
(15/17). The anopheline fauna collected was mostly made up of An. dirus, An.minimus, An. tessalatus, An. minimus was found to have occysts and one An. vagus collected biting man had sporozoites in the salivary glands. Two species of mosquitoes were also recorded for the first time in Burma. The epidemiological pattern of malaria transmission in the area and possible methodologies for control in such areas are discussed.
Subject(s)
MalariaABSTRACT
Anopheles minimus together with Anopheles dirus consitute the primary vectors of malaria in Myanmar. The former has a wider distribution and occurs in higher densities with longer seasonal prevalence and is therefore considered to be the most important malaria vector in the country. Previous studies showed that An.minimus breeds in grassy edges of perennial hill streams, in slow running irrigation channels and terraced rice field while DMR teams, in addition, found it breeding in small puddles in stream beds together with An. maculatus. At Phado, An. minimus was found to constitute 26.2 per cent, 50.5 per cent and 44.1 per cent in monsoon, cool/dry hot/dry seasons respectively.Prevalence of An.minimus in relation to distance from forest was presented. Biting, resting behaviour and host preference studies were carried out and results presented. Man-biting rate and vectorial capicities in relation to rainfall for each month over a year are also presented.
Subject(s)
Anopheles , Culicidae , Malaria , MyanmarABSTRACT
Results of the study involving distribution, breeding habits, biology under laboratory cinditions, adult bionomics and its relationship to malaria transmission under different ecological condition have been studied and presented. Cytogenetics and iso-enzyme studies to differentiate its sibling species were also presented. Of the sibling species of An.dirus, species D was found to predominate in Myanmar, whereas species A was recorded from Central Burma. Susceptibility of An.dirus to DDT and Bacillus sphaericus was also reported.
Subject(s)
Anopheles , Culicidae , Malaria , MyanmarABSTRACT
During routine mosquito collections in a rice cultivation area near Yangon, one blood fed Aedes (Aedimorphus) nigrostriatus female was collected. It was allowed to oviposit and a colony was raised. Adult specimens, male teminalia slides, pupal and larval skin slides were prepared and preserved in the Department of Medical Research (DMR) collections. The morphological characters of the pupa and larva, currently unknown, are described in detail.