Studies on age groups within activity cycles, age composition and survivorship in natural populations of Mansonia in Kampung Pantai, Bengkoka Peninsula of Sabah state have been described. Early activity of 3-5 parous Ma. bonneae during the first hour after sunset was noted. Age composition of Ma. bonneae at forest shade, indoor and outdoor of house, comparative buffalo vs human bait outdoor in Kampung Pantai showed all round high parous rates ranging from 66.7 to 75.4%. Population 3-parous and older ranged from 18.8 to 26.7%. Nine of the 14 infective Ma. bonneae were 3-parous and this segment of the population was engaged in active transmission. High parous rates were observed in Ma. dives and Ma. uniformis taken in small numbers. Parous rates of Ma. bonneae taken in Kampung Delima and Kampung Taradas were also high. Estimates of daily survivorship of Ma. bonneae and Ma. dives determined by two methods were very high.
Bacillus thuringiensis israeliensis (BTI) against culicine mosquitoes was tried out in cement sullage drains in Kelang municipal area at a dosage of 0.15 ppm. and 0.6 ppm. The results of the trial showed that at 0.15 ppm. the BTI was not effective, but at 0.6 ppm. it was effective giving about 95% kill. There was no residual effect and treatment had to be repeated weekly.
1. A total of 8 samples from three natural populations and a laboratory strain of Aedes albopictus were analysed for glycerol-3-phosphate dehydrogenase phenotypes by means of horizontal starch-gel electrophoresis. 2. The electrophoretic phenotypes were governed by three codominant Gpd alleles. 3. There was low variability, with the heterozygosity in the variable samples ranging from 0.02 to 0.12. 4. The commonest allele in all the population samples was GpdB which encoded an electrophoretic band with intermediate mobility. 5. There was no temporal or spatial variation.
A strain of Clostridium bifermentans individualized as serovar malaysia (C.b.m.) according to its specific H antigen is toxic to mosquito and blackfly larvae when given orally. The toxicity occurs in sporulated cells which contain, in addition to spores, proteinic parasporal inclusion bodies and feather-like appendages; the amino acid content of the inclusion bodies is similar to that of Bacillus thuringiensis serovar israelensis (B.t.i.) and B. sphaericus crystals. The toxicity to Anopheles stephensi is as high as that of B.t.i. and the best strains of B. sphaericus. Culex pipiens is somewhat less susceptible, and Aedes aegypti much less. Pure parasporal inclusion bodies, isolated by ultracentrifugation on sucrose gradients, are highly toxic to mosquito larvae. The larvicidal power is destroyed by heating at 80 degrees C or by treatment with 50 mM NaOH. It is preserved by freeze-drying. The innocuity to mice of the sporulated cells is shown by different routes of administration: force-feeding, percutaneous, subcutaneous, intraperitoneal or intravenous injections. The potential for the biological control of mosquito and blackfly larvae is suggested.
1. Three natural populations and a laboratory strain of Aedes albopictus were analysed for glucose phosphate isomerase by means of horizontal starch-gel electrophoresis. 2. The electrophoretic phenotypes were governed by five codominant Gpi alleles. 3. The commonest allele in all the four population samples was GpiC which encoded an electrophoretic band with intermediate mobility. 4. The distributions of GPI phenotypes were in accordance with Hardy-Weinberg expectations. 5. The four population samples could be differentiated by the presence of a unique Gpi allele or the absence of a particular Gpi allele.
Methods are described for the laboratory colonization of Coquillettidia crassipes. The highest rate of insemination occurred in 60 x 60 x 120 cm cages and better insemination in laboratory adapted F15 generation. Embryonation and hatchability of eggs ranged from 69.6 to 97.9% and 63.3 to 94.3% respectively. Gravid females laid egg rafts on water in 500 ml breakers with small leaves of Salvinia for resting. Newly hatched larvae were set up in a basal medium of guinea pig dung and water or liver powder, yeast powder and water. Larvae attached to aquatic plants or 'Keaykolour' ruffia snow white paper. The cultures with paper gave better yields. At present 21 generations of Cq. crassipes have been reared in the laboratory.