Breeding‐site productivity of the swamp forest mosquitoes Mansonia bonneae and Ma.dives in Sarawak, East Malaysia

Abstract

Studies on larval population densities and adult emergence rates of the Brugian filariasis vectors Mansonia bonneae Edwards and Ma. dives Schiner were conducted in freshwater swamp forest bordering the Sadong River, Serian District, Sarawak, East Malaysia, during 1984-85. Three species of aquatic host-plants in the Family Araceae were identified as supporting immature stages of the Ma. bonneae/dives complex. Proportions of positive plants were 4.7%, 6.5% and 3.4% with 6.4 +/- 2.6, 7.3 +/- 2.8 and 10.1 +/- 1.1 larvae per positive plant, respectively, for the plant species Homalomena cordata Schott, H. rostrata Griffiths and Hydrostemma motleyi (Hook. f.) Mabberley. These data indicate no significant preferences between the three types of host-plant. Detailed monitoring of the host-plant H. cordata revealed no significant monthly fluctuations in larval density per plant nor the proportion of positive plants. 11.6% of larvae were Ma. dives and 88.4% were Ma. bonneae. Mean daily yields of Ma. bonneae/dives adults per square metre of H. cordata vegetated water surface were 0.45 males plus 0.57 females during the wet season (December-February) compared with 0.2 males plus 0.31 females during the dry season (June-August). Thus output of adults per plant was approximately halved, and suitable breeding areas were further reduced, during the dry season. By extrapolation from these rates, a crude mean estimate for productivity of Ma. bonneae/dives females is 1.6 million per hectare per annum in swamp forest habitats vegetated with any of the host-plants studied.

Effect of expanding farmlands with domestication of animals in the vicinity of disturbed swamps and built-up farmland ponds on population dispersion and decline of locally adapted Mansonia vectors (Diptera: Culicidae)

“…dives (Schiner) are known to be natural vectors for Malayan filariasis caused by the nocturnal sub-periodic B. malayi in endemic countries in Southeast Asia, including Indonesia [5,16,17], Malaysia [6,7,[18][19][20], and Thailand [21][22][23][24]. Previous studies demonstrated that certain Mansonia exophilic species exhibit endophilic hematophagy, particularly when expanding human populations invade their natural habitats, particularly in B. malayi endemic villages in the vicinity of swamps [4,7,9,10,[16][17][18][19]24]. Among these Mansonoides mosquitoes, Ma.…”

Simulated field studies with three formulations ofBacillus thuringiensisvar.israelensisandBacillus sphaericusagainst larvae ofMansonia bonneae(Diptera: Culicidae) in Sarawak, Malaysia

“…other south-east Asian countries (Chang et al, 1988;Wharton, 1962). Its larvae attach themselves to the roots Mansonia bonneae Edwards, the principal vector of of a wide range of aquatic plants with their modified ressubperiodic brugian filariasis, breeds extensively in piratory siphon to obtain oxygen.…”

Comparative transmission potential of three Mansonia spp. (Diptera: Culicidae) for filariasis in Sarawak, Malaysia

“…in Sarawak is scanty. Recently, Chang et al (1988) studied the larval habitats of M. bonneae and M. dives, but, to date, there are no comprehensive studies on the bionomics and biology of adult Mansonia spp. The objective of the present studies was to gather the entomological parameters with reference to species composition, seasonal abundance, biting activity, survival rate and natural infection rate of B. malayi in wild-caught Mansonia spp.…”