Abstract:
Biological control of vector mosquitoes is a very important concept in
mosquito control programmes. Predatory mosquitoes are the most
important biological control agents as they usually coexist with other
mosquito larvae especially in natural habitats compared to urban or semi
urban habitats. A survey on predatory mosquito larvae associated with
vector mosquitoes was carried out in Galle District of the Southern
Province of Sri Lanka. All potential breeding habitats of Aedes albopictus
such as domestic and peri-domestic water storage containers, cement tanks,
ponds, ditches and overhead tanks were examined in 100 premises in
selected sites in Thitthagalla area, Galle. The containers which were
positive for predatory Lutzia (Metalutzia) fuscana with vector Ae. albopictus
larvae were recorded. The container index for both species were calculated
and species identification of the collected mosquitoes was confirmed in the
laboratory using standard taxonomic keys for mosquito adults and larvae.
Weather data during the sampling periods were also recorded. Container
indices of water storage cement tanks and tyres for L. fuscana were 50%
and 32% while the respective values for Ae. albopictus larvae were 50%
and 72%. L. fuscana larvae in cement containers showed positive linear
correlation with temperature (r= 0.713, P<0.01), a negative linear correlation
with relative humidity (r= -0.419, P<0.01) and but no linear correlation
with the rain fall (r= -0.200, P>0.05). Predatory potential of L. fuscana
needs to be studied further for effective biological control of Ae. albopictus
larvae in Galle district.
