The prevalence of the mosquito predator, Toxorhynchites splendens larvae along with its prey, Aedes albopictus larvae in Malaysia

Toxorhynchites splendens is a beneficial mosquito because it is predator to larvae of Aedes albopictus, a harmful vector disease. The objective of the study is to evaluate the prevalence of Tx. splendens larvae along with Ae. albopictus larvae in Malaysia. Our working hypothesis is higher number of Tx. splendens larvae in the containers will decrease the number of Ae. albopictus larvae and their existence is associated with temperature, relative humidity and rainfall. This study was carried out from July 2011 to June 2012 in two locations; woody and residential areas. The containers used in the study were tires, glass, tin cans and bamboo stumps. Every week, water and larvae were sampled from the containers in both locations and brought back to laboratory for identification. There was a negative correlation between the numbers of Tx. splendens larvae with the numbers of Ae. albopictus larvae occurred in the containers (R=-0.278, p<0.01), temperature (R=-0.101, p<0.01) and relative humidity (R=-0.053, p<0.05). The rainfall had a positive correlation with the numbers of Tx. splendens larvae (R=0.087, p<0.01) and Ae. albopictus larvae (R=0.074, p<0.01). The numbers of Ae. albopictus larvae was negatively correlated with temperature (R=-0.047, p<0.05) and positively correlated with relative humidity (R=0.121, p<0.01). There was a significant different between the numbers of Tx. splendens larvae occurred in two locations (p<0.05) and in different types of container (p<0.05). We concluded that Tx. splendens can be utilized as a potential biological control agent to reduce the population of Ae. albopictus.