Regulatory factors affecting larval mosquito populations in container and pool habitats: implications for biological control

Abstract

Empirical studies have shown that populations of larval mosquitoes developing in ground pools are subjected to different mortality factors than populations developing in water-filled containers. In general, larvae in ground pools are limited by natural enemies whereas those in containers are limited by resource availability. Containers also are typically smaller than ground pools and lack appreciable internal primary productivity. These physical and biological features have significant implications for successful implementation of biological control agents. Island biogeography theory suggests that container habitats will support smaller populations of fewer species compared to ground pools, implying that it may be more difficult to establish natural enemies in container habitats. The lack of primary productivity within containers may limit the number of trophic levels and reduce the likelihood of establishing and maintaining predator populations. Most importantly, larval mosquito populations in containers are regulated by competitive interactions, and mortality from natural enemies is likely to be compensatory. These habitat and population characteristics, combined with difficulties in locating and treating containers, suggest that successful control of ground pool mosquitoes using biological control agents is more feasible.