The hidden world of Asian tiger mosquitoes: immature Aedes albopictus (Skuse) dominate in rainwater corrugated extension spouts.

BACKGROUND The primary sources of Aedes albopictus (Skuse) in its exotic range in North America are artificial containers in backyards, which vary widely in accessibility. In this study we examined their prevalence in two container types that are difficult to inspect: catch basins and corrugated extension spouts (CES), the latter used to divert rainwater in downspouts away from house foundations. METHODS We conducted larval and pupal surveys in catch basins, CES and open containers such as buckets and plant saucers in three urban locations in Mercer County, New Jersey, USA. RESULTS We found that Ae. albopictus were rare in catch basins but prevalent in CES, and were often the only species collected in CES. Specific characteristics of the CES were not significantly associated with the presence or number of Ae. albopictus in them, but those longer and closer to the ground were significantly more likely to contain water, and therefore mosquitoes. During peak season (July-August), the abundance of immature Ae. albopictus was significantly higher in CES than open containers. CONCLUSIONS We found that CES are an important source of Ae. albopictus in our region and propose that effective control strategies should be implemented to minimize mosquito populations from these cryptic habitats.