Failure of The asian tiger mosquito, Aedes albopictus to Overwinter Following Introduction and Seasonal Establishment at a Tire Recycling Plant in connecticut

Theodore G. Andreadis

The Connecticut Agricultural Experiment Station

123 Huntington Street, P.O. Box 1106

New Haven, CT 06504

theodore.andreadis@po.state.ct.us

ABSTRACT

The Asian tiger mosquito, Aedes albopictus is presently recognized as the most invasive mosquito in the world having spread from its native range in Southeast Asia to at least 36 countries over the last three decades. This has occurred primarily through the worldwide trade in used tires and more recently via containerized shipments of infested ornamental “lucky bamboo” plants. In the United States, established populations of this species have been reported from 866 counties in 26 states in the eastern half of the country extending from southern Florida and Texas, to Chicago, Illinois the northernmost infestation. In the northeast, Ae. albopictus has invaded much of New Jersey, portions of southern Pennsylvania, and the New York City metropolitan area. However, while a few individuals have been occasionally collected in surveillance activities in the neighboring New England states, no established infestations have been identified in this region.

In July 2006, an introduction of the Ae. albopictus was documented for the first time at a commercial tire recycling plant in northeastern Connecticut. The introduction likely occurred via transport of infested tires originating from northern New Jersey or metropolitan NYC. Upon this discovery, field and laboratory investigations were initiated to determine seasonal establishment and overwintering success by assessing adult biting and oviposition activity in the surrounding woodlands. The first adult female was collected in a CO2-baited Mosquito Magnet® Liberty trap within the confines of the tire plant during the week of July 28. Additional females were collected intermittently thereafter through October 16. Host-seeking female Ae. albopictus attempting to alight on human subjects and larvae hatching from eggs collected in ovitraps placed in the woodlands surrounding the tire plant, were detected weekly from August 21 through October 2 denoting seasonal establishment in the immediate woodlands. However, no larvae of Ae. albopictus were recovered from eggs collected in ovitraps that were placed in the surrounding woodlands or in traps placed 1 to 1.6 km away, nor were any host seeking females detected by human subjects the following season (July to October 2007), indicating that the species did not survive winter conditions to enable successful colonization. The failure of Ae. albopictus to overwinter and establish itself in the forested woodlands following several weeks of seasonal breeding and oviposition during the summer and early fall were most likely due to winter egg mortality, interspecific competition from Ochlerotatus triseriatus and Ochlerotatus japonicus and/or other ecological barriers. This study indicates that permanent establishment of this invasive mosquito in New England is unlikely despite the recurring importation of infested used tires into recycling facilities. However, continued monitoring of such facilities for potential re-invasion is warranted especially in urban/suburban environs where global warming and milder winter temperatures may provide more suitable conditions in the future for colonization.