Asian tiger mosquito

Staff from the San Gabriel Valley Mosquito and Vector Control District conducting routine surveillance have detected immature (larval) Asian tiger mosquitoes (Aedes albopictus) in the City of Arcadia. Their identity was confirmed when the larvae emerged as adults. The mosquitoes were found approximately ¼ mile northeast of the intersection of Live Oak and Santa Anita Avenues near the City of Arcadia’s southern border.

This is the first time Asian tiger mosquitoes have been found in the city of Arcadia and represents the current northern-most reach of the infestation. Last fall, tiger mosquitoes were identified on several properties in unincorporated Los Angeles County just south of the city of Duarte, but no activity has been detected from that area this year.

This year, the Asian tiger mosquito has been detected on approximately 240 properties in the cities of El Monte and South El Monte. This sample was collected nearly 2 miles north of the current infestation. Asian tiger mosquitoes are weak flyers and rarely travel more than 200 meters from where they were born. They prefer yards with numerous sources of standing water, lush and/or overgrown vegetation, and areas that provide cool, humid microclimates. They can lay eggs and complete their life cycle in as little as 1 tablespoon of water, and their eggs can lay dormant for 1-2 years. People may unwittingly transport larvae or eggs when they move or share plants and plant clippings that have been rooted in water. Adult mosquitoes can be transported unknowingly in vehicles.

The Asian tiger mosquito is an aggressive day-biting mosquito. Since last fall, the District has received numerous reports of children covered in mosquito bites, and people unable to spend time in their own backyards. This mosquito is highly adapted to surviving in urban environments and is difficult, if not impossible to remove from an area once it becomes established without aggressive actions. While there is no indication that they are currently transmitting any pathogens, they are widely regarded as being one of the best vectors (transmitters) of important human pathogens, like dengue virus.

The San Gabriel Valley Mosquito & Vector Control District urges residents to cooperate fully with District staff:

1. Allow prompt access for inspections and treatments

2. Permanently remove all containers that hold water from your yard – especially saucers/dishes under potted plants, buckets, cans, used tires, and debris around the yard

3. Drill holes in tire swings, trash cans, or any other necessary outdoor containers so that water will drain

4. Keep ponds and fountains circulating and functioning to eliminate mosquitoes – request free mosquito-eating fish from the District

5. Store recyclable goods in sealed cans or bags inside a garage or covered carport

6. Search under bushes and in hidden areas for trash, plastic tarps, or other items that may collect rain or sprinkler water and discard them

7. Clean rain gutters and yard drains of leaves, grass clippings, and debris so water will flow freely

8. Report tiny, black and white, day-biting mosquitoes

Residents who suspect tiger mosquitoes on their property should immediately survey their yards and dump out all standing water and contact the District at 626.814.9466 or online at sgvmosquito.org. The San Gabriel Valley Mosquito & Vector Control District is a public health agency dedicated to the control of mosquito- and other vector-borne diseases.