June 17, 2000

Because of the hotter weather being experienced locally and the late rains from last month, Turlock residents are expected to have a real problem with mosquitoes this summer.

According to Jerry Davis, manager of the Turlock Mosquito Abatement District (TMAD), "Statistically, we're showing about three times as many mosquitoes in the Turlock area as there were at this time last year."

According to TMAD data, weather during this last month was warmer than normal and rainfall was well above normal. Average daytime highs and nighttime lows for the month was two degrees above normal for the five-year average.

From observing trap summary indexes used by TMAD, abatement workers have been noticing a significant increase in both adult mosquitoes and their larva. Davis directly credits the warmer weather and late rains as the main reason for the increase locally.

"The late rains have filled all sorts of containers with standing water and provided an ideal location for mosquitoes to breed. With the warmer weather, these containers are providing perfect conditions for breeding," he said.

Davis also credits late irrigation as another factor contributing to the increase.

Some of the most locations where mosquitoes breed include containers of various sorts such as buckets, cesspools or septic tanks, ponds, irrigated lawns and fields, bird baths, house-cooler drains, open ditches in residential areas, tree holes, swimming or wading pools, water under homes or in basements and roof gutters.

The reason these places become such suitable sources for mosquito breeding has to do with their reproductive requirements.

According to TMAD literature, water is a necessity for three of the mosquitoes four life stages.

After the female mosquito lays her eggs on a source of standing water, the eggs are able to hatch. Once hatched, the eggs become a larvae which later transforms into pupae, from there, the adult mosquitoes will emerge and fly away.

While the male mosquito only lives a few days and does not bite, the female will live for about a month or more and will seek out sources of blood including humans, pets and livestock.

Davis points out that testing is also done to see if local mosquitoes are carrying any forms of disease. The tests are performed at the University of California, Davis Center for Vector-Borne Disease Research.

"So far, the tests have been negative of any virus this year," Davis said.

While most of the Central and Northern portions of the San Joaquin Valley is looking at an increase, Bill Risen, who manages the Mosquito Abatement District for the Bakersfield area, said, "The sourthern portion of the San Joaquin Valley will probably be experiencing similar mosquito populations as the last couple of years. There may even be lower numbers in some areas like the Cochia Valley where they experienced less rain this year."

Roselyn Cunningham, a registered nurse in the communicable disease program for Stanislaus County Public Health recommends that people, "try to keep your arms covered or use a mosquito repellent to avoid being bit, especially at dusk when they are biting the most. Prevention is the best means of avoiding health problems associated with mosquitoes."

Davis advises Turlock residents that if they are experiencing a problem with mosquitoes, call the abatement district at 634-1234.

Reprinted by permission of The Turlock Journal.