(July 1, 2005) -- Mounting an attack on adult mosquitoes (not just water treatments to suppress pre-mosquito larvae) in an area where West Nile infected mosquitoes were recently found, the Greater L.A. County Vector Control District (GLACVCD) has done three pre-dawn ground foggings in the oil sump/unrestored wetlands area of the Bixby Oil Field and the nearby Long Beach Marketplace.

Between 2 a.m. and 5 a.m. on three alternating days in late June, GLACVCD spread what it calls an ultra low volume of ground based synthetic pyrethroid, similar to pyrethrum derived naturally from chrysanthemum flowers, which has the immediate impact of reducing the number of adult mosquitoes and then dissipates quickly.

LBReport.com only learned about the procedures (which are now concluded) after a news tipster spotted a small sign in the area and let us know.

We stopped by on June 30 and found this small sign, placed at lower leg level on the south side of 2d St. east of PCH. We reproduce the text below:

GLACVCD staffers say their data indicate that the ground foggings are estimated to have reduced then-present adult mosquitoes by 85-90% (and possibly more).

In 2004, GLACVCD (which handles areas of LB north of PCH and east of Lakewood Blvd.) used ground fogging (called "adulticiding" because it kills adult mosquitoes) along the Rio Hondo and San Gabriel River corridors and at Macado Lake in Ken Malloy Harbor Regional Park where West Nile infected mosquitoes were found.

As described at that time in a written release, District Manager Jack Hazelrigg said the "small amount of active ingredient...is in the form of microscopic droplets, and literally only molecules of the killing agent are used to kill mosquitoes, which essentially negates exposure and risk to people and the environment." The release said it is "one of the least poisonous insecticides to mammals and low in toxicity because it is quickly broken down into inactive forms."

Minoo Madon, GLACVCD's Scientific-Technical Services Director told LBReport.com that small amounts of the synthetic pyrethroid are dispersed using droplets of mineral oil, killing the mosquitoes and then quickly dissipating.

He indicated that ground fogging requires specific weather conditions including calm winds and a helpful temperature inversion...and those conditions were present for the recent pre-dawn procedures.

West Nile virus spreads when mosquitoes bite birds infected with the virus (through a previous bite from an infected mosquito) and then bite people. Authorities say most people bitten by a West Nile infected mosquito show few symptoms or no symptoms, but for reasons still not completely understood about 1 in 10 or 15 may develop serious, potentially life threatening neurological conditions such as encephalitis and meningitis.

Last year, an elderly ELB woman (area Clark/Wardlow) died and 15 other LB residents were confirmed to have contracted the virus.

"Symptoms of WNV infection typically begin between 7 to 14 days following the bite of an infected mosquito, and consist of fever, muscle and joint aches, fatigue, headache, and other flu-like symptoms. Elderly and immune suppressed individuals are at much greater risk for developing serious WNV illness such as encephalitis (inflammation of the brain)," LB's Health Dept. says in a written release.

On June 15, LBReport.com reported that Long Beach and Cerritos had their first confirmed 2005 instances of West Nile virus mosquitoes. GLACVCD said WNV positive mosquitoes were collected on June 7 and June 10 in the vicinity of the MarketPlace at 2d St./PCH and in the Marina Pacifica areas. (LB's Dept. of Health of Human Services (which handles most of the rest of LB, except the NW corner handled by Compton) said West Nile positive mosquitoes were also collected at about the same time in the "California Bowl" area near Signal Hill).

"[GLACVCD] will continue maximum efforts in controlling mosquitoes in the vicinity," the agency said in a written release at the time. "Positive mosquitoes from these locations within the District strongly indicates that West Nile virus activity is rapidly increasing," said Mr. Madon in the agency's release at the time.

On May 27, 2005, LBReport.com reported LB's first WNV infected dead crow in ELB zip code 90815. Nelson Kerr of LB's Dept. of Health and Human Services Vector Control division tells LBReport.com that four other WNV-positive dead crows have since been found in areas including zip codes 90815, 90803 and 90808.

The LB Health Dept. says in a written release: