Each year around Willapa Bay beginning in May or earlier come the hordes of mosquitos whose sole regenerative purpose are met in part by feeding on hapless exposed humans who wander into their territory. Their preferred habitat can be as close as right outside your back door. They are tenacious and relentless in the pursuit to fully carry out their life cycle. They can without hesitation even bite through a t-shirt in the quest for nourishing blood. Some species in particular rush straight in to immediately begin delivering a painful itchy bite. A convincing example of aggressive mosquito behavior.
Mosquito biology is generally pretty straightforward. They are members of the true fly family, order Diptera. They undergo four separate and different stages during their life cycle. It begins in the following order with the egg, larva, pupa and adult stages. The minute eggs are sticky and are layed in groupings on the surfaces of any quiet fresh water sources in masses of hundred or more eggs. The eggs take on the appearance of a tiny raft. Larva soon hatch and begin to actively feed on micro-organisms. They will molt four separate times as they increase in size before eventually becoming pupas. The pupa stage is a non-feeding resting stage whereas the adult mosquito emerges in a couple of days. The females hunt for blood begins. This whole cycle can take as little as two weeks to complete. Very efficient. Only the female mosquito possess the specialized mouth structure called a proboscis designed to pierce the skin of a warm blooded mammal. She feeds on blood for life giving proteins. The males have a totally different mouth structure which enables them to only feed on flower pollen for nutrition.
There are approximately 2,500 different species of mosquitos existing worldwide, of which 150 are found in the United States. Mosquitos can carry diseases such as the malaria parasite and West Nile virus. Any mosquito species determined to carry such diseases are classified as a vector species. There are 58 known mosquito vector species in the U.S. which are identified as potential carriers of West Nile virus, while only 19 out of these 58 have been identified in Washington state alone. This does not mean West Nile virus is present at this time or that all of Washington's 19 known mosquito vector species are found in Pacific County. However, there could be some vector mosquito species present that are capable of transmitting the virus. To date the virus has not yet been determined to be present in any of our mosquito species known to reside in our area.
Monitoring of mosquito species is an important tool currently being implemented right here throughout Pacific County in the determination and testing for West Nile virus by the Washington State Department of Health-Office of Environmental Health and Safety. Mosquito traps are being currently set out in different locations of suitable mosquito habitat around Willapa Bay under the supervision of wildlife biologist Marie Fernandez of the Willapa National Wildlife Refuge. Friends of Willapa National Wildlife Refuge members, John Schroeder and Russ Lewis are volunteers who trap the mosquitos for Marie who in turn coordinates the results with personnel from Washington State Department of Health. Mosquitos are trapped once every two weeks. The trap consists of a dry ice filled canister with a net trap attached to the underside of the canister. It is attached to a tree limb about six feet above the ground and kept in operation overnight. There is a small electric fan located between the canister and net trap that blows carbon dioxide downward from the canisters dissipating dry ice. The carbon dioxide filters through the net trap. Mosquitos are attracted by carbon dioxide and enter the net trap. It's a one-way trip. They are collected and eventually sent off for species identification and for the presence of the virus. Of interest is the fact that over 600 mosquitos were trapped in one night in June at Leadbetter Point, while by mid-August only 23 were trapped at the same location. Numbers seem to generally peak in early summer. June is obviously not the time to plan a picnic at Leadbetter Point as beautiful and enticing as that place is.
For more information on West Nile virus contact The Department of Health West Nile virus Web site http://www.dohwa.gov/WNV and toll free information line (1-866-78VIRUS) which will have the latest information on bird, horse and human cases in the state. Information on mosquito biology can be found on website (http://www.mosquito.org/mosquito.htm). To learn more or join Friends of Willapa National Wildlife Refuge, visit (www.willapabay.org/~fwnwr) or contact Bev Arnoldy at (email@example.com) or call 360-665-0115.