Testing, traps to reduce Depot's insect population

30 Apr 2004 | Lance Cpl. Brian Kester Marine Corps Training and Education Command

Spring is here and with it comes warmer weather, fun in the sun and, on Parris Island, the familiar smell of bug spray.

That is why the Branch Medical Clinic's Preventative Medicine Department, Depot Natural Resources and Depot Pest Control team up every year to deter the pests from ruining the outdoor fun of Depot personnel and residents.

During April, this team of pest fighters began monitoring the mosquitoes for West Nile Virus and for population counts, which determines where pest control will spray.

They begin by setting traps that lure the mosquitoes in, so they can be tested and counted. Each trap has an attractant to lure them in, such as stagnant water, an enticing breeding ground or a simple light, which attracts bugs of all types. Then a fan pulls the insects into the trap where their fate is sealed.

"Female mosquitoes breed by laying their eggs near water that has organic material in it," said Petty Officer 2nd Class Timothy Worley, Preventative Medicine technician. "We set up the trap so it has the kind of water they are looking for to lay their eggs. The eggs then hatch into larvae which live in that water."

The female of the species are specifically targeted by Preventative Medicine because they bite, which can lead to the transmission of diseases.

"Female mosquitoes are the only ones that bite people or animals," said Worley. "The reason behind the bite is they are looking for a blood meal they use as a source of nutrition to feed their young."

The important thing is those mosquitoes are collected and then sent off to get analyzed.

"Mosquitoes are very problematic when it comes to diseases," said Worley. "They carry Malaria and West Nile, two different types of viruses we are concerned with. The best way for us to control the spread of those diseases is to control the mosquito population."

In order to monitor the populations of these insects, there are several types of traps used to count populations and test for disease.

"We have three different types of traps that are put out during the season," said Worley. "We monitor for a certain level of mosquitoes. If we detect a certain level of mosquitoes in an area, then Depot Pest Control will go out and spray in that area. We need to keep that population down, because the higher the population of mosquitoes, the more people are bitten and the more likely that diseases are going to be transmitted."

To curb the transmission of diseases, the area population is under observance and controlled by Natural Resources.

The mosquito populations have been monitored for more than 30 years, said Jim Clark, environmental coordinator for Natural Resources.

"We monitor for mosquito larvae and we spray for mosquitoes when the counts go up in certain areas," added Clark.

When a population is detected as being at a high level, the numbers are given to Depot Pest Control.

"Normally when we check for mosquitoes and we get a certain count in an area, we have to fog," said Neil Thornal, facilities pest controller. "So we'll fog until the counts go down. Last year we fogged 80 percent of the time because the counts were high all year long."

Even though fogging can control the numbers, it is not a permanent solution to the problem.

"It is important for people to understand no matter how much we spray and try to control the mosquitoes, we will never be able to control the entire population," said Worley. "If you are going to be out side you need to spray on a personal protectant or maybe keep your sleeves down at night. We are doing our very best to control them, but we live in an area where there is a lot of standing water, and you are going to have mosquitoes."

While the mosquitoes are number one on the watch list, there are other signs of the West Nile Virus.

"We are also looking out for dead bird activity," said Clark. "Corvids, Black Birds, Grackles and Crows are highly susceptible to West Nile. They act like a sentry for us, to let us know the disease is in the area."

Even though there has never been any confirmed case in this area, that is not to say that it cannot happen. Both Preventative Medicine and Natural Resources urge people to take the proper precautions.

"The Centers for Disease Control, www.cdc.gov, has a West Nile Virus homepage that has some great tips for people," said Clarke. "It talks about insect activities, the times of day they are active and the need for wearing repellents. Keep an eye out for things that can collect and retain water, those kinds of things should be emptied on a regular basis."

In addition to fogging and personal precautions, other larger scale precautions have been taken by Natural Resources.

"An Air Force C-130 comes in and does our aerial spray for us a couple of times a year in the spring and the fall," said Clark. "They are due to come on the 7th and the 10th of May."

Marine Corps Training and Education Command