Officials in Berks County continue to set their sights on mosquitoes that may be carrying the West Nile virus.

The Berks County West Nile Program will conduct an ultra-low volume spray operation in parts of Cumru Township and Shillington on Thursday, officials announced Tuesday.

Weather-permitting, a specially-equipped truck will spray Biomist 3+15 ULV at a rate of 0.75 ounces per acre, said officials, adding that the product is designed to provide quick, effective control of adult mosquito populations.

If the weather is unfavorable for spraying Thursday, it will be pushed back to Friday.

Mosquito spraying is also scheduled for parts of Exeter Township on Wednesday, officials said.

The operation's goal, officials said, is to reduce high populations of mosquitoes that can transmit the West Nile virus.

Five out of nearly 200 mosquitoes that have been tested for West Nile virus in Berks County so far this summer have come back positive, said officials with the Pennsylvania Department of Environmental Protection.

The West Nile-carrying mosquitoes have been found in Cumru Township on July 10 and July 17; Washington Township on July 11; Exeter Township on July 16; and Bally on July 19.

According to the DEP, individuals can take a number of precautions around their homes to help eliminate mosquito-breeding areas, including:

• Dispose of cans, buckets, plastic containers, ceramic pots or similar containers that hold water.

• Properly dispose of discarded tires that can collect water. Stagnant water is where most mosquitoes breed.

• Drill holes in the bottom of outdoor recycling containers.

• Have clogged roof gutters cleaned every year as the leaves from surrounding trees have a tendency to plug drains.

• Turn over plastic wading pools when not in use.

• Turn over wheelbarrows and don't let water stagnate in birdbaths.

• Aerate ornamental pools or stock them with fish.

• Clean and chlorinate swimming pools not in use and remove any water that may collect on pool covers. If a resident has stagnant pools of water on their property, they can buy BTI products at lawn and garden, outdoor supply, home improvement and other stores. This naturally occurring bacterium kills mosquito larvae, but is safe for people, pets, aquatic life and plants.