Our surveillance program consists of 2 full time surveillance inspectors, and an Entomologist. Surveillance is performed 5 days a week beginning at 5:30 am. During mosquito season inspectors perform landing rate counts, larva counts, and examine salt marshes. If excessive larva counts are found then larvicide is set out. They also conduct routine trapping for West Nile testing. If complaint calls are received then surveillance inspectors are sent out to investigate the area of concern. The inspectors are an important part of our mosquito control district. The data collected is used to determine what control methods are needed.
Landing Rate Counts
Landing rate counts are conducted to measure adult mosquito activity in a specific location or area. This is achieved by counting the number of mosquitoes that land on a person within 1 minute. These counts are preformed daily by our surveillance inspectors. We have several landing rate locations located throughout the county so that the inspectors maintain a consistency. By looking at the landing rate counts we can determine if an area needs to be sprayed or if an isolated area needs to be sprayed.
Larval Sampling
Larva sampling is an important part of our daily operations. Our inspectors survey areas that contain water and inspect for the presence of larva. After collecting larva samples we can determine what kind of mosquito we are concerned with and how far long they are in their cycle. If inspectors find excessive amounts of larva then larviciding is performed. By evaluating the amount of larva present and their stage of their larva cycle then we can predict when they will hatch and estimate how large of a population we can expect. This allows us to prepare to treat for large amounts of adults if necessary. Our marshes are also monitored routinely for tidal flooding. We monitor environmental changes, such as rainfall and tide levels. Knowledge of environmental conditions helps us to anticipate changes in mosquito populations. We can then determine if we should expect a hatch off from salt marshes.
Traps and Testing
Galveston County Mosquito Control uses two different types of traps, CDC and Gravid. Traps are set up 1-2 times a week at designated locations throughout the county. The traps are collected the next day and the mosquito samples are sent off to the Texas Department of Health for testing. They then determine if any mosquito-borne viruses are present and report their finding back to us. One of our main focuses is monitoring for any West Nile outbreaks. If a mosquito sample comes back positive then more traps are placed around the location. Inspectors will continue to monitor the location for any more positive mosquito samples.
Sentinel Flock
In our continuation of monitoring for West Nile and other mosquito borne diseases we have created a sentinel flock program. Sentinel flocks can be used to test for mosquito borne viruses. For our sentinel flocks we use chickens. We place chickens in 5 different locations within the county. Each location has a total of 5 chickens. We select homeowners who already have chickens of their own and ask permission to place our chickens in their care. The chickens are bled once a month. The blood is collected and sent off to UTMB for testing. The lab tests for the West Nile virus, St Louis encephalitis, and Easter Equine Encephalitis.
Service Requests
The county has a phone line available for residents to call to request spray services or report possible breeding sites. A request does not mean we will automatically spray your area. We use this data along with our surveillance inspections to make our daily spray schedules. Our inspectors can’t be everywhere at once and there are often times when a request notifies us to a problem area or breeding site. Some service requests also refer to problems that a homeowner is causing themselves. As part of our continuing public education we may inspect the homeowner’s property and point out any potential breeding sites they are causing. It is important to remember to empty out all water holding containers. These include: bird baths, pots, wheel barrows, tires, or any open containers.
