Week 3 - Sam Meyer

Hello everyone, these last couple weeks have kept us busy in Delta. I have learned more and more about mosquito's every week! More specifically, I have learned how to correctly identify the mosquitos that we capture. This took some practice at first but it became surprisingly easy over time. Here in Delta County, we are primarily searching for Culex tarsalis due to their ability to spread West Nile Virus. Luckily, these Culex tarsalis have a very prominent white band on their proboscis that makes them very easy to identify. Although we have had some pools of Tarsalis we have not had any positive for West Nile. 

This was a cool photo of a Culex Tarsalis we took here in Delta County.

Additionally, once a week I have been able to go out with the mosquito control district to see everything they do to control the local mosquito population. I have been able to see how BTI (Bacillus Thuringiensis Istaelensis) is being used to eliminate larva in standing water. This BTI comes in forms of granules that are either spread over large areas of water or briquettes that can be used to regulate the release of BTI in a specific area over a longer period of time. It has been interesting to learn how BTI is able to target mosquito larva and has almost no negative affects to the surrounding environment. Although 80% of mosquito prevention happens in the larva stage, BVA oil is one of the only ways to prevent mosquitos in the pupa stage. Since pupa do not eat, the BTI is no longer effective. This is where BVA oil is necessary, BVA oil is a highly refined mineral oil that increases the surface tension of water. Therefore, when the BVA oil is sprayed on to pupa filled water, the pupa are no longer able to penetrate the surface to breath which will drown them. I was also surprised to see the lengths that the mosquito control district goes to assess all water in Delta County. When I was with the mosquito control district we where hiking through thick grass and bushes to get to ponds. When we arrived we used a method called dipping to check for mosquito larva. If we found mosquito larva we treated the area with BTI and if not we moved on. I was very impressed to see all of the work that they do to check for mosquito larva and ensure that the BTI was working properly.