La Crosse virus spread within the mosquito population in Knox County, TN.

In Appalachia, La Crosse virus (LACV) is a leading pediatric arbovirus and public health concern for children under 16 years. LACV is transmitted via the bite of an infected Aedes mosquito. Thus, it is imperative to understand the dynamics of the local vector population in order to assess risk and transmission. Using entomological data collected from Knox County, Tennessee in 2013, we formulate an environmentally-driven system of ordinary differential equations to model mosquito population dynamics over a single season. Further, we include infected compartments to represent LACV transmission within the mosquito population. Findings suggest that the model, with dependence on degree days and accumulated precipitation, can closely describe field data. This model confirms the need to include these environmental variables when planning control strategies.

Comparison of Trap Collections and Cost of Commercially Available and Homemade Yellowjacket (Hymenoptera: Vespidae) Traps in Lake County, California.

Yellowjackets are notable pests of humans due to their opportunistic foraging behaviors, painful stings, and potential for causing dangerous allergic reactions. Baited traps provide a useful supplement for controlling yellowjackets compared with nest treatments, which are often dangerous, time consuming, costly, and do little to prevent nuisance interactions between humans and foragers. This study compares three homemade yellowjacket traps and three commercially available traps in Lake County, California, to determine efficacy and cost benefit. Traps were set at five sites and randomly rotated between six plots per site and baits were changed every 2 wk per commercial manufacturer recommendations. Cost benefit was determined using material and bait cost, as well as bait change frequency and overall trap efficacy. Yellowjacket count data were analyzed using a hurdle model. Traps compared included the Rescue! Yellowjacket trap, the Rescue! Wasp, Hornet, and Yellowjacket trap, the Victor Yellowjacket trap, a homemade bottle trap, jar trap, and homemade jug trap. The total number of yellowjackets collected was 33,321. The trap that collected the highest number of yellowjackets was the Rescue! Yellowjacket trap (n = 19,257) and the trap that collected the fewest yellowjackets was the jar trap (n = 65). The Rescue! Yellowjacket trap was the most cost-effective, calculated at approximately $0.40/100 yellowjackets collected. The jar trap was the least cost-effective, calculated at approximately $31.10/100 yellowjackets collected. The Rescue! Yellowjacket trap was overall the most effective and cost-effective trap evaluated for Lake County, California.