Comparison of Trap and Equine Attraction to Mosquitoes

SIMPLE SUMMARY: Mosquitoes are pests of horses. We evaluated the ability of traps to protect horses from these blood feeders. To evaluate comparative attraction, a horse was placed 3.5 m from a mosquito trap. Fewer mosquitoes were trapped because mosquitoes were more attracted to the horse. Trapped mosquitoes increased after removing the horse from the area. Increasing trap attraction by adding horse odors into the trap airstream was unsuccessful because the horse supplying the odors could not be moved far enough away. Three mosquito traps spaced at the study site showed that mosquitoes were not evenly distributed and fewer were collected near structures. This shows the importance of trap placement. When horses were vacuumed, 324 and 359 mosquitoes/h were found feeding on the animals during summer and fall studies, respectively. A nearby mosquito trap simultaneously captured 224 mosquitoes/h. The numbers of mosquitoes vacuumed simultaneously from two horses showed that one horse attracted twice as many mosquitoes as the other. All horses are not equally attractive to mosquitoes. For better mosquito management with traps, the attractive range of traps and host animals must be known. Traps must be as attractive to mosquitoes as host animals so traps can better protect host animals. ABSTRACT: Mosquitoes are pests of horses, but mosquito trap efficacy data, especially the ability of traps to protect horses, are lacking. Studies were conducted to investigate the comparative attraction between traps and horses, increase trap attraction by adding horse odors to the airstream of a trap, determine the spatial distribution of adult mosquitoes, estimate the numbers of mosquitoes feeding on horses, determine the relative attraction of horses to mosquitoes, and estimate the range of mosquitoes’ attraction between two horses. When a horse and a mosquito trap were placed 3.5 m apart, there was a significant reduction in mosquitoes entering the trap. Adding horse odors to the airstream of a trap produced equivocal results because the horse providing the odors influenced the trap catches. Mosquitoes were not evenly distributed across the study site, which emphasized the importance of trap placement. Vacuuming mosquitoes from the horses in different seasons demonstrated that 324 and 359 mosquitoes per hour were feeding during the two studies. Separate analysis of data from the two horses vacuumed simultaneously revealed that one horse attracted twice as many mosquitoes as the other. This caused the results of a study to determine the attraction range of two horses moved from 3.5 to 20.4 m apart to be inconclusive.