Assessing the Utility of Mosquito Surveillance Bycatch for Tick Population Monitoring

Amblyomma americanum (lone star tick) and Dermacentor variabilis (American dog tick) are known to be vectors of zoonotic pathogens, such as Ehrlichia chaffeensis and Rickettsia rickettsii, respectively. It is crucial to public health safety to understand the population trends of these ticks. Flagging is a common method for active tick surveillance, yet for some ticks, other methods such as CO2 traps can yield similar results. Some mosquito species are collected with traps that use CO2 and can attract ticks as bycatch. We compared numbers of ticks collected per year from 2012 to 2024 by Suffolk County Mosquito Control using mosquito traps to numbers of flagged ticks collected from the ODU Tick Team in the same area. Using R, we fitted a negative binomial generalized linear model to determine if the two methods were equivalent. We found the two collection methods were significantly different with respect to the number of adult lone star ticks (p-value < 0.001). There was no significant difference for adult dog tick populations (p-value = 0.300), but there were very few American dog ticks collected. This analysis provides that incidental mosquito bycatch does not reflect lone star tick trends. Further work is needed before bycatch is used as a method to measure tick population trends.