Developmental stage and level of submersion in water impact the viability of lone star and winter tick eggs during flooding

Abstract

Female ticks deposit large egg clusters that range in size from hundreds to thousands eggs each. These clusters are immobile and restricted to a deposition site, usually under leaf litter and other debris. These sites can be exposed to periodic flooding, where the cluster of tick eggs can float to the surface or remain underneath organic debris entirely submerged underwater. Here, we examined the viability of egg clusters from winter ticks, Dermacentor albipictus, and lone star ticks, Amblyomma americanum, when partially or fully submerged in water and in relation to the developmental stages of the eggs. In general, egg clusters that were older and partially submerged had a higher viability than fully submerged, younger eggs. A. americanum was more resistant to water exposure between the two species. These studies highlight that egg clusters for certain tick species can remain viable when exposed to water for at least two weeks. These studies also suggest that distribution by flooding of egg clusters could occur for some species and flooding will differentially impact tick egg survival based on the specific developmental stage of exposure and species.