Effects of sublethal permethrin exposure on larval Culex pipiens response to conspecific alarm cues

Organisms living in aquatic environments rely on olfactory, or chemical, information to assess predation risk in environments that are often turbid and difficult to navigate. Utilizing olfactory signals and cues enables aquatic prey to assess predation risk and grade antipredator responses to match the perceived degree of risk, which can improve survivability and fitness. Today, many aquatic habitats can become contaminated with lethal or sublethal concentrations of pollutants and pesticides which, in turn, could influence predator-prey dynamics. The purpose of this study was to examine the behavioral response of larval Culex pipiens to a simulated predation event by introducing conspecific alarm cues following exposure to sublethal concentrations of the insecticide permethrin. Larval responses were analyzed for three common antipredator behaviors comprised of distance traveled, mean velocity, and change in mobility. While permethrin exposure resulted in no significant change in behavioral response, significant differences were noted in response to the presence of aqueous extracts from crushed conspecific larvae. Although permethrin exposed larvae did not exhibit statistically significant differences in response to alarm pheromone, a trend showing incrementally smaller intensities in behavioral responses could be seen with increasing concentrations of alarm cue. This research demonstrates that even low concentrations of permethrin exposure can influence larval Culex pipiens behavioral response to conspecific alarm cues which could have meaningful implications for larvae existing in predator rich environments contaminated with pesticide

Impacts of deciduous leaf litter and snow presence on nymphal Ixodes scapularis overwintering survival in coastal New England.

Blacklegged ticks (Ixodes scapularis Say) are the vector for pathogens that cause more cases of human disease than any other arthropod. Lyme disease is the most common, caused by the bacterial spirochete Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner) in the northeastern United States. Further knowledge of seasonal effects on survival is important for management and modeling of both blacklegged ticks and tick-borne diseases. The focus of our study was on the impact of environmental factors on overwintering success of nymphal blacklegged ticks. In a three-year field study conducted in Connecticut and Maine, we determined that ground-level conditions play an important role in unfed nymphal overwintering survival. Ticks in plots where leaf litter and snow accumulation were unmanipulated had significantly greater survival compared to those where leaf litter was removed (p = 0.045) and where both leaf litter and snow were removed (p = 0.008). Additionally, we determined that the key overwintering predictors for nymphal blacklegged tick survival were the mean and mean minimum temperatures within a year. The findings of this research can be utilized in both small- and large-scale management of blacklegged ticks to potentially reduce the risk and occurrence of tick-borne diseases

Impacts of Deciduous Leaf Litter and Snow Presence on Nymphal Ixodes scapularis (Acari: Ixodidae) Overwintering Survival in Coastal New England, USA

Blacklegged ticks (Ixodes scapularis Say) are the vector for pathogens that cause more cases of human disease than any other arthropod. Lyme disease is the most common, caused by the bacterial spirochete Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner) in the northeastern United States. Further knowledge of seasonal effects on survival is important for management and modeling of both blacklegged ticks and tick-borne diseases. The focus of our study was on the impact of environmental factors on overwintering success of nymphal blacklegged ticks. In a three-year field study conducted in Connecticut and Maine, we determined that ground-level conditions play an important role in unfed nymphal overwintering survival. Ticks in plots where leaf litter and snow accumulation were unmanipulated had significantly greater survival compared to those where leaf litter was removed (p = 0.045) and where both leaf litter and snow were removed (p = 0.008). Additionally, we determined that the key overwintering predictors for nymphal blacklegged tick survival were the mean and mean minimum temperatures within a year. The findings of this research can be utilized in both small- and large-scale management of blacklegged ticks to potentially reduce the risk and occurrence of tick-borne diseases

Determining Effects of Winter Weather Conditions on Adult Amblyomma americanum (Acari: Ixodidae) Survival in Connecticut and Maine, USA

The lone star tick

Prevalence and genetic characterization of deer tick virus (Powassan virus, lineage II) in Ixodes scapularis ticks collected in Maine.

Deer tick virus (DTV) is a genetic variant of Powassan virus (POWV) that circulates in North America in an enzootic cycle involving the blacklegged or deer tick

Fatal deer tick virus infection in Maine.

Deer tick virus (DTV), a genetic variant (lineage II) of Powassan virus, is a rare cause of encephalitis in North America. We report a fatal case of DTV encephalitis following a documented bite from an Ixodes scapularis tick and the erythema migrans rash associated with Lyme disease