In what developmental stage does Ochlerotatus trivittatus overwinter?

The overwintering stage of Ochlerotatus trivittatus, commonly known as the three-striped mosquito, is indeed in the egg stage. This mosquito species lays its eggs in areas that will not be submerged during the winter months, typically in areas of floodwater. The eggs can withstand desiccation and remain viable until conditions become favorable for hatching, usually in the spring when temperatures rise and water becomes available.

This adaptation allows them to survive harsh winter conditions and is a critical aspect of their life cycle. The ability to remain dormant in the egg form ensures that the species can quickly exploit warm, wet conditions when they return, thus ensuring their survival and continuation of the population.

Other potential overwintering stages, such as adults, larvae, or pupae, do not apply to this species as effectively. Adult mosquitoes may seek sheltered locations to survive winter but are less common for this species. Similarly, pupae and larvae would not survive the freezing temperatures that occur in winter, making the egg stage the most suitable and resilient for overwintering.