Which describes Ochlerotatus canadensis?

• A. Common early-season in MD; eggs overwinter; larvae appear Jan-Feb; one generation per year; caught in light traps & landing counts; vector: dog heartworm.
• B. Only bites humans at dusk.
• C. Found only in urban indoors.
• D. Not a vector for dog heartworm.

Answer: (A)

This describes a temperate, univoltine mosquito with overwintering eggs, early-season emergence, and a recognized role in transmitting dog heartworm. Ochlerotatus canadensis overwinters as eggs and, as conditions warm in late winter to early spring, larvae can appear as early as January or February in Maryland. It typically produces one generation per year in cooler climates, which matches the “one generation per year” note. Surveillance often relies on light traps and landing-count methods to monitor adult populations, aligning with the described catching methods. Most importantly, this species is a known vector for dog heartworm, linking its biology directly to disease risk. The other options don’t fit as well: this mosquito is not limited to biting humans only at dusk, not restricted to indoor urban settings, and it is indeed a vector for dog heartworm.