During which months are black fly adults most abundant?

The abundance of black fly adults is most closely associated with the warmer months when environmental conditions are favorable for their life cycle, particularly for mating and reproduction. May and June provide a suitable climate for these activities, which is why this option reflects the peak periods of adult black fly populations.

During these months, the temperatures are typically warm enough to support black fly activity, and the spring runoff from melting snow contributes to optimal breeding conditions in aquatic environments. This timing aligns with their life cycle, as they mature from larval stages in the water to flying adults during the late spring and early summer.

While April might see some black flies emerging, the population is not as high compared to May and June. Similarly, by the time July and August arrive, many black fly adults have completed their life cycle, which means their abundance tends to decline as they may start to die off or become less active as environmental conditions change.