Black flies are also called gnats or buffalo gnats. Thirty species of black flies occur in Minnesota. All species are very similar in appearance to each other. Plus sign (+) if content is closed, 'X' if content is open. On the leaves of aquatic plants and objects.
Black flies are active spring through summer and bites are most common during spring. Wear a long-sleeved shirt, pants and a hat to avoid black fly bites. Repellents are not always effective but may provide some help. Black flies are also called gnats or buffalo gnats.
The only way for a recessive trait can result from the test cross, is if the red-eyed fruit fly was heterozygous (Rr). The cross is between a red-eyed fruit fly and a white-eyed (rr) fruit fly. The only way an offspring can have white eyes, is if it inherited a recessive allele from both parents.
When black flies are active they can develop into very large swarms. Black flies use blade-like mouthparts to slash the skin and feed on blood. Bites are concentrated on exposed areas of skin, especially along the hairline, feet, ankles and arms.