SAN GABRIEL VALLEY, CA — Residents living in the foothills of the San Gabriel Valley are being warned of a surge in black flies—tiny insects known for delivering a disproportionately painful bite.
Commonly referred to as “buffalo gnats,” these pests have become a recurring seasonal nuisance in Los Angeles County. While they are small, their impact on outdoor activities is significant as they travel in large swarms to find their next meal.
Small Size, Big Bite
Black flies are notoriously difficult to spot, measuring only 2 to 3 millimeters in length. According to the San Gabriel Valley Mosquito and Vector Control District (SGV MVCD), these insects specifically target the eyes and necklines of both humans and domestic animals.
The good news for local residents? Unlike mosquitoes in other regions, black flies in Los Angeles County do not transmit diseases. However, their bites are known to be sharp, painful, and can lead to significant swelling or itching.
Where Are They Coming From?
Unlike many other pests that prefer stagnant puddles, black flies thrive in flowing water.
- Breeding Grounds: They breed in rivers and streams, and their activity is often triggered by scheduled water releases from upstream dams.
- Backyard Risks: The district warns that unmaintained decorative fountains and backyard waterfalls can become unexpected breeding sites if the water is left running continuously.
How the District is Fighting Back
To combat the infestation, the SGV MVCD is routinely treating known breeding sites. They utilize a natural soil bacteria that is highly effective at controlling both black fly and mosquito populations without harming the local ecosystem.
Officials noted that while treatments are currently underway, activity is expected to remain high for the next few weeks as the measures take effect.
How to Protect Yourself: The Only Repellent That Works
If you are planning to spend time outdoors in the SGV foothills, standard bug sprays may not be enough. The district has provided specific guidelines to avoid being bitten:
- Use DEET: According to health officials, DEET is the only repellent proven to be effective against black flies. Ensure it is applied to all exposed skin.
- Cover Up: Wear long sleeves and pants. Because the flies target the face and neck, wearing a fine mesh head net is recommended for those working or hiking in heavily infested areas.
- Maintain Water Features: If you have a fountain or waterfall at home, ensure it is cleaned regularly or turned off if not in use to prevent it from becoming a local breeding hub.
Have you noticed a surge of these tiny biters in your neighborhood? Whether you’re in Altadena, Sierra Madre, or Glendora, we want to hear from you. Share your tips for keeping the gnats away in the comments below!
