Many insects in Merced County resemble mosquitoes at first glance. While they may be a nuisance, most of these mosquito look-alikes do not bite humans, don't spread disease, and are not a public health concern. Knowning the difference can help you identify true mosquito problems and understand which insects are harmless neighbors. 

Common Mosquito Look-Alikes

Crane Flies (Tipulidae) 

• Often called "mosquito hawks" or "mosquito eaters", but despite the name, they don't eat mosquitoes.
• Much larger than mosquitoes (up to 2 inches long) with very long legs
• Feed on plant nectar.
• Totally harmless to people.

Non-Biting Midges (Chironomidae) 

• Resemble small mosquitoes and often appear in large swarms.
• 1/8 inch to 1/2 inch long.
• May be light green, brown, or dark in color with fuzzy antennae.
• They do not bite and are not a disease threat, but can be a nuisance around lights, porches, and windows.

 

Fungus Gnats (Sciaridae) 

• Common in houseplants, terrariums, and greenhouses. 
• 1/10 inch to 1/8 inch long.
• Adults are weak fliers and are attracted to light.
• Harmless but annoying when they emerge in large numbers.
• Letting plants dry out between watering helps control them.

 

Drain Flies (Psychodidae) 

• Also called moth flies, sewage flies, or filter flies.
• 1/16 to 1/4 inches long.
• Small, fuzzy, and often seen near sinks, tubs, and floor drains.
• Breed in the organic film inside pipes.
• Not a health concern, but best managed by cleaning drains thoroughly.

 

 

Mayflies (Ephemeroptera) 

• Found near creeks, rivers, and irrigation canals.
• 1/4 to over 1 inch long.
• Adults are weak fliers and often gather in large numbers near lights.
• Do not bite; their larvae are important for healthy aquatic ecosystems.