Argentine Ants Swarming in Los Angeles

Subject: Los Angeles: black tiny fly likes water w short clear wings
Location: Los Angeles, CA
April 28, 2015 10:33 pm
Thank you so much for all of your service throughout the years. I often make donations & spread the word!
This latest bug is stumping me: We live in east Los Angeles near Pasadena & the SGV (inland)- tonight I noticed approx 20-30 fruit-fly-esque bugs dead or dying in the bathroom sink. They seemed to be coming in through a tiny opening in the bathroom window, so my husband went to the roof to check it out. He said there are thousands on our roof!! He’s spraying now but we can’t find anything similar-looking enough online.
They seem to obviously be attracted to water but do not look like drain bugs.
(We’re so worried they’re termites but they don’t have long wings)
Signature: Gratefully, Meg

Argentine Ant Alate
Argentine Ant Alate

Dear Meg,
The person who can solve your infestation problem will probably win a Nobel Peace Prize as the solution will improve the quality of life for Californians, the people of Japan and the inhabitants of the Mediterranean, as those are the three places where super-colonies of Argentine Ants,
 Linepithema humile, are making millions of people’s lives miserable, especially in hot summer months when 1000s of Argentine Ants invade homes in search of food and water.  Your images are of winged reproductive queen and king Argentine Ants, known as alates, on their nuptial flight and according to BugGuide:  “Winged queens mate once with a winged male, after which they can continuously produce fertile eggs for as long as 10 years- until death. Unlike most ants, several productive queens of this species can share the same colony, with one or more leaving with some of the workers to form a new colony when it gets crowded (this is known as ‘budding’).”  Here are some good images on BugGuide for comparison.

Argentine Ant Alates
Argentine Ant Alates

6 thoughts on “Argentine Ants Swarming in Los Angeles”

Leave a Comment