Eurasian mealworms in Elverta, Sacramento County, California

We received an email about what appears to be an outbreak of Eurasian mealworms in Elverta, in Sacramento County, California.

Cindy, the homeowner, sent photos, posted below, and said “For the last two summers now we have them falling from any ceiling opening into our house! They drop down from the attic from any light fixture and sprinkler heads. They are also all around the exterior of our house.” Cindy also observed: “They do seem to be worse on the back patio where we have a porch light so I do think they are attracted to light. When they land on our floors they find something to hide under. So they will gather under our rugs and floor mats.” At this Elverta location, the home is a manufactured house, and there is no accessible attic.

Her observations match what we have heard from Sheri and Lori, in the Sonora area, that the larvae appear to be attracted to lights, and that the larvae hide under things like rugs and mats. At Sheri’s house, in Tuolumne County, you could find the larvae under artificial turf, outside, also.

The mealworms were dropping from the ceiling, through the holes for light fixtures. The homeowners placed baggies under the lights and collected a great many mealworms.

Mealworms collected in a baggie, placed below a light fixture in the house. Many mealworms are falling through the hole. — Mealworms collected in a baggie, placed below a light fixture in the house. Many mealworns are falling through the hole.

Eurasian mealworms hiding under a carpet, in the house.

Adults beetles. These were just outside the back door.

Eurasian mealworms, larvae and adults, under a door mat by back door.