Part 1, problem reported:
June 22, 2020. Jason Price brought in samples of drugstore beetles infesting a bathroom in a house in Valley Springs, Calaveras County, California. This is unusual, indicating a food source in that area. The problem started, to my knowledge, at least in May of 2020.
It turns out that this house had a bad mouse infestation in the past (prior to the new owners), and we are now going to search for rodent bait or a rodent cache in this area, beneath or within the wall.
Part 2, problem resolved:
Nothing was working to stop the infestation. The beetles kept reappearing after every treatment.
Manager Ryder Richards took on the job. He crawled the subarea and found nothing. That left the bathroom as the area that must have the food source issue. Ryder spoke with the homeowners, and the husband then used a hole saw drill bit to open an access for examination under the bathroom cabinet. Ryder used his cell phone to examine the void, and WOW, what a find!
The camera revealed a huge amount of dog food in the void under the cabinet! Ryder and the homeowner used a shop vacuum to clean out the area. The dog food was old, and, cumulatively, had hundreds and hundreds of little holes.
The homeowners had purchased the house less than a year previously. The house, although very nice, had a history of mouse problems prior to their purchase of it. Apparently the previous owners also had a dog, and a mouse had been moving and caching the dog food in this convenient area. Being that drug store beetles can infest dog food, we presume the previous owners had purchased some dog food that had at least a few drug store beetles eggs in it. The beetles were able to expand their population in this undisturbed setting.
Since the removal of the dog food, there have been no further beetles seen. The problem is resolved. What a great cooperative effort between Ryder and the homeowner.
Photos from part 2:
Photos from Part 1