Return of the pantry moths
Hello, we had a big pantry moth infestation that began last June and ran until November of the same year. They originated in some of the food in our pantry, so we cleaned out the entire pantry and cleaned all surfaces, as recommended. By the time we discovered them, they had moved into two of the three bedroom closets/bathrooms and kitchen area. We've kept traps up in the house since then and have not seen any new moths since November, until about 2 weeks ago. We put all new traps out and have safeguarded our food again. I'm seeing them in our office in addition to the aforementioned places, and unfortunately we just found one in the pantry this morning.
Although they have appeared in our closets, they are definitely pantry moths.
My question is, how long can eggs last before they hatch? Is this a recurrence of our old infestation, or a new one?
We have a new-build house, and I might be a bit paranoid but I'm wondering if it's possible for them to come through the ductwork. It seems so suspicious that they're living in our closets and bathrooms in addition to the kitchen, but not really in our other living spaces.
Tarrant County Texas
You say you put out traps. The commercial pheromone traps for Indian meal moth and related moths are very powerful and will draw moths from all parts of a home, even sometimes from outside via chimney or other openings. I would recommend checking the areas carefully (which it seems like you've already done) and avoid using any traps where there is obviously no food (no need for them there anyway). Use any moth traps in a home sparingly, and do not put near open doors, chimneys or vents where outdoor moths might be drawn into the house.
Thank you for the help. We removed all traps except a single trap in our pantry with the food. We have been moth free for probably 6+ months until last week. We check the trap regularly and sure enough there was a new moth caught. Within days we began seeing one or two moths in other parts of the house. This is very similar to last year's reemergence but we have not put our any additional traps. Does the fact that the moths return in spring indicate they are not coming from inside the house? The pantry only has an overhead light. How are they getting in? Through the attic? How long do the pheremones from the traps traps remain in the rooms we removed traps from? How can we find the source and eliminate it? Sorry for all the questions. We are at our wit's end. Thank you for your help.
You could be drawing in moths from outdoors, or perhaps some stragglers, late emergers, from last fall's infestation. Pheromone traps are just tools to alert you to the possibility of infestation. Commercially, in a warehouse, they can also be used to pinpoint a location of highest infestation--not so much in a home.
The traps are incredibly powerful, so they could be just attracting outdoor moths. Most likely entry points are doorways, windows, chimney (make sure flue is tightly closed)--less likely attic.
Don't panic. Traps may not be a good idea for your home. I'd suggest removing the remaining trap and see if you are continuing to see moths in the house. If not, no problem. Also, check again for any possible overlooked food sources (pet food or bird seed, nuts, or other grain-based foods) that could be producing small amounts of moths.