Apr 5, 2011 – Wandering Worms
QUESTION:
I need to identify a worm in my customer's kitchen. I'm sorry I dont have a pic. These are on the ceiling, and then over time turn into some kind of moth. They are clear to light brown or tan with a red head. I have run into these once before, but it has been a long time. I can't remember where I looked them up, so I hope you can help. I do remember they either came in with or they are attracted to cake mix, flour, cornmeal, etc. Thanks so much for your help!
ANSWER:
I will go out on a limb and offer a suggestion, but I still throw out that caution that making a firm ID from a description is always risky. I'd hate for you to take an incorrect ID from me and run with it, perhaps heading the wrong direction in a control effort.
However, your description does fit the possibility that these are Indian Meal Moth larvae, and if you are seeing the adult moths then the ID should be very simple. The adult IMM has narrow forewings, and the inner half of the wings is light tan and the outer half a coppery red color. The larvae are wanderers once they reach maturity and are ready to pupate. They commonly leave whatever it is they are infesting and wander short to long distances to find some cozy corner or crevice in which to make their cocoon, and then pupate within it. The silk cocoon is sort of loosely woven, and you can see the orange pupa inside. You may find the larvae walking just about anywhere within an infested house, so they could be well away from whatever it is they are infesting, and finding the infested material is absolutely critical to controlling these pests, as it is with any "food" pest.
I put the word "food" in quotes, because stored products pests are pretty diverse in their food choices, and the IMM leads the way. It will feed on virtually ANY grain-based food product in the kitchen if it has or creates access to that food. This includes pet foods, baking goods, flours, crackers, spices, cereals, etc. It also commonly feeds on dried fruit and on dry flower arrangements, so the source might not even be in the kitchen. A couple of decades ago it was a fad to make shadow boxes with glass fronts, and in the many little cubby holes inside you put colored rice, beans, grains, etc. as a decorative arrangement. These things were definitely good for our business. Or, the little "granny" dolls with dried apples as heads, or baked rolls in odd shapes used as decorations, including Christmas ornaments. It's amazing what we provide as food for insects, and by golly the insects will find it. Certainly rodent baits in attics or walls are another common source, as the anticoagulant in the bait has no effect on an insect.
So, get the positive ID on this first, and then do some reading about the pest to see what the likely food resources could be. Do NOT spray or fog anything until you have found the source, and it pays not to stop with the first one. I once found IMM in about a dozen boxes of food in a customer's kitchen cupboards. If they desperately want to save and eat the food, rather than throwing it away, it could be placed in the oven at about 130 degree heat for an hour and all bugs will be killed. Somehow, though, I doubt they'll go for this. Find the infested materials, place them in sealed plastic bags for disposal, vacuum the surrounding areas thoroughly, and if you still have wandering larvae or moths they can be vacuumed or a directed treatment of a residual insecticide can help intercept them. As often as not though, pesticide applications may not be necessary once you remove the infested material.
I need to identify a worm in my customer's kitchen. I'm sorry I dont have a pic. These are on the ceiling, and then over time turn into some kind of moth. They are clear to light brown or tan with a red head. I have run into these once before, but it has been a long time. I can't remember where I looked them up, so I hope you can help. I do remember they either came in with or they are attracted to cake mix, flour, cornmeal, etc. Thanks so much for your help!
ANSWER:
I will go out on a limb and offer a suggestion, but I still throw out that caution that making a firm ID from a description is always risky. I'd hate for you to take an incorrect ID from me and run with it, perhaps heading the wrong direction in a control effort.
However, your description does fit the possibility that these are Indian Meal Moth larvae, and if you are seeing the adult moths then the ID should be very simple. The adult IMM has narrow forewings, and the inner half of the wings is light tan and the outer half a coppery red color. The larvae are wanderers once they reach maturity and are ready to pupate. They commonly leave whatever it is they are infesting and wander short to long distances to find some cozy corner or crevice in which to make their cocoon, and then pupate within it. The silk cocoon is sort of loosely woven, and you can see the orange pupa inside. You may find the larvae walking just about anywhere within an infested house, so they could be well away from whatever it is they are infesting, and finding the infested material is absolutely critical to controlling these pests, as it is with any "food" pest.
I put the word "food" in quotes, because stored products pests are pretty diverse in their food choices, and the IMM leads the way. It will feed on virtually ANY grain-based food product in the kitchen if it has or creates access to that food. This includes pet foods, baking goods, flours, crackers, spices, cereals, etc. It also commonly feeds on dried fruit and on dry flower arrangements, so the source might not even be in the kitchen. A couple of decades ago it was a fad to make shadow boxes with glass fronts, and in the many little cubby holes inside you put colored rice, beans, grains, etc. as a decorative arrangement. These things were definitely good for our business. Or, the little "granny" dolls with dried apples as heads, or baked rolls in odd shapes used as decorations, including Christmas ornaments. It's amazing what we provide as food for insects, and by golly the insects will find it. Certainly rodent baits in attics or walls are another common source, as the anticoagulant in the bait has no effect on an insect.
So, get the positive ID on this first, and then do some reading about the pest to see what the likely food resources could be. Do NOT spray or fog anything until you have found the source, and it pays not to stop with the first one. I once found IMM in about a dozen boxes of food in a customer's kitchen cupboards. If they desperately want to save and eat the food, rather than throwing it away, it could be placed in the oven at about 130 degree heat for an hour and all bugs will be killed. Somehow, though, I doubt they'll go for this. Find the infested materials, place them in sealed plastic bags for disposal, vacuum the surrounding areas thoroughly, and if you still have wandering larvae or moths they can be vacuumed or a directed treatment of a residual insecticide can help intercept them. As often as not though, pesticide applications may not be necessary once you remove the infested material.
