Bird watching is a major hobby in America. People enjoy setting out bird feeders and viewing the birds in nature up close. To watch more birds means buying more bird food. If you're like me, you love the birds, but not the birdseed moths.
Whether you enjoy keeping outside birdfeeders stocked with birdseed, or you have a pet bird, birdseed can bring in unwanted visitors into your home. If you see adult moths fluttering around, signs of larvae, and/or cocooned pupae in your birdseed, you can be sure that a bird seed infestation is present.
What are birdseed moths?
Birdseed moths or seed moths get their own name, due to the association of moth outbreaks from birdseed. Birdseed moths are really pantry moths, a moth category that eats human food and is attracted to grains. Technically, a birdseed moth is called Indian Meal Moth, Plodia interpunctella. The terms "birdseed moth" "pantry moth" and "Indian meal moth" will be used interchangeably in this article.
It's not just birdseed, pantry moth larvae love any grains in your home:
- bird seed, cat food, dog food, or animal feed
- dry corn, oats, barley
- flour, rice
For the full list of food that pantry moths prefer, check out Battling a Pantry Moth Infestation.
Encounters with birdseed moths
Ashley Bradford, a professional photographer, documented the larvae, pupae, and adult stage of the Indian Meal Moth (see adjacent photo) on her Flickr page.
A birdseed moth infestation in her own home provided the perfect photo op. Here are the details of the encounter in the photographer's own words,
"I found that caterpillar crawling up the outside of my refrigerator one morning, so I captured it to see what it would become. It seemed odd to find it inside the house like that, but some discussion online had me realizing that my birdseed cache is right under where I found it.
Not long after capture, it pupated, and not long after that, this pretty little moth emerged and I was finally able to ID it [Indian Meal Moth, Plodia interpunctella]. It turns out these moths are widespread throughout the US, traveling just as this one did - in bags of birdseed."
Ashley mentioned in the comments that a second moth was found in the process of pupating directly on the outside of one of the seed bags.
Ashley shared with me "A few years later I had to wage all-out war on them, as I found hundreds in my house only after they had emerged and begun to establish.
That time, the seed bags were next to a closet, and for months I was finding larvae and cocoons tucked into the fabric of jackets, scarves, gloves, and more. I killed every one I found, knowing each one was potential for more. I had to deploy those pantry pheromone traps, which became full of dead moths... I keep birdseed outside now, and I hope that does the trick.
Why birdseed brings pantry moths into your home
Pantry moths are attracted to grains. Grains used in food for pets, such as birdseed, does not have the strict regulations like food for human food consumption has. This means that pet food is not closely observed through the packaging process. In a way, that's good, because it keeps the cost down of the pet food.
As a result of less regulation, impurities or natural contamination, such as insects, will tend to be overlooked. Pantry moth infestations in a home are often tracked to pet food. Unfortunately, pantry moths in birdseed are not uncommon.
Many people who never had pantry moth problems before, suddenly have issues when birdseed is brought into the home. If you are able to, best practice is to not store birdseed in your home, and be constantly vigilant of using pantry moth traps.
Looking for signs of pantry moths in birdseed
The most common pantry moth type is the Indian meal moth. The lifecycle of a pantry moth is covered in Pantry Moths - a Kitchen's Worst Nightmare. It's not pantry moths you are looking for, but the webbing and larvae.
A brief summary of the Indian meal moth lifecycle:
- Egg stage (up to 400 of them to one moth!), takes 2-7 days to hatch
- Larvae stage, the damaging phase to your food supply, lasts 2-3 months
- Cocooned Pupal stage, the larvae spins a web around itself and waits to transform into an adult (15-20 days)
- Adult stage, flying around trying to find a mate, lays eggs and dies (but does not feed), 1-2 weeks
Here is a short video below where the gentleman shows the webbing inside a bag of birdseed, and the larvae crawling.
You might see birdseed pantry moths flying around, but know that their life is short. Did you know they don't even have mouths to feed? Their sole purpose is to find a mate and reproduce - this all happens within 1-2 weeks.
Before dying, the birdseed moths lay their eggs. Seeing the birdseed moth eggs is difficult, as they are microscopic. You may see signs of webbing, which is meant to protect the eggs. The real damage comes when the eggs hatch - larvae are ferocious eaters!
Birdseed moths really love nuts and seeds! If you have brought a bag of sunflower seeds, walnuts, cashews, or peanuts home (especially peanuts in shells), you are vulnerable to an Indian meal moth infestation.
The picture below shows the tell-tale signs of a birdseed moth infestation. You may encounter:
- webbing over the food
- dead or live moths
- crawling larvae (worms-like maggots)
- signs of eaten food, food powder
- paper bags could display small, round bore holes
Probably when you see infestations first-hand, or see images online, you see clumpy little egg-looking debris. These are NOT pantry moth eggs. What you are seeing is "frass" (insect fecal waste aka increment). Remember how mammoth the appetite is of a birdseed moth larvae? Those birdseed larvae are doing everything they can to prepare for the pupal stage of the pantry moth lifecycle (when they go into a brief dormancy without food).
Entomology sites, like the University of Florida Entomology & Nematology Dept. do a much better job explaining frass. So basically, this is pantry moth poop, but that's not technically correct - it's pantry larvae poop. Or you can look really smart and call it pantry moth larvae frass.
Getting rid of Indian meal moth in birdseed
As you can imagine, any bag of birdseed is the perfect feeding ground for the Indian meal moth larvae (the adult flying moth does not eat).
The good thing is that your birds don't care! They actually love to eat worms, maggots, and such. There might even be a few dead moths in the birdseed bag. If you are worried that infested birdseed will make birds sick, don't worry, it won't.
End the pantry moth lifecycle
The problem of infested birdseed is the lifecycle of an Indian meal moth/ birdseed moth. They will continue breeding, laying eggs, and serving up more larvae which are responsible for food damage.
This cycle can continue to happen in the birdseed, but will likely move to other parts of your home. Knowing that the infestation is confined to the birdseed is actually an advantage. You may not be so lucky when it moves to your pantry, kitchen, or other rooms.
Pantry moth infestations must be nipped in the bud! An excellent precaution is freezing the birdseed for 8 days before transferring it to an airtight container. This will assure eggs or larvae have been killed, stopping the lifecycle.
Freezing birdseed is a recommended approach to preventing moths in birdseed. It's not always successful. I've indicated 8 days since some people found 3-7 days not always reliable. Anyone who has a birdseed moth infestation in their home will usually move the birdseed out of the house.
Using birdseed pantry traps to kill males
Moth traps are simply a sticky trap that contain a pheromone specific to food moths (they will not attract clothes moths). By catching adult male moths, they will be unable to breed with the females, thus stopping the Indian meal moth lifecycle.
TIPS WHEN USING PANTRY MOTH TRAPS:
- put the traps in the freezer briefly before opening them, to make it easier to remove the adhesive backing
- wash hands thoroughly before and after handling the trap, especially if you are a smoker - do not to touch the pheromone tabs with hands or the moths will be attracted to your skin
- place one trap in an area at a time.
- replace traps every 3 months or sooner if they fill with moths or become dusty
I assumed that a pantry moth trap would contain the same pheromones as a birdseed trap. Honestly, it just appeared to me as a few companies taking advantage of targeted marketing. However, I came across a user who claimed that "regular pantry month traps... are nearly useless for birdseed moths." I did notice that the MaxGuard company points out that their birdseed pantry moth trap uses extra strength pheromones, which could make all the difference.
TIP: Pantry moths may immediately come out into the open when a pantry moth trap is set out. The adhesive is so strong that that it is possible to chase down moths and catch they on a pantry moth trap sticky pad.
Getting rid of birdseed moths is the same as any other pantry moth. See the complete article here on how to get rid of pantry moths.
Natural birdseed moth deterrents
Natural deterrent products, such as whole herbs such as eucalyptus, lavender, peppermint, rosemary, thyme can be hung in food storage areas, placed in satchets, or use in essential oil form along with lemon, tea tree, and cloves.
A few words on cedar. Cedar is a great natural moth repellent, and you can keep cedar chips, or use cedar oil spray to deter moths. Cedar is not preferred around food, as food can readily absorb the cedar smell, resulting in an awful taste. Maybe birds don't care about that, I would not know!
Cleaning pantry moth areas
To get rid of birdseed moths, the storage space must be cleaned thoroughly. I detail this and add lots of tips in Battling a Pantry Moth Infestation.
- Do NOT throw the birdseed into any garbage can in your house or garage, the infestation will spread.
- If birds are pets and in cages in the house, the cages and feeding bowls must be thoroughly cleaned.
- Vacuum all surface thoroughly. The vacuum bag should be discarded outside of the home. If using a cannister, dump it outside and then thoroughly wash the cannister out.
- Wash down with a soapy hot water solution with vinegar on all surfaces, nooks, crannies. This includes under shelves, behind light switch plates, around door trim, and baseboard molding.
- Put out pantry moth traps to trap the adult male pantry moth; continue until there are no more moth caught.
- Store food in airtight, pantry moth-proof containers, such as for flour.
Check other food stored in the same location; the Indian meal moth infestation could have spread to it as well. I would use clear air-tight containers so you can visually see if anything happens to develop.
According to the University of Florida Entomology & Nematology Dept. if you notice an infestation inside of a jar, and “If the jar had been tightly closed, the infestation would have died, either from lack of air or from a buildup of moisture that would have allowed the development of fungus to destroy the larvae and adults.”
So basically, if you notice an infestation inside of a jar, leave it be. Make sure the jar is really sealed. You can take an extra step and tape up the lid to prevent air from getting to the trapped insects inside. If you're lucky, the problem is only contained to the one jar.
It's your choice if you want to freeze the birdseed so you can still use it, even if you see larvae writhing in it. Like most people, I know that the seed is still useable, but I don't think I want to throw live larvae into my freezer next to my other human food!
Know that if you have an active Indian meal moth infestation, the area must be cleaned FIRST, and then traps added until there are no more signs of adult moths. THEN natural deterrents can be added into the food storage space.
Preventative futures measures against birdseed moths
The ongoing actions to take to prevent birdseed moth infestations:
- freeze the birdseed supply for at least 8 days, consider breaking down into small bags
- keep birdseed in sealed, airtight container
- inspect all human food and pet food before bringing into the home
- routinely inspect human food and pet food storage areas for signs of a pantry moth infestation
- routinely wipe down shelves where food is kept - take extra vigilance to remove crumbs and food dust that can attract egg-laying moths and food-eating larvae
- avoid vacuuming live moths, they can continue to live inside of the vacuum canister or bag - the convenience of sucking up one moth is not worth the time of properly disposing the contents of the bag or cleaning a vacuum cannister
In addition, you can be proactive by continuing to leave out pantry moth traps where you keep your birdseed food. If you keep it in a garage, shed, or barn, hang traps there. Further below I mention natural deterrents that can be used to discourage birdseed moths from laying eggs by your food.
Spread the word on birdseed moths to your bird-loving friends and family! With a little knowledge, an Indian meal moth infestation can be prevented from spreading to the rest of your pantry, kitchen, and home.