Knowledgebase
"worms"/caterpillars and webbing inside peanuts and sunflower hearts and black oil sunflower seeds #815180
Asked October 25, 2022, 12:31 PM EDT
Carroll County Maryland
Expert Response
We agree these are probably moth larvae (one of the typical "pantry pests" most likely, such as Indian meal moth) and they can be common in dry food sources like bird seed that are not sealed well to prevent insect entry. Don't bring any bird seed into the house or the larvae or adult moths might wander and infest stored human or pet food as well.
The birds and other animals will not be harmed by eating seed contaminated with the larvae; if anything, it's a bonus of more protein they will gladly consume since many wild animals eat insects. We do not know how webbing impacts them all but plenty of their natural prey items (other wild insects and spiders) use silk and they surely have a way of dealing with it, if it bothers them at all. Some birds even tear apart communal caterpillar nests (like those made by tent caterpillars and fall webworms) to eat the caterpillars sheltering inside, so insect silk is probably a non-issue for them.
We suggest you not intentionally feed raccoons, though, since they can be carriers of infectious organisms that can harm humans if something is contaminated with their droppings. Raccoons do quite well in suburbia without deliberate aid from us. You do not want raccoons associating you with food. Plus, if you put up bird houses, these dexterous and clever opportunists can raid nest boxes of eggs or nestlings, so this is another reason to not encourage them to seek food in your yard if you wish to support your local birds. Attracting a variety of animals to a common feeder has its own risks of spreading disease or parasites from one animal to another (even when cleaned regularly), and many bird feeder users will bring in their feeders overnight so as not to attract raccoons or possums (or rats/mice, which also might be visiting fallen seed piles at night). As a lower-maintenance alternative, you may want to gradually add more native wildlife-attracting plants to your property as space or budget allows to serve as natural food sources instead, which will keep them from being as concentrated at a feeder while also being a reliable source of fresh food that might be more nutritious for them.
Miri
Hi Miri:
Thanks for the quick reply to my question above.
Since the larvae are pests and since I can easily separate the larvae which are with my seeds, would it be better to kill them as opposed to putting them out for the birds which is what I have been doing? I ask because if the birds do not get to each and every one of the larvae and one becomes a moth, I am assuming that the moth being a non-native insect will simply infect more seeds.
I have raised possums years ago and I do love those animals. In the morning I see their distinct looking "possum poop" (which I clean up and dispose of). So I do want to continue to feed them nightly. (I feed them on ground feeders which are rectangles with screening for easy cleanup of spent seeds and other items.) And of course, squirrels are at every bird feeder available. So they too might pick up some of the spider web-like threads attached to the feed. However, I do try and pull those threads off the individual nuts and seeds before putting them on the screen feeders. Per the raccoons --- you need not worry though I appreciate your good advice about why not to feed them. I had seen raccoons only once or twice all of last winter and springtime. But even if they show up only once or twice a year, I mentioned their presence to you since I don't want to put anything out that could make them ill either.
Per planting native plants as food sources: We have so many MD native perennials that we have been giving them away every spring and fall for about 25 years now. We do this to help the wildlife that live where our plants will be planted. But since they are flowers, they do not provide much if any food for the possums or squirrels. If you can reply with which MD native plants will provide food for the possums and squirrels, especially in the winter, I will be glad to add those plants to our very large gardens.
Thanks,
Jim
You can sort them out of the seeds and kill them if you prefer. If these are Indian Meal Moth (as opposed to a different species) their cold tolerance is limited and any escapees may die over the winter anyway. As a global pest (for humans, at least), it's well-established in just about every part of the world already so escapees would similarly not necessarily pose a threat to our local ecosystem.
Below are ideas for locally or regionally native plants that would draw birds or wild mammals, though even those that attract primarily insects can be of value to them since many animals include insects as part of their diet. We'll focus on some that produce berries/fruit or nuts. You can find information about their preferred environmental conditions in publications like this one from the U.S. Fish & Wildlife Service: Native Plants for Wildlife Habitat and Conservation Landscaping.
- Common Persimmon (Diospyros virginiana)
trees are male- or female-flowered, so only the female trees fruit if pollinated by a male; enough wild male persimmons might be in nearby woods that you'd only need to plant a female; fruit is attractive to possums, raccoons, skunks, birds, and other animals - Pawpaw (Asimina triloba)
trees are not self-pollinating so while there are no male- or female-flowered trees, one tree won't fruit by itself; cross-pollination with another pawpaw is needed for fruiting on each; best as an understory tree in part sun / part shade; fruit is attractive to possums, raccoons, foxes, birds, and more - American Beautyberry (Callicarpa americana)
- Silky Dogwood (Cornus amomum), Gray Dogwood (Cornus racemosa), Redosier Dogwood (Cornus sericea), Flowering Dogwood (Cornus florida), Pagoda Dogwood (Cornus alternifolia)
- American Beech (Fagus grandifolia)
- American Hazelnut (Corylus americana) and Beaked Hazelnut (Corylus cornuta)
- Blueberry (Vaccinium, several species) and Huckleberry (Gaylussacia baccata)
- American Holly (Ilex opaca), Winterberry Holly (Ilex verticillata), Inkberry Holly (Ilex glabra)
hollies are either male- or female-flowered, so a male of the same species would be needed to pollinate any females for berry production - Spicebush (Lindera benzoin)
- Red Chokeberry (Aronia arbutifolia) and Black Chokeberry (Aronia melanocarpa)
- Beach Plum (Prunus maritima), American Plum (Prunus americana), and Chickasaw Plum (Prunus angustifolia)
- Sumac (Rhus, several species)
- Pasture Rose (Rosa carolina), Swamp Rose (Rosa palustris), Virginia Rose (Rosa virginiana)
- Allegheny Blackberry (Rubus allegheniensis)
- Elderberry (Sambucus canadensis)
- Mapleleaf Viburnum (Viburnum acerifolium), Arrowwood Viburnum (Viburnum dentatum), Witherod Viburnum (Viburnum nudum), Blackhaw Viburnum (Viburnum prunifolium)
usually need to be pollinated by another individual of the same species since they are not self-fertile - Serviceberry (Amelanchier, several species)
- Hickory (Carya, several species)
- Black Walnut (Juglans nigra)
- Fringetree (Chionanthus virginicus)
either male- or female-flowered, so needs a pollinator also - Oaks (Quercus, many species)
- Green Hawthorn (Crataegus viridis)
- Cucumbertree Magnolia (Magnolia acuminata), Sweetbay Magnolia (Magnolia virginiana)
- Sweet Crabapple (Malus coronaria)
- Black Willow (Salix nigra)
Miri