Hey everyone,
I’ve been struggling with a severe bag moth infestation in my maple and pine trees. These pests have covered branches with their spindle-shaped silk bags, causing noticeable defoliation and stressing my trees. I manually removed dozens of bags last fall, but this spring, the larvae reappeared in full force. I’m hesitant to use harsh chemicals due to nearby vegetable gardens and wildlife ponds.
Manual removal is still your best bet if done strategically! Use pruning shears in late fall/winter when the bags are dormant. Burn or freeze the bags afterward—never just toss them. For high branches, I attach a hook to a pole. Consistency is key!
@EcoWarrior101 Thanks! How often do you check for new bags? I’m worried about missing them in dense foliage.
Monthly checks from October–March. Wear gloves—larval hairs can irritate skin. Bag moths rarely reinfest treated areas if you’re thorough!
Try Bacillus thuringiensis (Bt)! It’s an organic bacteria spray that kills young larvae without harming bees or birds. Spray in early spring when larvae hatch. Reapply after rain. Saved my apple trees!
@GreenThumb88 Intrigued! Does Bt work on mature larvae too?
Only effective on young larvae (under 1 cm). For adults, pair with manual removal.
Attract chickadees, woodpeckers, and parasitic wasps! Install nest boxes and plant native shrubs (e.g., serviceberry) for shelter. I also avoid insecticides, birds won’t feed where pesticides are used.
@NatureLover64 Smart! Any tips to lure wasps?
Plant dill, fennel, and yarrow. Wasps lay eggs inside bags, destroying larvae naturally!
Neem oil works wonders! Mix 2 tbsp per gallon and spray trees at dusk (avoids leaf burn). Add a few drops of dish soap as a spreader. Reapply every 7–10 days until eggs diminish.
@EarthFriendlyTom Is neem safe for young saplings?
Test a small area first. Avoid new growth under 1 ft tall, oil can smother tender leaves.
Chemical sprays like spinosad (derived from soil bacteria) are low-toxicity. Apply in late spring. Never spray during blooms, it harms pollinators. Use as a last resort only!
@PestControlExpert Can spinosad affect fish in my pond?
Avoid spraying within 30 ft of water. Spinosad degrades quickly but can harm aquatic larvae.
Destroy leftover bags by November. Use dormant oil spray in winter to suffocate eggs on bark. Keep trees healthy, stressed trees attract more moths!