After seed is harvested it’s brought to mills where it is processed and stored. Along with the harvest come eggs that insects have layed in the field. Birds don't mind the extra protein, but if the eggs hatch they can cause a real problem.
Female Indian meal moths lay tiny eggs (0.5 mm) in or near potential food plants. When conditions are right, larvae or "tiny whitish caterpillars" hatch, eat, and then spin a tiny silken cocoon. The life cycle may range from the shortest period of four weeks to the longest of 300 days. In cold climates, eggs don’t hatch or larvae overwinter and pupate when the weather is warmer. Once the moth emerges from the cocoon, they mate and repeat the cycle.
|Adult in Resting Position|
Meal moths can be difficult to eliminate once they've taken up residence, so a good cleaning is a necessary if you’ve experienced and infestation. Throw out any contaminated bird seed and wash all containers thoroughly. The Wild Birds Unlimited - East Lansing and Okemos, Michigan stores also have the moth pheromone traps. Place one of these non-toxic traps in the garage to inhibit the development of adult moths.
The following are a few suggestions to prevent an Indian Meal Moth re-infestation:
1) Fresh Seed - In warm weather or if you store your seed inside buy no more than 2-3 weeks supply of seed at a time. And never pour old seed on top on new. Moth eggs are inside seed and are just waiting for the right conditions to hatch.
2) Storage Conditions - Store seed in a cool, dry place, or a freezer to prevent moths from hatching. In the winter, the bird seed can be stored up to 3-4 months in a steel can outdoors or in an unheated garage.
3) Sterilize Seed – You can use heat to kill any larvae and eggs that may be in the food. In a conventional oven, spread seed out on a flat baking sheet and cook for 30 minutes at 300 degrees. Sterilizing your seed will not alter the attractiveness of the seed for your birds.
4) Seed Selection – You are less likely to find eggs in seed that has no shell. When sunflowers seeds have their shells removed it also removes almost all eggs. Wild Birds Unlimited No-Mess Blend or Shelled Sunflower seeds rarely carry eggs, but may be re-infested if Indian meal moths are in the home. Nyjer (thistle) and safflower seed are also less likely to be infected initially.
Well perhaps outside seed storage would be the answer. I have considered it for my wild birds, but I have the same issue for my inside birds (lovebird, parakeet). I have tried freezing to no avail, but the outside storage for my outdoor birds may be a good solution. Thanks very much for the answer to my question!