7 Facts About Meal Moths
December 29, 2018
If meal moths, or Indian meal moths weren’t such pests they would be overlooked. They are tiny and drab and nothing like their large and beautiful cousins the luna or cecropia moth. The saddest thing about them is that the adults don’t eat at all even as they breed non-stop. It’s their caterpillars that chomp their way through the pantry. Here are seven other facts about meal moths:
1. The Caterpillars Can Chew Through Plastic
Meal moth caterpillars can chew through plastic bags or cardboard boxes to get at your breakfast cereal or buckwheat flour. Very few other larvae can do this.
2. They’re Everywhere
Meal moths are found on every single continent save Antarctica.
3. They are Hard to Kill
Certainly, caterpillars and moths are easy enough to kill as individuals. But wiping them out wholesale is hard because it is tricky to put pesticides on food that people eat. Even when they are exposed to pesticides, meal moths quickly develop a resistance and pass it down to their young.
4. Larvae Drag Silk Behind Them
One characteristic of the meal moth caterpillar is that they drag threads of their own silk behind them as they move around. The appearance of silk webs is one way you can tell that you have an infestation. These tangles of silk foul the food because they hold cast off skin, empty eggshells and frass.
5. They Don’t Need it to Be Too Hot to Reproduce
A meal moth only needs temperatures of about 50 degrees Fahrenheit to start reproducing. Each female lays about 100 to 300 eggs right on the food source.
6. The Life Cycle is Between 40 to 55 Days
After the egg is laid, it usually takes 40 to 55 days for it to become an adult moth though the time can vary widely. Most of that time is spent eating, for the egg hatches two days to two weeks after it’s laid. After that, it takes two weeks to a year for the larva to pupate. After that, the caterpillar spins a cocoon around itself and never eats again. The adult emerges from the cocoon four to 30 days later. Adults live for a little less than a week to a little less than a month, all the time mating and laying eggs.
7. They’re Not Native to India
The Indian meal moth gets its name because cornmeal, or Indian meal is one of its favorite foods.
The fecundity and ubiquity of the meal moth makes it hard to eradicate. The smallness of its eggs and its newly hatched larvae make it hard to find until you open up a bag of something and notice that’s something is wrong. Still, it is an interesting animal to study, if only to learn how best to kill it.