Kitchen Invasion | Borneo Online Newsletter
CNA – Has your home recently been invaded by tiny gray butterflies, flapping erratically around your kitchen? Have you spotted suspicious webs in a cereal box? You may be sharing your dried food with pantry moths (also called plodia interpunctella).
Although several species of moths can live and breed in our homes, the pantry moth (also known as the “Indian flour moth”) is one of the most common unwanted moths.
Pantry moths are found on every continent except Antarctica. They feed on rice, grains, flour, pasta, cereals, dried fruits, spices, seeds, nuts and other dried foods. Their fondness for dry foods makes them a major pest in food storage facilities. So how did they get into your home and what can you do to get rid of them?
LARGE QUANTITIES OF SILK WEBBING AND FECES
Like other moths, pantry moths have four distinct life stages: egg, caterpillar, pupa, and adult. The first sign of a pantry moth infestation is often the sight of adult moths flying in an erratic zigzag path around our kitchens.
Adults of the pantry moth have gray wings with bronze or tan bands near the wingtips.
Although they can be bothersome, adult butterflies do not feed at all. The problem arises when female butterflies lay their eggs in or around our food.
The tiny eggs hatch into barely visible cream-colored caterpillars, small enough to crawl into poorly sealed food containers. There they begin to feed.
As they grow, the caterpillars produce large amounts of silken webs and feces, both of which can contaminate food.
Once a caterpillar reaches full size, it leaves the food in search of a safe space to cocoon, usually a crack, container lid, crevice, or corner. Sometimes they end up in the hinges of a pantry door. A few weeks later, an adult butterfly emerges from the cocoon, ready to begin the cycle again.
HOW DID PANTRY MOTHS GET INTO MY HOME? AND WHY ARE THEY MORE COMMON LATELY?
Unfortunately, chances are you brought them home yourself. Although pantry moths can enter through doors and windows, most infestations probably begin when we inadvertently bring home eggs and caterpillars in our dried foods.
Kitchens full of unsealed containers and spilled food create an irresistible assortment for female butterflies looking for the perfect spot to lay their eggs. Like many insects, pantry moths grow faster in warmer temperatures.
In warmer temperatures, females also lay more eggs and caterpillars are more likely to survive to adulthood.
But prolonged exposure to temperatures above 40 degrees Celsius is deadly to eggs and caterpillars.
While pantry moths can be found any time of the year, the warm temperatures of late spring and early summer are often perfect for supporting rapid population growth.
HOW TO GET RID OF PANTRY MOTHS?
First, eliminate their food sources. Dry goods should be stored in sealed, airtight containers with tight-fitting lids.
To prevent eggs and caterpillars from hitchhiking while shopping, place dried foods in the freezer for three to four days; this should kill any eggs and caterpillars that may be present.
If you already have an infestation, carefully inspect all potential food sources, including spices, grains, dry pet food, pasta, seeds, nuts, tea, dried flowers, and fruits dry.
Pantry moth caterpillars are hard to see; look for the silken web they produce, which can cause food grains to clump together. These webbed tufts are often more visible than the caterpillars themselves.
Infested food should be discarded or placed in the freezer for three to four days to kill eggs and caterpillars.
Clean up and dispose of any food spills on shelves, under toasters or behind storage containers. Even small amounts of food can support thriving caterpillar populations.
Caterpillars can travel considerable distances to find a safe place to cocoon, so be sure to check shelves, walls, crevices, and ceilings. Moth cocoons can be removed by wiping them with a damp cloth or with a vacuum cleaner.
Proper cleaning and storage of food is the best way to end a pantry moth outbreak.
Sticky moth traps are commercially available and can be used to monitor and reduce the moth population.
Pantry moth traps — a triangular cardboard covered in thick, sticky glue — are baited with a chemical that mimics the smell of a female pantry moth.
The males are drawn to the trap and become hopelessly glued to the glue. Since sticky traps only target males, the traps are unlikely to stop an outbreak on their own; always use them with proper food storage and careful cleaning.
Insecticide sprays are unlikely to be effective because pantry moth caterpillars and eggs are protected in food containers.
Pantry moths are also resistant to a range of insecticides, making them ineffective. Insecticides should never be applied on or near food.
WHAT IF I EAT EGGS OR DISEASE LARVAE?
While it may be disconcerting to find tiny caterpillars in the cereal you’ve been enjoying all week, accidentally eating pantry moth caterpillars is unlikely to cause any health problems.
Given their frequency in stored foods, you’ve probably unknowingly consumed many moth eggs and larvae.
Thank goodness caterpillars are generally an excellent source of protein.