Pantry moths
in chocolate.
What can I do?

Like all so-called real moths, pantry moths belong to the butterfly family. This might sound nice in the beginning, but these insects are everything else than harmless flutter things. In comparison to the also bothersome clothes moth pantry moths don’t enjoy the taste of our textiles but they are aimed on nearly all food in our kitchen. Every species has their own preferences. The flour moth (Espestia kuehniella) is the main danger for our beloved chocolate. This storage pest has a size of about 11 to 14 mm, has a silvery-grey colour and lays its up to 500 (!) eggs in flour, grain products like muesli, bakery, legumes, almonds, nuts and, unfortunately, chocolate. The most common of the so-called pantry moths besides the flour moths are the meal moth (Pyralis farinalis) and the Indian meal moth (Plodia interpunctella), all of which belong to the butterfly family of the pyralid moths.

Pantry moths are usually introduced to the household without being noticed and are often found in products with defective packaging. They are famous for their hiding skills and can even bite through thin packaging and overcome the screw threads of storage glasses. They spread in the whole kitchen and storage area quickly because the caterpillars can creep up to 400 metres far. Creeping and jumping are the preferred means of moving for pantry moths because they can only fly short distances. But don’t worry, even if you are no manic for housework: a pantry moth infestation is not the result of cleaning too little.

Like butterflies, the moths develop from egg to larva to pupa to moth. The eggs are usually laid in the respective food that feeds the larvae. During pupation, the characteristic webs occur which cause the food to stick together and which are clear indicator for pantry moth infestation. The grown-up moths live for a maximum of two weeks and lay their eggs in food again – a vicious circle!

To break the vicious circle of constant reproduction of the pantry moths you have to pay attention to a few rules and take action accordingly. You should use sustainable methods instead of using hazardous pesticides.

After checking all (!) food and assessing your situation you should dispose of all affected food. In case of consumption of the webs and moth faeces you risk gastrointestinal disorders, skin problems and allergic reactions. It’s best to freeze the foul food for a few days or to heat it up for two hours at a maximum of 80 °C before disposal. This kills all pests and prevents them from spreading further.

All cabinets should be cleaned thoroughly, vacuumed and washed out with vinegar water, ideally you repeat this biweekly for a while. Dispose of your vacuum bag to be on the safe side. Cracks and areas which are difficult to access can be cleaned with a needle and/or treated with a hair dryer because heat harms or kills the pantry moths in their different stages. Fresh food should be stored in tightly closed containers to prevent a new outbreak.

You can also use beneficial insects to fight pantry moths. Ichneumon flies (Trichogramma evanescens), the natural enemies of pantry moths, are only 0,4 mm big insects, lay their eggs in pantry moth eggs and destroy them by doing so. They can be bought in stores on cards and are also available on the internet. Over a treatment period of 10 weeks online distributors send out the ichneumon flies several times, they perform their job barely visible for the house inhabitants. In case the infestation has ended they disappear by themselves. The only shortcoming: the treatment with ichneumon flies is pretty expensive with a price of 25 € up and is only worthwhile for strong infestation.

To control whether the pantry moths are gone you can buy pheromone traps. They contain a special pheromone that attracts the male pests which stick to the trap. In case no insects are caught you can tell the infestation is over.