How to identify and control flour moths

Verena
Verena
Verena
Verena

I grew up on a small, organic family farm and after a gap year spent working on an American ranch, I started studying agricultural science. Soil, organic farming practices, and plant science are what I am most drawn to. At home, when I'm not in our garden, you can find me in the kitchen, cooking and baking with our harvested fruits and vegetables.

Favorite fruit: Even if a bit boring - apples
Favorite vegetables: Bell peppers, red beets, zucchini, white cabbage

How do you recognise flour moths, their larvae and eggs and how do you prevent them? Read on for our tips and tricks for getting rid of flour moths naturally and effectively.

Light brown Mediterranean flour moth
A flour moth is an unpopular guest in the midst of food [Photo: Jurik Peter/ Shutterstock.com]

Finding small maggots or moths in food is an unpleasant experience for anyone. It quickly ruins your appetite and raises the question where the little creatures came from. Often these storage pests come in the form of flour moths (Ephestia kuehniella). In addition to dry food such as flour, pasta, rice or baked goods, they sometimes feed on dried fruit or mushrooms. Once in the home, flour moths reproduce very quickly, especially when the pantry is well-stocked, which makes getting rid of them difficult – but not impossible. We will show you how to identify and control flour moths and how to prevent future infestations.

Flour moth lifecycle

Flour moths are 1 – 1.4 cm in size. They are particularly active in summer and at night. The eggs and larvae need as much warmth as possible to develop. In good conditions, there can be up to 4 generations a year. Usually, the larvae enter our homes via contaminated food but sometimes moths will fly in through an open window. If they then find an accessible food source, it only takes about 96 hours for deposited eggs to develop into small, voracious larvae. During their short lifespan, female flour moths can lay several hundred eggs! Depending on the temperature, the larvae feed for about 40 days before they reach their final size. They then leave the food source, pupate, and become an adult moth within 9 days that begins to lay eggs again.

How to identify flour moths

Detecting adult flour moths

Adult flour moths are grey in colour with different pattern variations. Due to their plain appearance, they are not always easy to spot. Moth traps are a simple and reliable tool for checking whether you have moths in your home. Pheromone traps such as our Plantura Pantry Moth Traps contain sex attractants that function as lures for male food moths, which then stick to the traps. Should you choose our Plantura Pantry Moth Traps, we will send you 6 odourless glue traps you can simply place in your pantry or affected cabinets. After removing the protective film, the trap is activated and can be used for about 6 weeks.

Pantry Moth Traps 6-pack
Pantry Moth Traps 6-pack
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star-rating star-rating star-rating star-rating star-rating
(4.8/5)
  • 6 odourless, long-lasting pantry moth traps
  • Ideal for detecting infestations in kitchens & pantries early on
  • 100% insecticide-free & non-toxic
£8.99

Detecting flour moth larvae

Damage to food is not caused by the moths themselves but by their larvae. After hatching, they are under 1 mm in size. Just like the eggs of the flour moth, the larvae are hardly visible to the naked eye. Adult moths do not stay this small and reach a length of 1.3 cm when fully grown. During their development, moth larvae do not need a single drop of water and can cover a distance of up to 400 metres, making them astonishing little creatures.

Moth larvae leave both excrement and webs behind in infested food. During their development, moth larvae shed their skin several times and spin webs as they move, leaving behind threads that cause lumps in flour and other food items. Therefore, it is usually a bad sign if you find lumps in dry, finely ground food. The webs are problematic because they can cause condensation and the moisture can either lead to mould or attract flour mites. The good news is that flour moth larvae themselves are harmless and non-toxic – but still not the kind of protein you want to be eating with your breakfast.

Flour moth larvae in webs
Flour moth larvae leave a trail of droppings and webs in infested food [Photo: JSep/ Shutterstock.com]

How to detect flour moths – summary:

  • Adults: 1 – 1.4 cm large moths with brown patterned wings
  • Larvae: maggot-like, up to 1.3 cm long
  • Webs: lumps in food such as flour and cereals

How to get rid of flour moths naturally

Once you have discovered a pest in your home, you will of course want to get rid of it as quickly as possible. The most obvious solution might seem to use an insect spray. However, insecticides contain poisonous substances we would not advise using in a kitchen or near food, so we will show you some safe and sustainable alternatives. Make sure to dispose of contaminated food immediately because it poses a health risk.

Dark brown mill moth
Flour moths can have light or dark colouring [Photo: Tomasz Klejdysz/ Shutterstock.com]

Getting rid of flour moths with ichneumon wasps

The most natural and effective method of getting rid of flour moths is through biological pest control. Ichneumon wasps of the genus Trichogramma have specialised in parasitising moth eggs during evolution. Due to this special adaptation, they are highly effective and have been used and bred for moth control since the 19th century.

For our Plantura Mini-Wasps against pantry moths we use a species of this genus, namely Trichogramma evanescens. They provide a chemical-free, environmentally-friendly and safe means of moth control. Our mini-wasps come in carded dispensers containing 2000 wasps each in different stages of development. They soon hatch and immediately get to work. By laying their own eggs inside the moths’ eggs, they parasitise and thereby kill them. Ichneumon wasps are very discreet little helpers and are hardly visible to the naked eye. As they do not have a sting, they are completely safe for you, your children and pets. You can learn more about them in our detailed ichneumon wasp fact sheet.

All you need to do is place the cards in the affected area and the ichneumon wasps will do all the work. One card covers an area of 1 m², so we recommend using 4 cards for a normal-sized kitchen. Repeat the process 3 times at 14-day-intervals to make sure you have eliminated the infestation entirely. To make sure you always have fresh ichneumon wasps to hand at the right time, we will send new cards right to your doorstep. Soon you will be moth-free and the little ichneumon wasps will die unnoticed as soon as no new moth eggs are available.

Mini-Wasps against Pantry Moths - Natural Moth Control
Mini-Wasps against Pantry Moths - Natural Moth Control
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star-rating star-rating star-rating star-rating star-rating
(5/5)
  • Effective & chemical-free biological control for pantry moths
  • 1 one-time payment for 4 separate lots of mini-wasp cards delivered at 2 week intervals
  • Highest quality parasitic wasps - not harmful to humans or pets
£23.99

Summary: how to use ichneumon wasps

  1. Order your Plantura Mini-Wasps against pantry moths (the quantity of cards depends on the size of your kitchen/pantry – 1 card covers 1 m²)
  2. Place the cards in the affected area for 14 days
  3. You will receive a free follow-up delivery of fresh ichneumon wasps at 14-day-intervals
  4. Repeat the application 3 times

Tip: wipe the affected shelves thoroughly with a damp cloth after application to remove the remains of the ichneumon wasps.

Why pheromone traps are not a control method

Pheromone traps cannot be used to get rid of moths entirely because they only attract male moths and are unlikely to catch every single one. It only takes one male to escape the trap and mate with a few females, who then lay up to 500 eggs each, to sustain the moth population. The use of pheromone traps, such as our Plantura Pantry Moth Traps, is still useful to detect an infestation early on and to check whether your control method is successful. Since the use of ichneumon wasps takes about 8 weeks and the traps release pheromones for 6 weeks, make sure to replace them at least once.

Tip: to be on the safe side, leave some traps in your cupboards to detect a new infestation in time and prevent greater damage.

Flour moths on sticky trap
Sticky traps help with early detection of a mill moth infestation [Photo: off5173/ Shutterstock.com]

What to do after a moth infestation

It is best to dispose of food such as flour, pasta or cereals once they have been contaminated by flour moths. Although the moths themselves are not poisonous, a harmful mould may have formed in the food. Whether or not to throw away non-contaminated food as well to be on the safe side is a personal choice. Another option is to place food in the oven at 60 °C for at least 20 minutes to kill potential moth larvae.

Make sure to clean cabinets and drawers with infested food thoroughly and to wipe them with vinegar and water. This home remedy using vinegar will kill any moth eggs that may have survived. However, should you be dealing with a severe infestation, even vinegar will not do because the moth eggs are barely visible to the naked eye, making it difficult to remove them completely. For this reason, ichneumon wasps are the more thorough method. By the way, food kept in the fridge or freezer is safe because moths can only develop at temperatures above 10 °C.

How to get rid of a moth infestation – summary:

  • Dispose of contaminated food immediately
  • Heat remaining food to 60 °C
  • Use ichneumon wasps for highly effective, biological pest control
  • Wash out shelves with vinegar
  • Use sticky traps only to detect an infestation and to monitor moth numbers

How to prevent flour moths and protect your food

Preventing moths from getting at your food in the first place is easier said than done.

Jars with screw caps
Screw caps without a seal do not keep flour moth larvae out [Photo: BriMor/ Shutterstock.com]

Food packaging made of thin cardboard or thin foil is not a problem for moth larvae. They will simply munch tiny holes into the packaging to get to the food. The hole may be so small you do not even notice it. The cunning caterpillar-like creatures can even make their way into screw top containers. Only thick airtight plastic containers or jars provide reliable protection.

Not only flour moths but also other food moths can cause problems in our homes but similar approaches apply to them as to the flour moth. Getting rid of clothes moths is also possible with ichneumon wasps.

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