The Tiny: these insects in food!

Most of us have had the rather unpleasant experience of pests hiding in our food, whether at home or in restaurants, supermarkets or fast food. These range from flies and wasps to ants and sometimes even cockroaches. They crawl and fly in or on food and are relatively easy to spot due to their size.

There are, however, a number of insect pests that are difficult to notice because they are so small, especially in the early egg and larval stages, that you may need a magnifying glass to see them. . Many spend a significant part of their lives inside their favorite food. They are collectively called stored product insects (IPS) or stored product parasites.

La menace pour l’industrie alimentaire

These tiny pests cause a great deal of economic damage in the global food industry, from farm to storage, transportation, processing, distribution, and in homes and businesses. They consume, contaminate and spoil a large part of the global food supply, especially in developing countries where poor food storage conditions allow insects to proliferate. It is estimated that stored product insects destroy about 20% of the world’s cereal production each year after harvest.

Insects from stored products can enter the food supply chain at any time from the farm field to the consumer. They can be delivered with food, crawl or fly in an odor-attracting food storage area, and hide in any cracks or crevices and other hiding places around the storage location. They are then waiting to infest the next batch of food that integrates the stock.

A number of these pests are also associated with bird nests and rodents, living in detritus in and around nests. They can then spread from nests to plant or animal products stored in the same building or the buildings nearby.

You may not notice that the food you bought is infested, even if you eat it – check your flour, seed, cereal or other dry food packages closely. It will likely take a large insect infestation in the food for their droppings and shedding to alter the taste and smell of the food. For food processors, however, contaminated ingredients can affect the taste of the product, alter physical properties, and clog production machines, resulting in significant financial losses.

What are stored product insects?

Beetles and weevils: they form the most important order of the animal kingdom, the beetles, with about 400,000 species. Adults and larvae have biting mouthparts and a relatively small number of species are adapted to feed and reproduce in a range of dry plant and animal products that humans use. A few hundred species are formidable pests. Most of these beetles and weevils can fly as adults to find new feeding and breeding sites. Some, however, do not have functional wings and rely on human activity to stay near an appropriate food source.

Mites: The Lepidoptera order includes about 180,000 species of butterflies and mites, but only about 30 are notable pests of stored products. Adult mites do not have biting mouth parts – they suck liquid food – but the larvae have biting mouth parts for eating solid food and can chew certain types of packaging. Winged adults, of course, are the most mobile and can fly to suitable food sources to lay their eggs.
Dust mites: these are not insects, but arachnids – closely related to spiders and ticks – and the smallest pest less than 1 mm in diameter in adulthood. Not only do they contaminate and spoil food, but they can also cause allergic reactions. They can infest a wide variety of foods, but some are beneficial, being beetle parasites or weevils that infest food.

What do insects eat from stored products?

Insects from stored products can infest all dry and canned food and organic products, including grains, nuts, grains, pasta, cheeses, dry meats, wool and leather. They can be classified according to the plant and animal products they infest.

The University of California Riverside and the Institute of Environmental Health in England have classified insects in food into groups with similar habits in how they infest stored products. Here are the categories and some of the most important pests – some feed on several types of food and therefore appear in more than one category.

Nuisibles des grains entiers

These are some of the most economically important pests of food in the world, as they are capable of destroying large quantities of stored grain. Some such as the grain trogodermis are considered an invasive species worldwide and subject to quarantine in countries like the United States and Australia:

  • Grain calendar, Sitophilus granarius
  • Rice stump, Sitophilus oryzae
  • Grain capuchin, Rhyzopertha dominica
  • Cadelle, Tenebroides mauritanicus
  • Cereal alucite, Sitotroga cerealella
  • Grain trogoderm, Trogoderma granarium

This group of insects feed on broken grains, flour, cereals and a wide range of other dried plants and processed products. It includes some of the most important pests in grocery stores and homes. Since there will always be broken grains in any grain store, they may also be present in unprocessed whole grain stores and containers.

  • Brown flour beetle, Tribolium confusum
  • White mealworm, Tenebrio molitor
  • Common Beetle, Cryptolestes pusillus
  • Grain Beetle, Lophocateres pusillus
  • Rice mealworm, Caulophilus oryzae
  • Flour moth, Ephestia kuehniella
  • Dried fruit moth, Plodia interpunctella
  • Australian Ptine, Ptinus ocellus
  • Variegated Ptine, Ptinus fur
  • Beetles beetles (Dermestes, Anthrenus, Trogoderma, Attagenus) generally scavengers,

they are common in warehouses, attics, mills and food packaging factories.

Pests of meat and cheese

Les coléoptères dermestes sont généralement des charognards et s’attaquent aux viandes et aux fromages conservés et transformés. Ils peuvent se reproduire dans les tapis, les peaux, les nids d’oiseaux, d’insectes et de rongeurs – ils sont même utilisés pour nettoyer les squelettes des animaux dans les musées. Les larves peuvent creuser dans le bois ou d’autres matériaux durs pour se pupifier.

  • Nécrobie à pattes rouges, Necrobia rufipes
  • Dermeste du lard, Dermestes lardarius
  • Dermeste noir, Dermestes ater
  • Dermeste des peaux, Dermestes maculatus

Various insects in food

These species have been found in a wide range of foods in addition to what is indicated in their name, including cereals, flours, nuts, seeds, chocolate, spices, beans, tobacco, dried fruits.

  • Serrated grain beetle, Oryzaephilus surinamensis
  • Oilseed seed beetle, Oryzaephilus mercator
  • Lasioderm tobacco, Lasioderma serricorne
  • Breaded tendrill, Stegobium paniceum
  • Cocoa moth, Ephestia elutella
  • Almond moth, Cadra cautella

Pests of dried fruits

These stored product insects feed on a wide variety of foods. But they primarily attack dried fruits that are stored for a long time or that enter fermentation or that deteriorate due to poor storage. Some species feed on the mold that forms on rotting food.

  • Dried fruit moth, Plodia interpunctella
  • Mediterranean flour moth, Anagasta kuehniella
  • Almond moth, Cadra cautella
  • Dried fruit moth, Vitula edmandsae serratilineella
  • Nuts moth, Aphomia gularis
  • Serrated grain beetle, Oryzaephilus surinamensis
  • Oilseed seed beetle, Oryzaephilus mercator
  • Fruit nitrite, Carpophilus hemipterus
  • Tobacco beetle, Lasioderma serricorne
  • Flour tribolium, Tribolium species
  • Small grain borer, Cryptolestes ferrugineus
  • Harmful nuts :
  • Brown flour beetle, Tribolium confusum
  • Red flour beetle, Tribolium castaneum
  • Serrated grain beetle, Oryzaephilus surinamensis
  • Oilseed seed beetle, Oryzaephilus mercator
  • Dried fruit moth, Plodia interpunctella


Pests of legumes – beans and peas
Bruchs, such as bean weevil, Acanthoscelides obtectus. It was originally a tropical species, native to Central America, but has spread around the world in food shipments and has become an important pest in many countries.

Acarians :
Dust mites are widely distributed worldwide, in many habitats, in soil, on plant waste, bark, as parasites of plants, birds, mammals and insects, as well as in bird nests, rodents and bees. They are arachnids, not insects, which makes them closer to spiders, ticks and scorpions. They are the smallest pests in adulthood, less than 1 mm in length.

Several species are major pests of flour, cereals, seeds, nuts, cheese and dried meats. Some also feed on fungi that thrive on food when stored in humid conditions and others are parasites of some of the pests listed above. At least two species are also deliberately grown on certain cheeses to give a very specific flavor.

Dust mites produce allergens that can affect people who handle infested grain and flour, as well as infested dust and furniture in the home.

  • Ciron flour, Acarus siro – the best known of the mites, attacking, as its name suggests, flour and grains but also other foodstuffs. It is also used to flavor French Mimolette cheese
  • Cheese mite, Tyrophagus casei – a pest of cheese, cereals and flour, but it is also grown for making certain cheeses for the specific flavor they create, such as the German Milbenkäse cheese
  • Mold mite, Tyrophagus putrescentiae — found in foods with high fat content such as seeds, nuts, cheese, ham, and also on grains and flour. It causes skin irritation called itchy grocers
  • Dried fruit mite, Carpoglyphus Lactis – found on dried fruits such as figs, dates, raisins and fermented foods
  • Storage mite, Glycyphagus domesticus – feeds on flour, sugar, cheese, tobacco, wheat, hay, mold and is found in honeycombs and birds.

Signs of the presence of insects in food

It is important to carry out detailed inspections of stored products and storage areas in order to identify an infestation as soon as possible. Review incoming deliveries and regularly check food that has been stored for some time. Ensure that suppliers and carriers also have a strict inspection and monitoring procedure.

The common signs of an insect infestation of stored products are:

  • A product shows signs of damage: for example, grains, or nuts have small holes
  • Live or dead insects in food: adult insects, eggs, larvae, droppings, pupae or silk cloth in food or packaging
  • Food spills: contain adult insects, larvae, pupae or silk webs
  • Holes in the package: they can be very small – larvae or webs on the outside of packages or bags
  • Cabinets and shelves, in the storage area, or near the machines there are adult insects, larvae, droppings, pupae or silk webs
  • Beams and window sills: in areas where food is stored, there may be larvae, pupae or silk webs
  • Caught in traps: insects from stored products are caught in insect traps or electrical insect killers
  • Infested machines: adult insects, larvae, nymphs or silk webs are in crevices or hidden spaces