22 October 2020

3 things you need to know about Stored Product Insects

Written by Bakang Kganyago

The term stored product insects (SPI) covers a myriad of insects that include beetles, weevils, moths and mites that are found in grains, cereals, dried fruit, nuts, seeds and even tobacco.

I’m sure most of us have found little critters in our cereal and our stored products at least once in our life – not necessarily knowing that they would be the cause for us to throw the food away. These pests contaminate, and will most likely spoil and damage any food into which they come in contact

In one of our previous blog, we discussed a study that Rentokil conducted that states that 60% of businesses which have suffered a stored product insect pest contamination in food reported an annual revenue loss of between 1 and 9%.

In addition, nearly half of the businesses Rentokil surveyed (45%) with a stored product insect problem, reported replacement costs for contaminated raw ingredients such as flour, rice or wheat. 10% of businesses reported additional costs from an SPI infestation in the form of fines or closures.

In this blog we will cover 3 things you need to know about stored products insects: how to identify SPIs in food, which food products do you find SPI’s in and what to do once you have found them.

3 things you need to know about stored products insects:

1. How to identify Stored Product Insects in food:

There are 3 main groups of stored product insects: beetles and weevils, moths and mites. Beetles and weevils have no wings and rely on human activity to find new breeding grounds. You usually find them crawling around infested areas, in and around packaged foods.

There’s a subset of moth species that pose a threat in food manufacturing. The adults don’t have the ability to eat solid food as they lack biting mouthparts, however the larvae can bite through packing and eat solid food. Mites are arachnids and are the smallest of the SPIs, They not only contaminate and taint food but can cause allergic reactions.

What to look out for when identifying them?

The presence of small beetles crawling across counter tops, dead insects, larvae, pupae or silken webbing on food storage bins on shelves.
Holes, larvae or webbing on the outside of food paper or cardboard packaging
Small insects or beetles crawling on the outside of packets or bags, in cracks and crevices around shelves or on machinery or on beams and windowsills

2. In which food products might you find SPIs?

Knowing which stored products are at high risk will help you in preventing infestations. Below, we’ve listed the common foods in factories and in homes that these pests usually infest:

Cereal products – moths and beetles
Stored grain – weevil, beetles and Angoumois grain moth
Nuts & Seeds – Indian meal moth and beetles
Dried fruits – moths and beetles
Cheese – beetles
Meat – beetles

3. What should you do when you find Stored Product Insects?

First, denying access to the foodstuffs should limit the infestation of pests in food. This can be done by having high hygiene standards on your premises and ensuring your facilities have adequate temperature control, especially in the summer months when high temperatures can expedite the development of stored insect pests as breeding cycles are shorter in warmer weather.

Temperature control: If possible maintain storage facilities at or below 16 C.
Ensure that high standards of hygiene, sanitation and housekeeping practices are maintained.
Clean up all excess food material such as spillages and dust accumulation in premises, machinery, equipment, storage and transport vehicles
All stock / food material should be stored off the floor and away from walls to facilitate cleaning and inspections.
Keep raw materials in robust packaging – sufficiently robust and or airtight packaging can prevent infestation in all food facilities

Once you have spotted an infestation it is advised that you discard and destroy all infested materials and ensure that you vacuum and clean the infested area, that is the best way to mitigate the problem.

I would advise that you call in professional pest control help. One that will reduce the probability of stored product pests entering the premises to provide regular inspections and monitoring control of the problem using approved pesticides to prevent and eliminate pests. Visit our page for more information.

All of this – combined with a robust hygiene and sanitation regiment – should help eliminate an infestation. Early detection will help save your business a lot of money and brand reputation.