Stored Product Pests

A Look at the More Common Stored Product Pests in Perth, Western Australia

The battle against home pest infestations is typically perceived to be one between homeowners and various insects, rodents, and animals that infiltrate the home and make life miserable and even unsafe for a house’s occupants. While those are all common pests about which every homeowner should be concerned, those are by no means the only types of infestations that can threaten home, hearth, and lifestyle. Even our food stores are vulnerable to pest infestations. In fact, stored product pests have plagued mankind throughout its history. In fact, these pests are engaged in a continuous war on our food supplies, infesting them from the field to the pantry.

How bad is the problem?

The issue of pest-infested food stores is one that continues to plague human beings in virtually every area of the globe. Insects are remarkably adaptable creatures wherever the happen to live, and they have a natural drive to seek out food sources. They also happen to be extremely efficient at locating those food resources. Unfortunately, human habitats offer these creatures everything they need to survive and flourish, while also providing abundant sources of gran and other foods that can sustain pest populations indefinitely.

The fact is that these pests are attracted to many of the same things humans value: grains, nuts, seeds, cereals, and stores of dried foot can all be attractive nesting and feeding grounds for a wide variety of insect pests. Once a population takes up residence in any food supply, it will both consume and contaminate the product, causing economic loss and health hazards for anyone who comes into contact with the food.

While homes are common targets for these pests, houses are by no means their only option for obtaining the basic supplies they need to survive. Indeed, there are many businesses that are at special risk for stored product pest infestations – especially those companies and industries directly involved in the food supply. For example, food production facilities, and grain silos are common areas of concern. In addition, restaurants, farms, and bakeries are at also at risk. Even warehouses and stores that represent the final stages of the food production chain can experience these kinds of pest problems.

How much harm can a few insects cause anyway?

It is important to not underestimate just how bad a food store pest can be. Though these insects are miniscule in size, their impact on businesses, machines, and homes can be truly devastating.

  • An infestation in any store of foodstuff can result in contamination which can make the food unfit for human consumption. In a home, that can sometimes cause temporary financial discomfort as stores of grain, cereals, and other needed food have to be thrown out and replaced. In a business, that can translate into long-term disruption due to loss of stock and sizeable costs required for product replacement.
  • Even when insects don’t directly contaminate foodstuffs, their continued presence can cause warming that can produce excess moisture and higher temperatures – the precise conditions needed for the growth of various kinds of mold. The end result is no different than if the insects simply poisoned the food; it ends up being contaminated.
  • Insect activity can result in an increase in food caking inside of machines. Over time, that can result in less productivity, and eventually cause breakdowns as the machines end up being damaged.
  • Infestations are violating of regulatory codes, due to the danger they pose to public health. Even a small infestation can result in negative press, poor word of mouth, and the type of damage to a company’s reputation that can quickly spark a drop in income.

How to Know When You Have a Problem

Obviously, most people don’t spend an inordinate amount of time examining their food stores. The average farmer, for example, doesn’t exactly crawl into his grain silo with a magnifying glass to see whether there are insects within the structure. In most instances, infestations are fairly well advanced before the average homeowner or company even has a clue that something is amiss. At that point, there are some clear signs that can indicate a problem:

  • Grain and other foods may appear damaged from a structural standpoint.
  • Silk webbing from pupae may appear on shelves or even on the outside of food storage bags, usually right near a hole or other entry point.
  • Larvae may be found lying around the area.
  • In some instances, you may catch site of adult insects moving about. Obviously, seeing either larvae or adult insects in the area is a sure sign that you have a bug problem.

Recognizing the Common Pests

There are many common pests of this kind. Knowing which one you’re dealing with can be a great first step toward resolving your infestation problem.

  1. Pantry Moth. This moth is often referred to by more specific species names, since just about any moth found in the kitchen can be viewed as a pantry moth. As a rule, however, there are two kinds of moth that accurately deserve the appellation: The Indian Meal Moth and the Mediterranean Flour Moth. Pantry moths, like most insects, have the standard egg, larvae, pupa, and adult life cycle.

Pantry moths are a persistent pest that can quickly infest your food stores and contaminate your pantry. Their life cycle is a rapid one, which means that you can go from a few moth pests to a horde of invaders in a relatively short period of time. Their larvae will easily locate any accessible food source and then devour it, working their way through their life cycle so that their offspring can start the process all over again.

  1. The Rice Weevil. This pest is responsible for tremendous grain loss each year, as it infests grain stores around the world. They bore into and live within grain, and have a rapid life cycle that enables their populations to reach infestation rates before most people ever realize that they’re there. Because they can fly and reach just about any source of grain that isn’t completely sealed off, this species of insect is considered by many to be a major to the grain supply.
  2. Broadhorned Flour Beetle. The broadhorned beetle has two large mandibles on its head that give it its name. These insects thrive in warm climates, and prefer foods like flour and dough – which makes them a threat to restaurants, bakeries, and homes alike. They often supplement their diets with the eggs and larvae of any moths they run across.
  3. Cheese Mites. Only half a millimeter in size, the tiny white cheese mite has a taste for dairy products. While it will consumer dried eggs and fruit, and even flour, its main source of food is cheese of any age. Unfortunately, you don’t want to share your food with this pest. It contaminates any food source it interacts with, and that can lead to intestinal discomfort or skin irritations for humans who eat after them.
  4. Coffee Bean weevil. Growing as large as 4 millimeters in length, the Coffee Bean weevil is a flying insect that prefers corn and coffee beans as its main food sources. They also tend to infest dried fruit stores, nutmeg, and similar food types. The name is derived from the weevil larvae habit of boring themselves into coffee beans, and using those beans as habitats for their pupation stage.
  5. Confused Flour Beetle. The confused flour beetle is by no means confused. That name was given to it by humans who weren’t initially sure about what type of insect it was. The reality is that this creature knows exactly what it wants, and it knows how to get it: flour, grain, and other dried foods. The species lacks the ability to feed on whole grains, but they are adept at locating damaged kernels.

The breeding rate of the confused flour beetle poses a particular concern, since the females actually lay upwards of 500 eggs at one time – each of which can live to be more than three years old. Those eggs are laid in flour or along the outside of the food container, hatch in less than a week, and soon after start their burrowing activity.

  1. Drug Store Beetle. Sometimes called the Biscuit Beetle, this insect has an insatiable appetite for almost any type of dried food product – including a variety of grains, seeds, plants, and spices. Though it is not considered to be a major infestation menace where grain stores are concerned, it is a serious pantry pest that will chew up not only foodstuffs but books, leather, and wool. They are only 3 mm long, and leave tiny holes in materials close to their infestation area. They are fairly prolific breeders, with females depositing as many as 100 eggs at a time. Unlike some of the other pantry pests, however, they have a fairly short lifespan – usually no more than four weeks.
  2. Flat Grain Beetle. This flat-bodied beetle is a glutton when it comes to cereals, dried fruits, and similar stored foodstuffs. It is among the smallest of insect pests, but makes up for its diminutive size with a dynamic lifecycle that sees newly deposited eggs complete the entire maturity process in as little as five weeks. It prefers warm and moist environments, so it is rarely found in areas where foodstuffs are kept dry, cool, and well-sealed.
  3. Grain Mite. This tiny insect has four pairs of legs and a pale body in its adult stage. As its name suggests, it is attracted to grain and flour – but will also avidly consumer any cheese, yeast, mold spores, and similar foodstuffs. It is often found in areas where the moisture content is high and fungal growth is abundant.
  4. When an infestation occurs, it is sometimes possible to detect the insects’ presence from the telltale brown dust they leave in their wake. Once they infest grain, they attack the germ of the kernel. Larger infestations increase moisture content and create a foul odor in the food. Finally, it is worth noting that many humans are allergic to mites, so coming into contact with contaminated foodstuffs could create the right conditions for an allergic reaction.
  5. Granary Weevil. The granary weevil is among the most common of stored product pests. It is found in most places around the world, and has been known to both diminish crop yields and destroy harvested grains. Females deposit eggs in grain kernels, and those weevils begin their life cycle from within the grain. One of the reasons why this pest is such a menace to human food sources is the incredible number of offspring they produce each year. Just one pair of weevils can, over the course of a year’s time, create as many as 6,000 additional pests.

This is a contamination pest, and entire grain stores often have to be destroyed once a granary weevil infestation takes place. Wheat, rice, corn, oats, and other grain crops are all vulnerable to this voracious menace. Because of the cost involved in destroying a grain harvest, most efforts to control this pest focus on prevention.

  1. Lesser Grain Beetle. This beetle is commonly found in stores and warehouse operations, particularly animal feed outlets and nutrition centers that deal with organic foodstuffs. It is also a common menace to stored supplies of both corn and wheat. In addition to those food stores, the Lesser Grain Beetle will also attach supplies of cocoa beans, peanuts, dried meat, fish, nuts, and even tobacco.

Prevention is The Best Approach

Given the incredible amount of damage that any of these pests can do to food stores, it is wise to do everything possible to avoid an infestation in the first place. Even a seemingly minor infestation can result in contamination that renders the entirety of that food supply unusable for human consumption. While no prevention techniques are 100% effective every time, the good news is that there are measures that businesses and homeowners can take to reduce the likelihood of these types of pest problems.

  • Focus on cleanliness. Spilled foodstuffs, dust, and other clutter in and around the home, warehouses, farms, and businesses can attract these pests and provide them with the ideal environment to begin their incursion.
  • Work to properly seal foodstuffs wherever possible. Airtight packaging is always preferred.
  • Make sure that your premises are sealed using proper insect screens, and that you take care to properly maintain those seals to prevent any invasion.
  • Control the air temperature to ensure cooler temps rather than the hot, humid conditions most of these insects prefer.
  • Keep food elevated and away from ground level or low-lying shelves. Also make sure that there is some distance between the shelves and any walls, to prevent easy access.

Remain observant and Vigilant at all times

Remember that most infestations begin in a limited area of the home or facility – often with but a single bag of flour or a single pallet of food. Once established, however, any insect invaders will quickly disperse to other food sources.

  • Inspect any foods you are bringing into your premises, and do so in an area separate from your food storage area. If active pests or evidence of infestation are discovered, remove the foods from your building immediately.
  • Use light traps to monitor and control flying pests. That can help to give you an early warning of the presence of many major pests, so that you can proactively deal with any threats.
  • Have professional pest control services install monitoring devices and traps that use insect pheromones to lure pests and capture them. These measures can help in the vigilance process, and provide critical information your pest control specialist will need to rid your building and food stores of any invasive species.

Rely on Professionals

**Please Note** – Rockypest does limited servicing on stored products pests. This page is for Information purposes.

Professional pest control technicians can help to identify and isolate specific pest threats in any environment. Their main goal in these instances will be to protect your food stores and ensure that product contamination is limited as much as humanly possible. To achieve those goals, they have a variety of options at their disposal:


Pesticide spraying can be done in a variety of ways, depending upon the precise situation involved. There are auto-aerosol devices that release timed dispersals of pesticide, space spraying techniques for localized infestations, and even more localized spraying done with a targeted approach focused on cracks and crevices. The latter is often best used as a preventive measure prior to any infestation beginning.


Dusting is similar to the use of pesticide sprays, but utilizes dry dust rather than liquid pest killers.


This process releases toxic gases that will destroy insects at every stage of development. While effective, fumigation does require an enclosed environment to accomplish its mission. The gas needs time to work, so anything that might disperse it prematurely will result in failure.


Though not always practical in every situation, some raw materials can be saved from infestation by subjecting the entire store to hear in excess of 60 degrees for half an hour. That effectively kills everything from egg to adult.

Treating Grain and Bins

There are also methods that can be used to treat grain prior to infestation. These systems require that certain insecticide dusts be applied to grain when it is brought into the facility. Because all insecticides are considered toxic, this process is typically only used when foodstuffs will be stored for lengthy periods of time. As that grain is later transported and stored elsewhere, the toxins in the insecticide gradually dilute so that the food can be safely processed for human consumption.

Insect pests can be devastating to human food stores, and have been a constant threat to mankind throughout human history. Despite massive improvements in food production and pest prevention techniques, infestations still occur with alarming regularity. Fortunately, a competent pest control expert can help you to quickly regain control of your building when insects attack your food storage areas. To protect your premises and your livelihood against these invaders, always focus on essential prevention measures first. If those techniques fail to keep these pests at bay, contact the best pest control experts in Perth to help you deal with your infestation problem.