Insect Identification in Food Plants

What is the first thing you do when you notice an insect in your food plant? Do you panic and call your pest control service provider? Do you immediately start thinking about which insecticides are safe for use in a food facility? What would happen if you actually knew how to identify the source of your insect issues based on the behavior of the perpetrator?

Basic knowledge about insect identification, biology and behavior has become hard to find in most food plants. Most food plants are quick to place all responsibility for pest issues on their contracted pest control providers. Surprisingly though, most of these technicians are not equipped with this knowledge either! Because of this, developing pest problems are often not realized until they are in the disaster stage where they cannot be overlooked. This trend needs to be reversed. Instead of focusing so much energy on eliminating the insect, resources should be spent investigating the reason they are present. After all, you can exterminate thousands of insects, yet still not solve the source of the problem.

Think of insects found in your food plant as messengers. Each species has a story to tell. They have been places and seen things that we are not aware of. They are proof that some aspects of our programs are not meeting the needs. Though they may be small, many food plant insects are moving billboards of information.

Psocid Scenario
The psocids along the base of the wall in the production area can tell you many things about your own self-inspection program. There may be an accumulation of old moldy product behind the I-beam because that area is not checked after cleaning and the inspection crew has missed it for months. The seal at the base of the wall could be compromised allowing water to wick up behind the wall covering and encourage mold growth. The miniature insect trails on the outside of the mixer are not flour beetles, but psocids living under the seal in the molded flour!

Flat Grain Beetle Scenario
Those little insects you have been seeing in greater numbers in your sifter tailings that look small enough to get through your sifter screens are likely doing just that. They have pretty long antennae for such a small bug. When you identify this little insect, you will likely find it to be a flat grain beetle. It feeds on mold on out of condition grain. But is it your problem or can you blame the mill? You will not know until you first check your system. Passing the blame to the mill can be challenging because these insects live in the environment around your facility.

They are excellent flyers, small enough to get past the smallest openings. Getting to a mold issue on a silo or a rooftop is not a problem for them. Imagine how much mold would accumulate from a breather bag that has leaked flour onto a pitch-and-gravel roof for a long period of time. When rain wets the flour, it creates the perfect storm for mold growth inviting flat grain beetles to a feast. Imagine how many tens of thousands of these insects make this area home before the issue is discovered. This is not just a pest control issue. You are now going to have to replace this section of roof to satisfactorily solve this problem.

Fruit Fly Scenario
A facility recently battled a fruit fly problem in a production area that also tested positive for Listeria. They assumed that the floor drains were the source of the problem. However, this was not the case. Fruit flies tend to breed in cracks and crevices either in the immediate affected area or a distance away. An inspection of the area along the wall revealed that concrete was installed at some point over the race-car curving to create more of an angled floor-wall junction. The material had come loose and removal of a few pieces revealed fruit fly maggots and decomposing organic material. Swabbing and culture of this material tested positive for Listeria. In this case, understanding the behavior of the fruit fly led to the source of both problems. No amount of sanitizer in the floor drains was going to eliminate the fruit fly issue or the Listeria results.

Cigarette Beetle Scenario
Of course, there are occasional situations where all research goes out the window because a species decides to make you stand up and pay attention! They may invade a location and product so unrelated to what we expect that we discount everything around us because it just should not be. A recent case of cigarette beetles in a cheese production facility is a classic example. Everything you know about this insect says they wouldn’t be attracted to cheese products. You search for months, you trap for months, and every pest expert you talk with also says no. Then, the light bulb turns on when you realize you are stomping your feet on the very source of the problem. What you thought was the floor is actually a buildup of old product riddled with cigarette beetles feeding on the desiccated cheese.

Though this was the exception to the rule, the search persisted until every option had been eliminated. Using the confirmed information allowed the investigators to recognize a difference and pursue it. Situations like this lead to a better understanding of the capabilities of these insects.

Each of these scenarios represents a failure or weakness in the prerequisite programs that were designed to prevent these events, but were not carried out properly. Understanding the insects helped identify the deficiencies and provide a more effective and permanent solution to the problems.

Today, more than ever, the proper role of insecticides in controlling food plant insects is defined. There is a time and a place where pesticides can contribute to a solution. Unfortunately, too many people continue to think of pesticides as the only solution to their pest issues and repeatedly fail to truly resolve an issue, thus continuing to put food products at risk. If the individuals applying these pesticides do not understand the insects’ behavior, how do they possibly know what material to use and where to place it to have the most impact?

There is unlimited online information from credible sources about food plant insects. There are publications and references to help identify insects and determine effective treatment approaches. Researchers have learned so much about the biology and behavior of important pests over the past few years. It would be ridiculous to expect every person responsible for managing a food plant’s Integrated Pest Management (IPM) program to obtain a degree in entomology. However, it is realistic to expect anyone responsible for these programs to acquire basic knowledge and be functional in their role. Timely and appropriate response to a pest issue is not only cost-effective, it just makes sense. Why would you fumigate the entire facility when one ground beetle wandered in, when all you need to do is pick it up with paper towel, crush it, and properly dispose of it, then look outside for a source?! Knowledge and understanding allow you to recognize an issue for exactly what it is.

The author is Head of Food Safety Education, AIB International.