Pollinators and Control Products: Using Science to Understand Bee Problems and Your Responsibilities


Mention bees to anyone in the green industry and there is immediate apprehension about taking a position on them. After all, who can argue that European Honey Bees are not a critical part of food crop pollination? However, what has been happening with bees over the last 10-20 years is the subject of much debate, a lot of emotion, and not enough science. Talk to some, and all our bees are dying, while yet others have heard about Colony Collapse Disorder (CCD), a poorly understood phenomenon. Yet others suggest that this concern is a lot of smoke but not much fire. So, what is really going on, what is causing these problems, and who if anyone is to blame?

A few years ago, I compiled information for a white paper about bee health across the world and learned, as with most things, that the facts are clearer, yet more complicated than any emotional slogan about saving bees. Bee populations need to be separated into managed and unmanaged hives, and for this discussion, I will refer to managed hives, for which we have a great deal more data. Managed hives are those which are used for pollination services and are moved throughout the country to pollinate specific food crops on a regular schedule. In fact, some 60-70% of all commercial hives are sent to California to pollinate the Almond crop before dispersing across the country to pollinate others.

Trucks carrying 400-500 hives subject bees to movement across thousands of miles, where they are exposed to heat and cold, suffer long periods of low nutrition, and interact with countless other hives, increasing the transference of bee pathogens. Dating back hundreds of years, there have been reports of unusual bee die-off across the US. In the 1940s, managed hive populations peaked before dropping back by the 1960s. This occurred long before any specific insecticides, which have been associated with their deaths, were on the market.

Today, most managed hives bee keepers, make more than half of their income from selling pollinations services, and not from honey production.


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The initial drop in bee populations related to the end of WW2. During the war, US citizens were encouraged to raise bees and use their honey as a substitute for sugar as sugar was being sent overseas for soldiers. When the war ended, bee hive populations dropped as citizens turned back to sugar as their main sweetener. In general, managed hive numbers are actually rising across the globe and have increased by 65% in the last 52 years (Source: FAO).

In 2007, a sudden onset of colony decline occurred in the US. This was defined as CCD. This disorder has not been observed in Europe. However, higher winter mortality of bees has occurred in managed hives for several years at levels higher than deemed acceptable, but without a link to CCD. To be clear, scientists make a clear distinction between winter bee decline and CCD, which they have not experienced since around 2007. While scientists do not fully understand the interaction between bee predators, pre-biotic factors, allelochemicals in the environment, and the impacts of farming practices, the USDA Bee Lab’s general assessment today is that CCD is due to a complex combination of factors rather than a single cause.

The Varroa Mite leads the list of bee parasites with significant or deleterious consequences to managed European Honey Bee hives. In countries where the Varroa Mite is absent, they’ve not experienced hive declines, despite using neonic insecticides, which are linked by some in the US to bee decline. Additional organisms attacking bees include tracheal Mites, Nosema fungus, Chalkbrood, and 10 distinct viral pathogens. According to the USDA Agriculture Research Service (ARS), a higher total load of pathogens, viruses, bacteria, and fungi was found consistently in only hives with CCD, and no single variable was found to be higher than others in those hives suffering from CCD. Interestingly, two insecticides commonly used for a variety of pests were found to be in significantly higher levels in non-CCD hives.

In countries across the world, vacuum seed planting machines caused the most significant and notable occurrences of bee poisoning by insecticides. This happened because seeds coated with insecticide were not properly managed and dust escaped into the air. Today, machinery has improved, coating technology enhanced, and seed coat technology has been limited in some countries.


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Red = Varroa Mite arrival; Green = imidacloprid first registered; Purple = CCD defined


In 1988, Varroa Mites were first introduced into the US bee population, reaching California in 1993. In 1994, imidacloprid was registered in the US. In 2006, CCD was first identified. Hive numbers dipped shortly after CCD was discovered but have since rebounded.

Current scientific opinion on pollinator decline origins include all the following: habitat loss, honey bee nutrition, climate change, pests, pathogens, agricultural insecticides, miticides, chemicals used intentionally to limit pests in hives, bee keeping practices, and a significant impact of migratory bee management pollination-services using interstate transportation.

There is a complex interaction between bees, plants, parasites, and diseases. These remain poorly understood. While there are over 10 bee viruses and several diseases, fungi, mites, and environmental factors impacting bee health, many scientists believe the practice of migratory bee pollination services weaken the colonies, and that, coupled with the persistent Varroa Mite problem, are the key factors in managed hive decline.

While the full details of my scientific review exceed the scope of a post such as this, and ongoing bee research continues to seek answers to the most effective ways to stabilize managed hives, there are things we can do today in each of our roles in the green industry.



When bees forage, it is important to have a diversity of food sources for optimal bee health. Conversely, monocultural fields offer reduced food choices and increased risk of nutritional challenges. Projects to restore wayside, roadside, old field, and community parks and garden with pollinator friendly wildflowers and native flowering trees are worth undertaking and partnering on. Arborjet is donating a portion of our sales towards habitat restoration while partnering with our customers.


Your Customers

Encourage them or assist them in planting pollinator friendly gardens and supplying water for bee access. Educate them on the facts around bee health and the distinction between managed hives and native bees. Native bees, including Mason Bees, are far more efficient pollinators than European Honey Bees. Consider offering them the choice to invite in native bee populations, which range into thousands of native species. Mason Bee hives are inexpensive, safe, and require little to no maintenance. Teach them about flowering plants for all seasons.



While you can’t assume your customers will be up to date with current research findings, your business depends on your knowledge. Visit websites like the USDA Bee Lab in Beltsville, Maryland, for their research, and an excellent independent site called Scientific Bee Keeping, where beekeepers discuss the newest strategies on fighting Varroa Mites and other hive challenges. Educate your employees, as we are only as safe as our least knowledgeable technician. Conduct pollinator safety training as a part of your safety training program.


Treatment Protocols

Be aware of the impact of your treatment methods, timing, and control products. Avoid flowering plants in bloom as they are directly at risk from contact sprays. Avoid cover sprays during windy conditions, which favor off target applications. Consider application methods that are less risk to foraging bees, such as sealed trunk injection, with the lowest doses and targeted applications. Did you know that many control products don’t move into flowers and fruits after injection, lowering risk to bees?

Understand the risks and advantages of the products you choose and opt for products which will be a lower risk to bees. Learn if studies have been conducted with these control products on the risk to bees. Be aware that some flowering plants and trees are not visited by bees, but are wind-pollinated, and understand how knowledge of pest life cycles can give you room to treat post-flowering on plants that are attractive to bees. Some of the more advanced trunk injected insecticides on the market, such as our TREE-äge, have been field studied for their risk to bees and have been found to pose lower risk than many older insecticides. For this product, the pollinator research was a prerequisite for EPA registration.

In an industry under close scrutiny for its environmental safety, your knowledge is truly power. It allows us to control our futures, protects the very essence of our business, and assures we can guard important and valuable plants from the ravages of both native pests and climate change. It also affords protection from invasive insects and diseases against which native trees lack any natural defenses.

To learn more about how to protect pollinators such as bees, connect with us today.