Bee Careful with Pesticides

Bee Careful with Pesticides - Dr. Eric Mussen 

Beekeeper complaints about the failure of their bees to emerge from the pupal stage, beginning 17 days after applications of the fungicide Pristine to almonds, prompted a three-year investigation into the cause.  Research showed that the fungicide, itself, harmed neither adult nor immature bees. The organosilicone adjuvant did not appear to be the problem, either, although a number of adjuvants can harm honey bees.

The unexpected discovery was that an insect growth regulator (IGR), diflubenzuron, had been added to the tank mix and applied with the fungicide at full bloom, apparently to assist in controlling peach twig borer.  This type of growth regulator inhibits the production of chitin, the basic structural compound of an insect exoskeleton.  Thus, the pupae could not develop into functional adults.

Insect growth regulators have been used on field and row crops, later in the season, with little harm to colonies.  However, later in the season, other pollens are likely being consumed, in addition to the IGR-contaminated pollen.  In the case of almonds, honey bees gather little else other than almond pollen, so they will be eating significant doses of whatever might be contaminating the pollen.  In this particular situation, it appears that too much IGR made its way into the larval diet and caused brood loss.  Usually, the addition of Bacillus thuringiensis (B.t.) to the tank mix would be a much more reasonable twig borer treatment from the standpoint of bee safety.


Despite the fact that no bee-toxicity warning may appear on the product label, or that the label might even state “safe for bees,” the testing behind those statements usually relates to studies conducted on acute toxicity to adult worker bees.  Obviously, adult bees are no longer producing chitin, so exposure to IGRs should not damage them.  It is the immature stages that require protection, and current regulatory protocol does not mandate testing for negative effects of active ingredients, formulated products, adjuvants, or other “inert ingredients” on immature honey bees.
Probably no pesticide is totally benign to a honey bee colony.  Pesticides are designed to kill (“-cides”).  The best way to protect honey bees from poisoning is to reduce or eliminate the amount of pesticides that are returned to the hive in forager bees’ pollen pellets.  Many early-season tree crops shed their pollen in the morning and the bees are likely to collect nearly all of it by early in the afternoon.


By checking for pollen loads on foraging bees on the bloom, an applicator can determine when the pollen foragers have basically finished foraging for the day.  At that time, pesticides that are not acutely toxic to honey bees can be applied to the crop.  Nectar foragers that still may be visiting the contaminated bloom do little to contaminate the pollen stores.  By avoiding contaminating pollen and pollen foragers, applicators can go a long way toward protecting the health of honey bee colonies.

Working With Monsanto?

I found this on the site. But I find this organization to be INDUSTRY oriented.Why the capitalization? It is because PAm is the group that is working with Monsanto. Yes, with Monsanto. They are huge owners of land and colonies that pollinate almonds,blueberries, cranberries, by trucking colonies around the states. Their motive is money, in my opinion, not the honeybee.

Howard F. Schwartz, Colorado State University,
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I, too, want to make a living with the honeybee but I am not looking to have 5000 hives that pollinate areas hundreds of miles away. This should be done with local talent. As it stands now just almond orchards require close to 2/3 of the total hive population of the US. Imagine if  that many kids were to be mingled in a giant arena and fed just hot dogs (almond pollen has a very low nutrient value for bees). Any parent in their right mind would know that this was a giant pool of sickness (mites, nosema, SHB,etc) just waiting to spread to the families of these kids when they go back home. Yet this is what happens every Spring in the almond orchards.
Not much here for forage. And add to that pesticides. This is not what a good parent does. The children would become sick and the family as well. If we sent them time and time again they would become chronically ill. Sound familiar?
Backyard beekeepers may be the saving grace in the fate of our honeybees.
Let's try to work for the bees a little bit since they have worked so hard for us.
Be careful with pesticides and better yet do not use them at all!