Protecting pollinators from pesticides is crucial to a successful and prosperous pollination industry. Agrochemical use is necessary in modern cropping systems and required to maintain honey bee health. Understanding more about the correct use of these compounds and how to mitigate risks for pollinators is important for both beekeepers and fruit producers. This week we will look at one example product to gain further insight into label and product information to help understand associated risks and the precautions you should take.
What You Need to Know About Agrochemical Product Information
Health Canada’s Pest Management Regulatory Agency is responsible for pesticide regulation. Pesticides are stringently regulated in Canada to ensure they pose minimal risk to human health and the environment.
Manufactures are required to provide information on various aspects of their product. We will use Merivon®, a common fungicide for blueberry crops, as an example of the types of information a manufacturer must provide. This product may be used during blueberry bloom and therefore has potential considerations for honey bees and other pollinating insects.
Pesticides must be registered
for specific crops and uses. Merivon is registered for use on blueberry crops
to control Anthracnose, gray mold, Phomopsis Twig Blight, and Septoria Leaf Spot.
All products will receive a registration number, with our example Merivon, having
the registered number of 33951. They
will have a product name (Merivon Fungicide), and a registrant name (BASF
CANADA INC.). The manufacturer must provide all information on all active
ingredients. For Merivon the active ingredients are Pyrcolstrobin and
Fluxapyroxad.
Manufacturers must also provide a Safety Data Sheet (SDS) for their product. The SDS has numerous requirements, including hazard identification for human health and the environment. Merivon is classified as acute oral toxicity, acute inhalation toxicity, skin corrosion/irritation, reproductive toxicity, specific organ toxicity, and hazardous to the aquatic environment. The SDS includes information on First-Aid measures, fire fighting measures, accidental release measures, handling and storage, personal protection measures, physical and chemical properties, stability and reactivity, ecological information, disposal information, transport information, and regulatory information. Anyone using this product should familiarize themselves with the label instructions and the SDS.
The SDS also provides information on toxicology. The toxicological information provides specific values about the degree of toxicity for different routes of exposure. For example, the LD50 of Merivon for oral exposure to a female rat ranges between 50 and 300 mg/kg. For context, the LD50 of Arsenic for oral exposure to a rat is 763 mg/kg, which means it is relatively less toxic than Merivon in this comparison. The LD50 of Merivon for dermal exposure to a female rat is greater than 5000 mg/kg. The LC50 of Merivon for inhalation exposure to a female rat is 2.81 mg/L. The LD50 is calculated per kilogram of body weight and meant to only indicate comparable toxicity to other animals.
By way of further explanation, the median lethal dose (LD50) is the amount of a substance that kills 50% of the test population, usually modelled using rats. The lethal concentration (LC50) is the concentration of a chemical that kills 50% of the test population. These terms are often used interchangeably, but the LD is the lethal amount (or dose) of a solid substance, and the LC is the lethal concentration of a liquid substance. It is also important to understand that these measurements are time dependent. An LD50 or LC50 is determined within a certain time period (typically 4 hours since exposure). The LD50 or LC50 also differ depending on the method of exposure, whether it be topical, oral or inhalation exposure to the chemical. The values are determined through lab-based experiments, where a specific sample size is required for the experiment to have statistical significance.
According to use recommendations, Merivon has low toxicity to bees. Under a shared framework supported by PMRA, the US Environmental Protection Agency states that if the LD50 of the pesticide is greater than 11 micrograms per bee it is relatively nontoxic, and no bee caution statement is required on the label. Generally, fungicides are not considered to have toxic effects on bees but ongoing research suggests there is still uncertainty as to the real-world consequences of exposure to these pesticides (Rondeau and Raine, 2022).
When using pesticides there is a lot of important information on the labels that must be understood and followed so that the treatment is effective, but also so no harm is done to plants and animals, and their environment. In Canada, it is an offence under the Pest Control Products Act to use any product in a way that is inconsistent with the directions on the label. Pesticides can pose a threat to honey bees and other pollinators. Therefore, all precautions and directions on pesticide labels must be followed to avoid impacts of pesticides to bees.
We are excited to announce that more information about
protecting pollinators from pesticides with be available soon! To be published:
“PRACTICES TO PROTECT POLLINATORS FROM PESTICIDES – WILD BLUEBERRY”.
Connecting with ATTTA Specialists
Rondeau, S. and Raine, N.E., (2022) Fungicides and bees: a review of exposure and risk. Environment International, 165, p.107311.