From Eric Mussen's Newsletter Neonicotinoids Under Review This spring the California Department of Pesticide Regulation (DPR) decided to request more information on the effects of the uses of the nitroguanidine class of neonicotinoids. Specifically, they wish to see information on imidacloprid, clothianidin, thiamethoxam, and dinotefuran. As you may know, imidacloprid is marketed by a very large number of companies. Since the original patent belonged to Bayer CropScience, their company will be presenting data to cover the other distributors. This review will cover 282 different pesticide products registered to 50 different registrants. The decision to request this review was based on an "adverse effects disclosure" pertaining to imidacloprid. There were twelve residue and two combination residue, honey and bumble bee studies of imidaclo- prid use on a number of ornamental plants. The two triggering items were "high levels of imidacloprid in leaves and blossoms of treated plants, and increases in residue levels over time." The bits of data that were coming in demonstrated that residues of imidacloprid in the blossoms of treated trees could exceed, in one case by twenty times, the LC 50 for a honey bee, which is estimated to be ? 185 ppb. An LC 50 is the lethal concen- tration that would be expected to kill 50 of 100 bees consuming that dose. The major concern relates to pollinator exposure, so the following uses were exempt from this examination: 1. gel or impregnated strips 2. termiticides 3. rodent flea control products (field) 4. pet spot applications 5. ant and cockroach baits 6. premise pest control 7. manufacturing use products. DPR hopes to obtain residue analyses on nectars and pollens of treated agricultural crops that require pollination. DPR also is going to require results from studies designed to determine the consequences of having residues in the diets of various stages of honey bee development. US EPA also has a review docket for imidacloprid under way. In an attempt to better ensure a "level playing field" for the neonicotinoid class as a whole, EPA will be looking at the rest of the neonicotinoids in fiscal year 2012. I have reviewed enough published information on neonicotinoids and honey bees to know that the findings are going to come in many shades of gray, not in black and white. *********************************************** The BEE-L mailing list is powered by L-Soft's renowned LISTSERV(R) list management software. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html Guidelines for posting to BEE-L can be found at: http://honeybeeworld.com/bee-l/guidelines.htm