THE FORMULATION MAKES THE BEE POISON: CO-FORMULANTS AND POLLINATORS

We are presently focused on study of the role of pesticides and their co-formulants in honey bee and overall pollinator decline. Insufficient research has been done to extend beyond the readily available bee acute toxicity information for individual pesticide active ingredients into an assessment of the consequence of total chemical loads and exposures that incorporate co-formulants and adjuvants, and the resulting agrochemical interactions. Our recent work indicates that honey bees are unusually sensitive to common 'inert' ingredients used in agrochemical formulations and spray tank adjuvants. For the sustainability of honey bees, other pollinators and beneficial insects, it is vitally important that co-formulants be disclosed and their effects investigated. There is a new tendency to market pesticide blends containing multiple classes of insecticides or fungicides, or their mixed combinations without any further ecotoxicology testing. Many insecticide and fungicide combinations are utilized for seed treatments and in crop pest control that can result in hive residues that synergistically combine by themselves or with miticides used to control Varroa to poison honey bees. These blends usually require proprietary adjuvants to achieve high efficacy and broadly control many pests. The impact of these synergistic blends on non-targets including bees cannot be fully understood without knowing the identity of proprietary inerts and adequate testing on the appropriate species. The adjuvants themselves are largely assumed to be biologically inert and are therefore subject to minimal scrutiny and toxicological testing by regulatory agencies. Our results indicate that organosilicone surfactants are among the most toxic adjuvants, both sublethally and acutely, to adult honey bees. Honey bees are exposed to a wide array of pesticides as they conduct normal foraging operations, meaning that they are likely exposed to many spray adjuvants as well. These landmark studies should help demonstrate the need to disclose more information on inerts in agrochemicals, since it appears that 'the formulation and not just the dose makes the poison.' The impact of systemic pesticides, seed treatments, formulation additives, and other pesticides and their combinations on non-target species, and their role in honey bee and other pollinator health are of global consequence to food security and future crop protection strategies. We anticipate that if 'inerts' are influencing pesticide levels and general hive stress, formulation recommendations can be optimized for use in bee foraging areas.