E.P.A. should ban the use of thiamethoxam, not expand it

Soya Plantation in the AmazonPlantação de soja na Amazônia
Photo: Bruno Kelly, Greenpeace

Editorial by MATT KELLY

Yesterday was the last day for public comment on the petition to expand the use of thiamethoxam (a neonicotinoid insecticide) now being considered by the Environmental Protection Agency. Based on the amount of research showing the harmful effects of neonics on bees, as well as the E.P.A.’s extremely limited bee risk assessment, the E.P.A. has no basis upon which to approve the application to extend the use of thiamethoxam. Quite the opposite: the available evidence makes clear that we need to impose greater limits on the use of thiamethoxam and other neonics, and that the E.P.A. should support a full ban of these products in the United States.

Here are the comments and supporting evidence that I submitted to the E.P.A.:

Do not approve the extended use of thiamethoxam as a foliar spray as requested by Syngenta.

The harmful impact of neonicotinoid insecticides (including thiamethoxam) on bees is well documented. Even at sublethal exposures, neonics can damage a bee’s ability to communicate, smell, navigate, reproduce and simply move its body; it can disrupt the health and longevity of a colony of social bees. (See references below.)

While the EPA’s “Preliminary Bee Risk Assessment to Support the Registration Review of Clothianidin and Thiamethoxam” released in January of this year suggests that using thiamethoxam as a foliar spray for the crops specifically listed in the application poses little in-field risk to bees, there is a huge fault with the assessment: it predominantly considered and only assessed the impact on honey bees. Which means the assessment failed to consider the nearly 4,000 other species of bees that exist in North America. The authors of the assessment fully acknowledge this and they clearly state that limited conclusions can be drawn (page 344):

“…there is uncertainty regarding the extent to which any risk assessment process that relies on data on a specific species (e.g., A. mellifera) can be considered representative of an entire taxon or multiple taxa. This is especially true for honey bees, which are a highly social (eusocial) species, where the colony/hive is dependent on the collective tasks of multiple castes and function as a “superorganism”; whereas, the majority of other bee species, particularly those species native to North America, are solitary.”

This narrow focus is particularly concerning when considering the crops mentioned in Syngenta’s application. Take potatoes for example. A 2017 study of commercial potatoes in Michigan found 58 differ species of bees present in and around the fields – Apis mellifera was only one of these species. The overwhelming majority of bees in these fields are nothing like honey bees: they are solitary and ground-nesting, living completely different lives – and being impacted by thiamethoxam in completely different ways and to different extremes.

A main reason the EPA assessment concludes that thiamethoxam will pose a low risk to bees in potato fields is the presumption that potatoes do not produce nectar or pollen that is attractive to bees. This may be true for Apis mellifera, but bumble bees are main pollinators of Solanum plants in North America. The Michigan study specifically found that Bombus impatiens (the common eastern bumble bee) visited the potato flowers. Furthermore, the most abundant type of bee found in the Michigan fields was the sweat bee (Lasioglossum spp.); it is known to visit plants in the Solanum family (i.e. potatoes) to scavenge for pollen accessible from the flower surface.

Due to the significant body of research demonstrating the harmful impacts of neonicotinoids on bees as individuals and as colonies, as well as the EPA’s extremely limited bee risk assessment, the EPA has no basis upon which to approve Syngenta’s application to extend the use of thiamethoxam as a foliar spray. Quite the opposite: the available evidence makes clear that we need to impose greater limits on the use of thiamethoxam and other neonics, and that the EPA should support a full ban of these products in the United States.

References:
A. Buchanan, J. Gibbs, L. Komondy, Z. Szendrei (2017). Bee Community of Commercial Potato Fields in Michigan and Bombus impatiens Visitation to Neonicotinoid-Treated Potato Plants. http://www.mdpi.com/2075-4450/8/1/30

E. A. D. Mitchell, B. Mulhauser, M. Mulot, A. Mutabazi, G. Glauser, A. Aebi (2017). A worldwide survey of neonicotinoids in honey. Table S8 provides an extensive list of studies showing detrimental impacts associated specifically with thiamethoxam and other neonics on honey, bumble and solitary bees (Supplemental Materials, Tables S1-S9). http://science.sciencemag.org/content/suppl/2017/10/04/358.6359.109.DC1

This year the E.P.A. will be reviewing the registration of clothianidin, dinotefuran, imidacloprid and thiamethoxam for use as insecticides in this country. In theory, this is an opportunity to withdraw registration of these products and end their use. However, Scott Pruitt’s E.P.A. rejected a ban on chlorpyrifos in March and has repeatedly demonstrated a willingness to be guided by industry rather than its essential mission “to protect human health and the environment”; Pruitt’s E.P.A. seems more than inclined to ignore the evidence for harm and keep these neonics registered for use. All the more reason to speak out and make your voice heard. Public comment on the registration review of these four neonics closes February 20, 2018.