Agrochemical occurrence on colocated wildflowers and wild bees collected near beef cattle feed yards and row crops

Abstract

It is well established that agrochemicals can pose significant threats to native pollinators; however, relatively little is known about pollinator risks associated with agrochemicals that are used on beef cattle feed yards. Recently, feed yard-derived agrochemicals and those from row crop agriculture were quantified on wildflowers growing on the High Plains, USA. To better characterize pollinator risks on the High Plains, we collected colocated wildflowers and foraging bees across three field seasons for analytical determination of residual agrochemicals. Agrochemicals were detected and quantified on the majority of wildflowers (85%) and nearly half of bees (49%). Permethrin was the most frequently detected analyte on wildflowers (32%) and bees (17%). Flower hazard quotients and flower hazard indices were calculated to deterministically evaluate risk to foraging pollinators. Mean flower hazard quotients exceeded one for 5/16 analytes (31%), and flower hazard quotients calculated for 30% of wildflowers were greater than 50. Flower hazard quotients for clothianidin exceeded 400 for 14% of wildflowers, which portends conditions conducive to frequent bee mortalities. Flower hazard indices were greater on wildflowers from mid-July to mid-September as compared with wildflowers collected earlier in the summer, which coincides with row crop planting and increased prevalence of feed yard flies. Hazard quotients and hazard index values calculated from agrochemical residue data suggest that pollinators frequenting wildflowers near beef cattle feed yards and row crops on the High Plains are at risk from both individual sources, and more so when considered in combination.

Bee Pollinator Mortality Due to Pesticide-Laden Particulate Matter from Beef Cattle Feedyards

“…Recently, this contaminated PM has been detected up to 12 km downwind of feedyards . Further, a variety of pesticides and parasiticides have been detected on wildflowers, wild pollinators, and in nesting matrices of wild bees and wasps occurring near beef cattle feedyards in the Texas Panhandle, USA.…”

Laboratory Determination of Particulate‐Matter–Bound Agrochemical Toxicity among Honeybees, Mason Bees, and Painted Lady Butterflies

“…The PM used in each exposure experiment was subjected to the agrochemical extraction methods described by Peterson et al (2020); Peterson et al (2021b) to verify concentrations. Similarly, agrochemicals were extracted from tissues of pollinators used in exposures via methods described by Peterson et al (2021b) to determine agrochemical residues in exposed pollinators.…”

“…The PM used in each exposure experiment was subjected to the agrochemical extraction methods described by Peterson et al (2020); Peterson et al (2021b) to verify concentrations. Similarly, agrochemicals were extracted from tissues of pollinators used in exposures via methods described by Peterson et al (2021b) to determine agrochemical residues in exposed pollinators. Briefly, a known mass of fortified PM, or a known mass of exposed pollinators (individuals from a single replicate were pooled and instrument readings were divided by the number of pooled individuals to obtain a ng/individual concentration), was placed into a 15-mL centrifuge tube, homogenized, and spiked with the internal standard tris(1-chloro-2propyl)phosphate before addition of 1:2 water:acetonitrile (v:v), followed by vortexing.…”

“…Recent studies indicate a potential for pollinator exposure to agrochemicals via fugitive beef cattle PM (Peterson et al, 2020;Peterson et al, 2021b). Particulate matter is a mixture of solid and liquid particles suspended in air (US Environmental Protection Agency [USEPA], 2022) and can serve as a carrier of toxic agrochemicals (see Forero et al, 2017;Lentola et al, 2020).…”

Atmospheric transport of particulate matter and particulate-bound agrochemicals from beef cattle feedlots: human health implications for downwind agricultural communities

“…In addition to loose soil, pen floor material contains a complex mixture of chemical and biological contaminants, including veterinary pharmaceuticals metabolized and excreted via feces and urine (Aust et al, 2008; Blackwell et al, 2014; Blackwell, Johnson, et al, 2015; Blackwell, Wooten, et al, 2015; Zhao et al, 2010), viral and bacterial pathogens (Alexander et al, 2011; Gaudino et al, 2022; Mosier, 2015; Qian et al, 2018), and pesticides (Modernel et al, 2013; Sadler et al, 2005; Yates et al, 2011). While it is well-documented that these facilities are detrimental to watersheds through off-site runoff of manure (Bicudo & Goyal, 2003; Sahoo et al, 2016), mounting evidence in the last two decades also implicates aerial dispersion of PM as a major transport pathway of agrochemicals beyond feedlot boundaries (Emert et al, 2023; McEachran et al, 2015; Peterson et al, 2017, 2020, 2021, 2022; Sandoz et al, 2018; Wooten et al, 2018). This is particularly problematic in arid and semi-arid regions, where dry pen floor material is aerosolized by cattle movement-driven mechanical disturbance (de Oro et al, 2021), which is then wind-transported downwind.…”