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Nanoscale delivery systems have the potential to improve the effectiveness of agrochemicals while reducing their negative environmental impacts. Herein, we explore the use of lignin nanoparticles (LNPs) to enhance the translocation of methoxyfenozide (MFZ), a non-systemic pesticide, in soybean plants under hydroponic conditions. LNPs (113.8 ± 3.5 nm and zeta potential – 53.3 ± 6.9 mV) were synthesized by emulsion evaporation from lignin-graft-poly(lactic-co-glycolic) acid and MFZ was incorporated into the LNPs (2.7% w/w). Twenty eight day old soybeans were grown hydroponically and were treated with 0.01, 0.1 or 1 mg/ml of LNPs. Plants were harvested after 6, 12, and 24 h of continuous hydroponic exposure to the roots and the concentration of MFZ was quantified in root, stem, and leaf tissues. The results suggest effective and time dependent transfer of MFZ from the hydroponic suspension to the roots, and translocation from the roots to the leaves. MFZ concentrations in the 1 mg/ml treated-plants at 24 h were 519.30, 3.72 and 1.72 μg/g in the roots, stem, and leaves, at 24 h, respectively, as compared to only 28.52, 0.58, 0.39 μg/g in the plants under neat MFZ exposure. The translocation efficiency (TE) of nanodelivered MFZ ranged from 0.06 to 0.08 at 0.01 mg/ml TE, 0.01–0.05 at 0.1 mg/ml, and 0.01–0.006 at 1 mg/ml over 24 h. Even though TE was higher for free MFZ, the concentration and total amount of analyte translocated to the shoots by LNPs were higher than those of free MFZ. In conclusion, LNPs were able to significantly enhance the translocation of non-systemic MFZ from the roots to the soybean aerial tissues in 24 h. This work provides a new platform to enhance the accuracy and precision of pesticide delivery and will be a valuable tool in sustainable nano-enabled agriculture.

A two-year study was conducted in Maine wild blueberry fields (Vaccinium angustifolium Aiton) on the health of migratory honey bee colonies in 2014 and 2015. In each year, three or five colonies were monitored at each of nine wild blueberry field locations during bloom (mid-May until mid-June). Colony health was measured by assessing colony strength during wild blueberry bloom. Potential factors that might affect colony health were queen failure or supersedure; pesticide residues on trapped pollen, wax comb, and bee bread; and parasites and pathogens. We found that Varroa mite and pesticide residues on trapped pollen were significant predictors of colony health measured as the rate of change in the amount of sealed brood during bloom. These two factors explained 71% of the variance in colony health over the two years. Pesticide exposure was different in each year as were pathogen prevalence and incidence. We detected high prevalence and abundance of two recently discovered pathogens and one recently discovered parasite, the trypanosome Lotmaria passim Schwartz, the Sinai virus, and the phorid fly, Apocephalus borealis Brues.

Pollinators, including honey bees, are responsible for the successful reproduction of more than 87% of flowering plant species: they are thus vital to ecosystem health and agricultural services world-wide. To investigate honey bee exposure to pesticides, 168 pollen samples and 142 wax comb samples were collected from colonies within six stationary apiaries in six U.S. states. These samples were analyzed for evidence of pesticides. Samples were taken bi-weekly when each colony was active. Each apiary included thirty colonies, of which five randomly chosen colonies in each apiary were sampled for pollen. The pollen samples were separately pooled by apiary. There were a total of 714 detections in the collected pollen and 1008 detections in collected wax. A total of 91 different compounds were detected: of these, 79 different pesticides and metabolites were observed in the pollen and 56 were observed in the wax. In all years, insecticides were detected more frequently than were fungicides or herbicides: one third of the detected pesticides were found only in pollen. The mean (standard deviation (SD)) number of detections per pooled pollen sample varied by location from 1.1 (1.1) to 8.7 (2.1). Ten different modes of action were found across all four years and nine additional modes of action occurred in only one year. If synergy in toxicological response is a function of simultaneous occurrence of multiple distinct modes of action, then a high frequency of potential synergies was found in pollen and wax-comb samples. Because only pooled pollen samples were obtained from each apiary, and these from only five colonies per apiary per year, more data are needed to adequately evaluate the differences in pesticide exposure risk to honey bees among colonies in the same apiary and by year and location.