Oxidative stress levels in two pollinators from three different landscapes

It is well known that different environments can lead to stress in pollinators. Two important pollinators in agriculture are honey bees (Apis mellifera) and small carpenter bees (Ceratina calcarata). Different landscapes: conventional, organic, roadside utilize different pesticides and management practices for pest control. The roadside landscape is a control for minimum application of herbicides and management. Oxidative stress (OX) is a state of imbalance between antioxidants and reactive oxygen species, which are the byproducts of oxidative phosphorylation in the mitochondria. It is unknown whether the differences in these landscapes affect the oxidative stress of pollinators. Conventional farms offer the most exposure to pesticides, which have been related to increased stress levels. We hypothesized that honey bees and small carpenter bees (SCB) from conventional farms would experience the highest levels of OX. Results from the Thio Barbituric Acid Reactive Substances assay indicated that honey bees and SCB of organic, conventional, and roadside landscapes experienced lowest to highest OX levels. While this is not representative of the presumed outcome, previous research has shown that feral bees have a tolerance to high stress levels. The same could be true of honey bees and SCB from roadside landscapes, where the conditions imitate natural habitats. Organic farms use naturally derived pesticides and moderate management practices, likely contributing to their lower levels. Examining how these pollinators are affected by farm landscapes can reveal the benefits and detriments of each management practice. This will hopefully lead to practices that are healthier for pollinators.