In recent decades, there has been a notable decline in flying insect biomass levels. Since insects act as key contributors to various ecosystem services, it is important to understand changes in biomass levels for conservation purposes. Unfortunately, areas around the globe lack historical data on flying insect populations. This study attempts to establish a baseline estimate of insect biomass in Fairbanks, Alaska. Over the course of three summers (2020-2022), insect biomass was collected each week with four Malaise traps. From each catch, or weekly sample, a mass and DNA sample was obtained. There were no extreme declines in insect biomass over the three-year period, but variations in the average biomass of the highest catch (grams/day) were observed. The averages in biomass per catch from 2020 to 2022 were comparable to the biomass levels observed in Germany from 2000 to 2005. The results of this study imply that current Alaskan insect biomass levels may exceed biomass levels in other countries, which could be due to differences in the threats faced by insects at each site. Still, Alaskan flying insects could still be facing an overall decline in biomass. In order to fully assess the rate of decline, summer insect populations must be sampled for many years. Additionally, the DNA in the alcohol samples from each catch will be analyzed to determine if there have been any changes in species richness or evenness over the course of the study. These data will be compared to the variations in average biomass per week to determine if any correlations exist. Overall, this project sets a baseline from which future research can better explore potential declines in Alaskan flying insect populations.
Author(s): Hannah Bey, Biology and Environmental Science Major
Advisor(s): David Russell, Department of Biology
Matthew Valiga, Department of Biology
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