University of Tennessee at Chattanooga
Place of Publication
Urbanization has been shown to create a rapid change in the environment as you move from rural areas to urban areas. It can create a multitude of effects on the environment. Some examples include, land disturbance, pollution, increasing temperatures and a disturbance in vegetation and biodiversity. Insects are useful organisms that provide maintenance and upkeep for ecosystem functioning. The rapid development of urbanization and how it is changing the environment may impact insect morphology. Measuring morphological change in organisms have been used successfully as indicators of environmental and ecological disturbance. Changes that take place in an insect’s morphology may indicate stress and environmental instability, which will help deepen the understanding of urbanizations impact on urban ecosystems. To evaluate the effect of urbanization on insect morphology, I conducted a meta-analysis of 23 published peer-reviewed studies focused on insect morphology within the context of urbanization. The resulting sample sizes and effect sizes given for changes in morphological traits were extracted and converted to effect size Pearson’s (r) for a more uniform measurement to analyze in the meta-analysis. I wanted to assess how urbanization impacted insect morphology and understand what may be the driving the effect of urbanization on insects. To identify possible sources of variation across studies, I analyzed five variables that focused on morphological traits, insect order, ecological level, environmental conditions and sex. The results indicated that although the overall effect size (r=0.19) of all studies included showed a change or significant effect in the morphological traits of insects between urban and non-urban areas, only ~25% of those studies had an actual impact. The majority, ~75% of studies did not show urbanization to have a significant impact on insect morphology. The insect orders, Hymenoptera, Hemiptera, Odonata and Orthoptera showed a significant effect in morphological changes. Studies that focused on body size and a combination of multiple morphological traits showed a significant effect in morphological changes. In terms of ecological organizations, both population and community groups studied had a significant effect on insect morphology. Disturbance and temperature were the only environmental conditions that showed a significant effect. Studies that measured changes in insect morphology with combined male and female populations showed a significant effect in morphological changes versus studies that focused on a singular sex. These findings may suggest urbanization is causing morphological changes in insects by some capacity but it is not as impactful as one would presume.
B. I. S.; An honors thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Bachelor of Integrated Studies.
21 unnumbered leavves
Bailey, Evann L., "The effects of urbanization on insect morphology: a meta-analysis" (2021). Honors Theses.