Uncovering the Secrets of Colorado Grasshoppers: How Climate Change is Shaping Insect Populations

The study of insect populations, particularly grasshoppers, in Colorado has shed light on how these creatures are responding to a warming world. The research, published in the journal PLOS Biology on Jan. 30, reveals that some grasshopper species have actually increased in size over the past 65 years, despite concerns about a decrease in insect populations worldwide.

The study was made possible by the fortuitous discovery of a collection of 13,000 grasshoppers gathered between 1958 and 1960 by entomologist Gordon Alexander of CU Boulder. After his untimely death in 1973, the collection was rescued by his son and eventually donated to the CU Museum. In 2005, César Nufio, a postdoctoral fellow, rediscovered the collection and initiated a resurvey of the same sites to collect more grasshoppers.

The researchers, including Nufio and colleagues from UC Berkeley and the University of Washington, found that the impact of climate change on grasshopper sizes varied depending on the species and their life cycles. Species that overwinter as juveniles and can take advantage of an earlier spring to feed on greenery increased in size, while species that hatch in the spring from fall-laid eggs decreased in size due to vegetation drying up earlier.

The findings highlight the complexity of species responses to climate change and emphasize the importance of considering ecological and environmental contexts. The researchers were able to make predictions based on the grasshoppers’ life cycles and environmental conditions at the site, demonstrating the value of long-term studies using museum collections.

The study also revealed that grasshoppers at lower elevations increased in size, while those at higher elevations did not, likely due to differences in food supply and temperature changes. The researchers are continuing their collaboration to understand the underlying metabolic, biochemical, and genetic changes that drive these size changes.

Overall, the study provides valuable insights into how grasshoppers are adapting to a warming world and underscores the importance of considering biological principles in predicting climate change responses. The research was supported by the National Science Foundation and involved a team of researchers from multiple institutions.