Larval Development Rate of Montane Leaf Beetles

Species at high elevations can be indicators of climate change. Willow leaf beetles, Chrysomela aeneicollis, live in mountains in Eastern California in diapause under snow cover most of the year. Beetle populations tend to decline and retreat to higher elevations after dry winters. Many study populations became extirpated after the drought of 2012-2016. Allele frequencies at the metabolic enzyme locus phosphoglucose isomerase (PGI) vary greatly along a latitudinal gradient. A single non-synonymous single nucleotide polymorphism at PGI is responsible for this latitudinal variation and it has been shown to influence metabolic rate and the stress response. We surveyed beetle populations in the summers of 2011 and 2012. We also analyzed temperature data. Larval development proceeded more rapidly in populations with a higher frequency of the northern PGI allele. Our results support the hypothesis that environmental and genetic factors influence survival and performance in nature.