Meeting Abstract
P1.133 Friday, Jan. 4 Effects of environmental and genetic variation on survival and development of a montane insect in the presence of natural enemies ROBERTS, K.T.*; HEIDL, S.J.; DAHLHOFF, E.P.; SMILEY, J.T.; RANK, N.E.; Sonoma State University; Sonoma State University; Santa Clara University; White Mountain Research Center; Sonoma State University roberkev@sonoma.edu
Natural populations are confronted with unpredictable abiotic challenges and natural enemies, but interactions between genes, temperature and predation are poorly understood. Sierra Nevada populations of the leaf beetle Chrysomela aeneicollis distributed along latitudinal and elevation gradients are polymorphic at the glycolytic enzyme locus phosphoglucose isomerase (pgi) and mitochondrial gene cytochrome oxidase II (COII); latitudinal variation at pgi and COII are concordant. Prior studies have shown that effects of temperature on larval survival, development and locomotion differ among pgi genotypes; the most important enemies are specialist predators. Here, we relate genetic and environmental variation to larval survival and development in the presence and absence of natural enemies. Adult beetles were collected from genetically and environmentally intermediate localities and transplanted to high, mid and low elevation sites in three drainages to produce offspring there. Offspring were either exposed to predation or enemies were excluded. Survival and development of offspring was recorded from oviposition to pupation. Development rate was faster at warmer, low elevation sites but natural enemy pressure was lower at high elevation. Maternal pgi and COII genotype jointly affected development rate and survival of offspring in the presence of enemies. Predation was higher at low elevation and mortality was higher at high elevation in the enemy exclusion treatment. Genotypes from southern populations tended to develop faster and survive better than those from northern populations. We discuss these findings in relation to earlier studies of the adaptive significance of pgi.
