In the academic year 2009-10, we have developed markers of genetic variation that help us reconstruct the history of colonization, population establishment, and extinction in the high Sierra drainages where C. aeneicollis occurs. Past studies have revealed significant genetic differences among populations in different drainages, and among populations within a drainage. Most of our prior work focused on allozyme markers (i.e. polymorphic enzymes), and the PGI enzyme locus shows variation that correlates with environmental conditions in nature, while four other enzymes appear to vary neutrally irrespective of environment. Recently, we found that populations that differ strongly at the putative adaptive marker PGI also show significant differences in frequency haplotypes at mitochondrial DNA loci. Because the mitochondrial locus covaries with PGI we are currently investigating new markers to determine whether this pattern is general and reflects population history, or alternatively is under natural selection.
In Summer 2009, team beetle assembled at the WMRS Owens Valley Labs, and completed the season's genetics sampling (collecting adult beetles). They also completed the spring and fall beetle counts, and downloaded and re-launched the CUP in-canopy temperature loggers at 45 sites in the study drainages. The cups, in continuous use since summer 2000, shield the loggers from direct sunlight but are open to re-radiation from the ground. The team also deployed 40 new HOBO-PRO temperature/humidity loggers adjacent to the existing loggers. These new loggers have relatively complete radiation shields that should yield a more accurate measurement of actual air temperatures inside the willow canopies, as well as relative humidity data. This data should complement the current "CUP" logger data.
Each site was also instrumented with two additional temperature loggers: a BASE logger which is attached to the base of the willow and which can be used to estimate the timing of snow burial and snow melt each spring, and a SOIL logger which records temperatures about 5 cm down into the soil beneath the willow. Eleven new mast-mounted weather stations were also planned for deployment in the three major study drainages, as soon as wilderness permitting is completed. These are designed to collect open-air climate data in the drainages, independent of the willow microenvironment. The working plan for collecting this weather and climate data is outlined on the weather data strategy pages. The team also posted the raw data from 10 years of in-canopy temperature measurement on a new password-protected "weatherbeetle" ftp site, making the data available to other investigators.
New sites were added to the network of beetle collecting and temperature logging sites. 4 sites were added along the Pine Creek drainage, halfway between Bishop Creek and Rock Creek. CUP loggers were also added along Baker Creek between Big Pine Creek and Bishop Creek. Many of these sites have been instrumented in the past but were discontinued in recent years for various reasons.
Team Beetle also established a private web log at http://willowbeetles.blogspot.com/ for keeping the team informed of each others' activities.
In December 2008 the Willow Beetle Project team was awarded a 5-year, $800,000 grant from the National Science Foundation, Division of Environmental Biology for the research proposal entitled "Collaborative Research, RUI: Ecological and evolutionary responses to environmental change in Sierra Nevada populations of a montane willow beetle." The award is a well-deserved boost for this research project which has been based at WMRS for nearly three decades.
The proposed research is focused on the evolution, physiology and ecology of Chrysomela aeneicollis, a species of Willow Leaf Beetle, living in the higher reaches of the Eastern Sierra drainages near Bishop. "Team beetle", consisting of Professsors Dahlhoff and Rank and WMRS Associate Director Smiley, and and their students and volunteers, will investigate how the beetles are responding to climate change. Are they moving their populations to new more favorable sites? Staying in place and coping? Evolving new traits? All of the above? How does genetic diversity at the PGI locus affect this adaptation? What is the role of heat shock proteins? The project draws on years of previous investigation by the senior scientists and their students, and includes detailed knowledge of the genetics, physiology, behavior, chemical ecology, predator ecology and temperature adaptations of the beetles. Much of this knowledge has been published in over 20 primary research articles (see reference list) and many student papers and theses. The project overview page has more information about the project and its history.