Biology of Willow Leaf Beetles

Ecological and evolutionary responses to environmental change in Sierra Nevada populations of a montane willow beetle.

Funded by the NSF Division of Environmental Biology

Symmorphus with beetle prey
Chrysomela aeneicollis with eggs

Parasyrphus maggot hunting beetle larvae

Individual web pages:

Project News:

The academic year 2010-11 included great progress in the genetics and physiology components of the project. An analysis of allozyme and mtDNA loci revealed that while the various beetle populations are structured geographically, the differences are not so high as to suggest substantial long term isolation. The field measurements on developmental rate indicated that beetle larvae with the "cool adapted" PGI-1 allele developed more slowly than the "warm adapted" larvae. The data also suggested that larvae at sites with cooler nighttime temperatures grew more rapidly than those at warm sites, perhaps suggesting some sort of energy savings during cooler nights. Field measurements of fecundity (# eggs laid per female) revealed that fecundity declined with elevation, and was lower in Big Pine Creek than the other two drainages. See 2010 summary of beetle project activities and findings for more detailed information.

Summer 2010 included a late snowmelt, and beetle project field activities were compressed into a correspondingly short summer. Beetle numbers were medium to abundant, and there was a distinct recruitment of beetles at the lowest elevation sites in late summer. We installed 11 new "mesoclimate" stations (see photo) in the Big Pine, Bishop, and Rock Creek drainages, and look forward to seeing the results in June 2011. We also carried out an investigation of fecundity and developmental rates in C. aeneicollis juvenile stages at different sites and elevations. We had a large failure rate (nearly 50%) among our HOBO PRO loggers; but in spite of that we have a nice data set to compare with the pendant loggers which seem to be much more reliable.

see beetle news web pages for older news about the project