The spongy moth, Lymantria dispar, has been established in North America for over 150 years. Unlike most other non-native pests, this species exhibits massive outbreaks in its native range and comparison of outbreak behaviors among different world regions can provide insight. Because this species causes such extensive outbreaks, there has been great interest in understanding the processes that drive wide swings in abundance for the last 100 years in North America and elsewhere. In the context of this body of research, Joe Elkinton has made important contributions that have improved our understanding of the mechanisms driving the dynamics of spongy moth populations. Most notably, Joe’s creative studies on predation by small mammals showed that while predation has a huge impact on populations, it does not regulate populations. Prior to Joe’s work, the widely held dogma was that the functional response of predation to spongy moth density was a type III response and consequently positively density-dependent. Joe showed that predation was actually destabilizing and that the principle negative feedback in this system was provided by entomopathogens. Nevertheless, there still is a lot that we do not understand about spongy moth population dynamics. Most notably, we still know very little about what drives spatial synchrony in changes in population dynamics. Joe loves mysteries – while he has succeeded in solving some mysteries, he has also illuminated new mysteries as well.
