Research interests

Bioenergy crops are continuously growing in importance as alternative energy sources, thereby emphasizing the value of understanding the ecology of herbivorous insects associated with the plants and the predator and parasitoid community linked to them. Despite this, the basic ecology of the insect communities is largely unknown. This is particularly true for the predator community in many arboreal crops such as willow (Salix) and aspen (Populus), often including various species of zoophytophagous plant bugs (Heteroptera: Miridae).

Zoophytophagous insects are plant feeding predators that rely on resources from more than one trophic level. Their life histories and population dynamics is likely to differ notably from those of herbivores or predators that are more directly associated with resources at only one trophic level. The main objectives of my research is to understand what drives population dynamics of so called “trophic switchers” and especially how factors such as host plant quality, surrounding landscape structure and local climate influence abundance and persistence of populations of zoophytophagous plant bugs. I am also interested in the often close association between plant bugs and their host plants, especially with respect to insect-host plant synchrony.

In this project I have chosen to work with two species of plant bugs (Orthotylus marginalis and Closterotomus fulvomaculatus) commonly occurring in natural stands of Grey Willow (Salix cinerea) using time series data on abundance of leaf beetles (Coleoptera: Chrysomelidae)  and plant bugs in different habitats. The same species are also highly abundant in willow plantations, providing ecosystem services as predators of highly variable and sometimes outbreaking leaf beetle populations. I mainly focus on the natural system, while trying to make comparisons between natural and managed habitats since I believe that this will give more broadly applicable results.

Allowing predator populations to establish and persist within or nearby fields is the key to reducing the likelihood for herbivore outbreaks. The potential for efficient conservation biological control in such perennial systems is high, much due to the low harvest disturbance frequencies, as compared to annual crops. Thus, with a better understanding of the ecology of these species and the interactions within the community, we may give constructive management advice that helps reducing herbivore outbreaks in willow plantations and other perennial crops.

Supervisors:

Professor Christer Björkman, Dept. of Ecology
Assistant Professor Peter Dalin, Dept. of Ecology

Publications

Björkman, C. & Liman, A-S. 2005. Foraging behaviour influences the outcome of predator-predator interactions. Ecological Entomology. 30: 164-169.

Links

 The Leaf Beetle Homepage