Agent-based simulation of effects of stress on forest tent caterpillar (Malacosoma disstria Hubner) population dynamics

Authored by Jennifer Babin-Fenske, Madhur Anand

Date Published: 2011-07-24

DOI: 10.1016/j.ecolmodel.2011.04.014

Sponsors: National Science and Engineering Research Council of Canada (NSERC) Canadian Foundation for Innovation Canada Research Chairs program to M.A

Platforms: NetLogo

Model Documentation: Other Narrative

Model Code URLs: http://www.sciencedirect.com/science/article/pii/S0304380011002225#appd002

Abstract

The forest tent caterpillar (Malacosoma disstria Hubner) (FTC) has an outbreak cycle of approximately 10 years; however, smaller spatial scale analyses show some regions have longer or more frequent periods of high defoliation. This may be a result of local forest fragmentation, pollution or other sources of stress that may affect FTC directly or indirectly through stress on their hosts or parasitoids. Population dynamics of FTC were examined to investigate how stress may alter the severity and frequency of defoliation. We developed a spatially explicit agent-based model to simulate the host-parasitoid dynamics of FTC. Theoretical and empirically derived parameters were established using past literature and over 50 years of population data of FTC from Ontario, Canada. We find that increasing FTC fecundity, FTC dispersal or parasitoid mortality resulted in more severe outbreaks while a decrease in parasitoid fecundity or searching efficiency resulted in an overall elevation of defoliation. Parasitoid efficiency was the most effective parameter for altering the FTC defoliation. Since plant stress has been shown to alter several of these parameters in nature due to changes in food quality, habitat suitability, and chemical cue interference, our results suggest that forests affected by stressors such as climate change and pollution will have more severe and frequent defoliation from these insects than surrounding unaffected forests. As stressors such as drought and pollution emissions are predicted to increase in frequency or intensity over the next few decades, understanding how they may affect the outbreak cycle of a forest defoliator can aid in planning strategies to reduce the detrimental effects of this insect. (C) 2011 Elsevier B.V. All rights reserved.

Tags

Individual-based model Dispersal Forest tent caterpillar Host-parasitoid dynamics Insect outbreaks Malacosoma disstria Mortality Population cycles [email protected] Outbreaks Climate-change Canada Life-history Biological-control Lepidoptera-lasiocampidae Spalangia-cameroni Musca-domestica Insect pests Flesh flies