​​​​​​​​​​The Brooks Lab
Linking Host Structure & Function to Consumer Dynamics​
The primary goal of the research in the BrooksLab is to understand the roles that variation among hosts in consumer-associated functional traits (e.g., defense mechanisms, nutritional value, etc.) and in structural topology (e.g., trophic or spatial structure) play in consumer invasion, dynamics and persistence. The core of this work focuses on the association between cactus moths and prickly pear cacti.
Background Information for the South American Cactus Moth
​Catford et al. (2009) provide an excellent distillation of the myriad studies of species invasions into one major hypothesis - that invasion success is driven by propagule pressure (P), abiotic conditions (A), and changes in biotic interactions (B). The contribution of each likely varies with any particular introduction. For example, the intentional introduction of Cactoblastis cactorum into Australia was clearly driven by propagule pressure. Dodd (1940) reared and spread approximately 3 billion eggs over Queensland and New South Wales. The drivers of the North American invasion are less clear - and this is where our efforts are focused.
P
B
A
Re-drawn from Catford et al. (2009).​
Abiotic Drivers: Environmental Niche Models as Hypotheses
Unlike the release of the South American cactus moth as a biocontrol organism, the introduction of this species into North America did not have the same massive propagule pressure to drive invasion success. If, however, the invasion was driven by abiotic conditions, we might expect that exotic populations would be found in similar environmental envelopes as native populations. Based on our extensive collections in Argentina and across Florida, there appears to be little evidence for C. cactorum invasion being driven by abiotic conditions (Brooks et al. 2012, Sauby et al. (2012).
Biotic Drivers: Current Focus​
All of our work to date in this system points towards invasion success being driven primarily through host-consumer interactions. Much of the work in the BrooksLab centers around hypotheses related to this idea (and details associated with continued analysis of propagule pressure and abiotic drivers).
