|Campbell, James - Jim|
Submitted to: Environmental Entomology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/7/2010
Publication Date: 6/1/2010
Publication URL: http://hdl.handle.net/10113/43389
Citation: Romero, S.A., Campbell, J.F., Nechols, J.R., With, K.A. 2010. Movement Behavior of Red Flour Beetle: Response to Habitat Cues and Patch Boundaries. Environmental Entomology. 39: 919-929. DOI: 10.1603/EN09324. Interpretive Summary: The ability of the red flour beetle, Tribolium castaneum, to find and colonize small patches of food is a major contributor to its pest status in food processing and storage facilities such as flour mills. Ability to use these small patches is influenced by both the distance from which animals perceive them (perceptual range) and how they interact with the edges of the patch. Here, we examined perceptual range of female red flour beetles by manipulating distance to a flour patch, starvation level, and airflow and measuring the number of individuals successfully locating the patch. Beetles appeared to typically respond to the patch only when it was physically encountered and starvation of beetles and presence of air flow did not increase patch detection. Additionally, we investigated how patch characteristics influenced tendency of beetles to enter the patch and the time spent in patches with different amounts of resource and shelter. At the first encounter with a patch edge, patches with tall edges (high-resource) were less permeable to beetles than patches with low edges (low-resource), even though they contained more food. Upon subsequent encounters, beetles entered high-resource patches more frequently than low-resource patches and left less quickly. Beetles entered covered patches more quickly than uncovered patches, suggesting that shelter may take precedence over amount of food as a factor influencing initial permeability. Identifying behavioral rules of movement may ultimately lead to more accurate predictions of how beetles use the environment and how the landscape pattern can be manipulated to reduce its suitability for this pest.
Technical Abstract: Exploitation of resource patches is influenced by both the distance from which animals perceive habitat (perceptual range) and permeability of patch boundaries. These interactions can play a key role in determining dispersal success and ultimately population distribution. Here, we examined perceptual range of female red flour beetle (Tribolium castaneum) by manipulating distance to a flour patch, starvation level, and airflow and measuring the number of individuals successfully locating the patch. Beetles appeared to only respond to the patch when it was physically encountered. Starvation level of beetles and presence of air flow over the patch did not significantly increase patch detection. However, we found a significant effect of resource on patch encounters at the greatest measured distance of 16 cm, suggesting that response may be hierarchically structured. Additionally, we investigated how patch characteristics influenced permeability to movement by recording the frequency of boundary transitions (frequency of immigration and emigration), and retention time in patches with different amounts of resource and shelter. At the first encounter high-resource patches were significantly less permeable to beetles than low-resource patches. Upon subsequent encounters, beetles immigrated into high-resource patches more frequently than low-resource patches and emigrated less frequently. Beetles crossed boundaries of covered patches more quickly than uncovered patches, irrespective of patch quality (resource amount), suggesting that shelter may take precedence over quality as a factor influencing initial permeability. In summary, our study highlights how permeability may change as individuals gain more information on patch quality during subsequent encounters. Movement models should consider that response to habitat boundaries may change with time and experience and that preference for shelter and propensity to aggregate along habitat and structural edges may profoundly impact the distribution of individuals at the landscape scale.