The Effects of Fire and Other Habitat Characteristics on Habitat Selection of Exyra ridingsii (Riley), the Riding’s Pitcherplant Looper Moth

Published:

June 2016

Author

Christine A. Ricci

Additional Authors

Albert J. Meier Ouida W. Meier T. Keith Philips

ABSTRACT Exyra ridingsii is a host-specific moth that spends its entire immature life cycle in the Sarracenia flava L. pitcher plant. Sarracenia flava requires a habitat that undergoes frequent fires and has acidic moist soil. During this investigation we studied the degree to which E. ridingsii damaged S. flava under different environmental conditions. From summer 2012 to fall 2013, five sites in the Croatan National Forest, North Carolina, were surveyed four times each year. At each site, 7 to 20 quadrats were randomly selected for sampling. In each quadrat, pitchers were counted and measured for height and whether the pitchers were affected by herbivory; the fraction affected was calculated (herbivory per clump). Median herbivory per clump at the burned sites ranged from 86– 100%. All other sites ranged from 50–75% with the exception of the unburned pocosin site, which was the lowest at 32%. Herbivory per clump was found to differ by site, but because sites varied in environmental characteristics other than burn status, other factors playing a role in habitat status cannot be ruled out. Tallest median trumpet heights were found at the unburned sites. During this study, E. ridingsii repopulated S. flava pitchers in the burned sites less than two months after fire, suggesting that they persist as a metapopulation.

Keywords

fire, Exyra ridingsii, habitat selection, Riding’s Pitcherplant Looper moth, Sarracenia flava, yellow pitcher plant