Speyeria idalia, butterfly, Violaceae, prairie, habitat fragmentation, extirpation
The Regal Fritillary butterfly, Speyeria idalia Drury (Lepidoptera: Nymphalidae, Argynninae), is a prairie endemic species which has exhibited a dramatic decline in Iowa during the last few decades. Tallgrass prairie is the primary habitat of S. idalia and the butterfly's presence is correlated with the presence of violets (Violaceae). Due to the extensive habitat fragmentation of Iowa prairies, both the butterfly and its host plant populations are limited primarily to unplowed, relatively pristine prairies. Thus, S. idalia is an excellent case study of a prairie endemic species. Here, we report on the results of a two-year survey of the insect and its host plants in Iowa. During 1995, we conducted extensive surveys of 52 prairies in southern Iowa and found S. idalia in 11 of those prairies. During 1996, we conducted more intensive surveys comparing eight Iowa prairies to prairies in Kansas, South Dakota, and North Dakota to examine the hypothesis that larval host plant limitation may be causing the decline of S. idalia. Our data show that Iowa prairies have lower hostplant availability and also have lower butterfly weights. We discuss the future prospects for the species and suggest various management scenarios that might aid in preserving the butterfly.
Journal of the Iowa Academy of Science
© Copyright 1998 by the Iowa Academy of Science, Inc.
Debinskl, Diane M. and Kelly, Liesl
"Decline of Iowa Populations of the Regal Fritillary (Speyeria idalia) Drury,"
The Journal of the Iowa Academy of Science: JIAS: Vol. 105:
, Article 4.
Available at: http://scholarworks.uni.edu/jias/vol105/iss1/4