summer helps to explain the regal fritillary's univoltine life cycle. The larval diapause coupled with the adult female reproductive diapuase enables the larvae to maximize the benefits of fresh and abundant violet foliage when they are active in the spring (Kopper et al. 2001). Declining populations With a loss of more than 99% of the original native tallgrass prairie landcover today (Powell et al. 2006), decreased sustainable habitat area for the regal fritillary has become a real threat. Drastic declines in regal fritillary populations have led to much concern about the butterfly's future (Kopper et al. 2001). Historically, the regal fritillary's range extended from eastern Colorado to Maine. However, due to habitat loss and large-scale population declines, their range has been far reduced, especially in the east. From the 1960s through the early 1990s, eastern populations had declined so severely that only a few remain. (Powell et al. 2006) The regal fritillary was once present in 18 states east of Illinois. Today, only three populations remain in the eastern region. These populations have been located east of Indiana: Fort Indiantown Gap Pennsylvania, Radford Army Ammunition Plant in Virginia. Populations in the Midwest and Great Plains are much more widespread; however, they remain extremely vulnerable as their numbers continue to decline. The regal fritillary is not federally listed as an endangered species, but it has been assigned a NatureServe conservation status of G3, which is considered vulnerable (Selby 2007). S. idalia was a Category II species, or a possible candidate for listing under the Endangered Species Act, until 1996 when this category was eliminated by the federal government (Kelly and Debinski 1998). WildEarth Guardians submitted a new petition to list the species in 2013 (WildEarth Guardians 2013). The findings of formal review have not been published as of 1 May 2014. Threats The greatest threat the regal fritillary faces is habitat destruction (Powell et al. 2006). A number of factors continue to contribute to the loss, fragmentation, and degradation of the butterfly's habitat. Row crop agriculture, urban developments such as housing and business construction, road construction, and gravel mining all contribute to the disappearance and degradation of the prairies that regal fritillaries depend on. Since regal fritillaries require relatively non-degraded native tallgrass and mixed-grass prairies, the alteration of these landscapes has pushed them into a highly vulnerable status (Selby 2007). Largely due to the loss and degradation of the tallgrass prairie