Comparing the effect of native and introduced grasses on the development of least skippers (Lepidoptera: Hesperiinae: Anycloxypha numitor)

Grass skippers (subfamily Hesperiinae) are small butterflies that feed on grasses and sedges and are common in grasslands in the midwest.  While some native species of grass skippers, such as the Poweshiek skipperling (Oarisma poweshiek), Arogos skipper (Atrytone arogos), Dakota skipper (Hesperia dacotae), and Ottoe skipper (Hesperia ottoe), are restricted to high quality prairies remnants (Schlicht & Orwig 1998) and are considered prairie “specialists,” other closely related native species of grass skippers such as the Least Skipper (Ancyloxypha numitor) and Fiery Skipper (Hylephila phyleus) are able to survive in a wide range of habitats, and are considered generalists.  Research was conducted on the ability of the larvae of two generalist species common to northeast Iowa- Ancyloxypha numitor and Atalopedes campestris- to consume different grasses in order to determine whether the proliferation of certain skipper species over others is due to their ability to consume exotic grasses as well as generalist native grasses and b) to determine which host plant produces the healthiest individuals.  Results from this experiment will help determine if the negative consequences fire and other prairie management techniques can have on prairie specialist species (Schlicht & Orwig 1998, Swengel 1996) can be attributed to the different vegetative composition and structure of native and invasive grasses found in restored prairies (Vogel et al. 2010, Swengel 2001), based on the ability of the butterflies to utilize these grasses.