POTENTILLA FRUTICOSA (ROSACEAE) AS A NECTAR PLANT FOR BUTTERFLIES

Kleintjes Neff, Paula; Fettig, Stephen; VanOverbeke, Dustin

Despite its wide distribution, little documentation exists to confirm that butterflies use the woody shrub Potentilla fruticosa (Linnaeus) (Rosaceae) as a nectar plant. During the summer of 2004, we observed 36 individual butterflies belonging to 10 species nectaring on P. fruticosa in the Jemez Mountains, New Mexico. Butterflies spent 56% of total observed nectaring time on P. fruticosa, where it composed 26% of total blooming forb availability (out of 17 plant species). We used the anthrone method for carbohydrate analysis of P. fruticosa nectar samples and found significantly more carbohydrates (i.e., nectar) in flowers (n=68) excluded from nectivores (26.831.35 mg/2ml) than available (n=63) to nectivores (6.71+1.40 mg/2ml). Carbohydrate levels were also significantly higher in nectar later in the sampling season (Two-way ANOVA with repeated measures, p<0.05). Although anecdotal observations suggest that P. fruticosa is not a preferred nectar source for butterflies in the northern Rocky Mountains and in others areas of its range, our results indicate that P. fruticosa is an important nectar re- source for adult butterflies in the Jemez Mountains, New Mexico.