Larvae of Sarcophagidae (Insecta: Diptera) and their Relationship with the Pitcher Plants (Sarraceniaceae: Sarracenia) of Southeastern U.S. Bogs

Abstract

Larvae of diptera of the family Sarcophagidae from bogs in Mississippi, Alabama, and Florida were collected, reared, and identified to species. Additionally, the effect of sarcophagid larvae on nutrient uptake in white-topped pitcher plant leaves (Sarracenia leucophylla) was examined at Crawford bog in south Alabama. The influence of sarcophagid larvae on nutrition of pitcher plants has not been previously recorded in the literature. I reared Sarcophaga sarraceniae, Fletcherimyia abdita , and F. celarata from pitchers of S. leucophylla. In Alabama, all three species occurred at Crawford Bog while only S. sarraceniae and F. abdita occurred at Splinter Hill Bog. I reared F. abdita from pitchers of S. alata occurring in Desoto West Bog in Mississippi. Two species of sarcophagids, F. rileyi and F. jonesi, were reared from pitchers of S. flava. Both occurred at Sumatra Bog in Florida, while only F. rileyi was found at Crawford Bog. I also calculated sarcophagid larval frequencies in S. leucophylla and S. flava at Crawford Bog during 2004 and 2005. In 2004, 70% of S. leucophylla leaves surveyed contained at least one sarcophagid larva. In 2005, only 58% of leaves contained larvae, but among these, four were occupied by multiple larvae. Eighty-six percent and 94% of S. flava leaves in 2004 and 2005 respectively were occupied by at least one larva. During both years, 4 of the occupied pitchers contained multiple larvae.

Nutrition field experiments were conducted at Crawford Bog during the summers of 2004 and 2005. I demonstrated a strong positive relationship between the addition of prey and leaf concentrations of macronutrients (N, P, and K). In each experimental group, pitchers supplemented with prey and with prey plus larvae contained significantly higher nutrient levels than the other experimental conditions (except 2004 potassium control). Additionally, I demonstrated that larvae do not negatively affect plant nutrition. Pitchers supplemented with prey plus sarcophagid larvae showed a strong trend towards higher nutrient levels than pitchers with prey only.