The larval head widths at each instar, life cycles, and food habits of late instars were determined for five species of Rhyacophila from two Appalachian mountain streams in South Carolina, U.S.A. Rhyacophila acutiloba Morse & Ross was univoltine with two cohorts, one emerging in the spring and another presumably emerging in early autumn. Rhyacophila fuscula (Walker), R. nigrita Banks, and R. Carolina Banks were apparently multicohort, univoltine species with extended flight periods. Rhyacophila minor Banks was univoltine with a spring emergence. All species were predaceous and consumed mainly Plecoptera nymphs and Trichoptera larvae.

The triploid Grass Carp Ctenopharyngodon idella has been used to control hydrilla Hydrilla verticillata infestations in southern U.S. reservoirs for several decades. After eliminating hydrilla in the water column, Grass Carp must be maintained in sufficient densities to control hydrilla regrowth from the tuber banks in the hydrosoil. We monitored the long‐term response of triploid Grass Carp populations that had eliminated hydrilla within the water column in two Piedmont (Lake Norman and Mountain Island Lake, North Carolina) and two Coastal Plain reservoirs (the Santee Cooper system comprising Lakes Marion and Moultrie, as well as the connecting canal in South Carolina). Triploid Grass Carp stocked in Lake Norman and Mountain Island Lake exhibited both slow growth and erratic, but potentially high, mortality. Due to erratic survival in the two Piedmont reservoirs, we could not estimate mortality using a catch curve. Fish stocked into the Santee Cooper system not only grew larger and faster, they also persisted (i.e., significant numbers of age‐16–21 fish were collected during sampling in 2011). We hypothesize that Piedmont reservoirs without hydrilla in the water column and with little naturally occurring aquatic vegetation have a very low carrying capacity for triploid Grass Carp. Consistent, long‐term survival of triploid Grass Carp in the Santee Cooper system may be due to available food provided by hydrilla regrowth in the water column, floating vegetation, and less‐palatable, native, submersed vegetation. Hydrilla management in systems with residual plant food could involve estimating an average mortality rate and maintaining enough fish (i.e., about one fish per four hectares of surface area) to control hydrilla regrowth. In Piedmont reservoirs, possible management alternatives could include maintenance stockings based upon (1) yearling stocking rates that were successful in the past, (2) stockings determined from indirect measures of mortality such as from von Bertalanffy growth equation parameters, or (3) stockings derived from measures or indices of abundance such as counts conducted at night by bowfishers. Received January 28, 2014; accepted April 20, 2014

We developed a three‐step management strategy for hydrilla Hydrilla verticillata in five Piedmont reservoirs operated by Duke Energy Corporation. This strategy involves (1) early detection of hydrilla, (2) use of registered herbicides for plant suppression along with stocking 20 triploid Grass Carp Ctenopharyngodon idella per surface acre of infestation, and (3) maintenance stocking of triploid Grass Carp to prevent hydrilla regrowth from tubers. Following this strategy, hydrilla in the water column was eliminated within one calendar year after Grass Carp introduction in four out of five reservoirs. This suggests that integrating herbicide applications with stocking Grass Carp largely eliminates the multiyear lag effect normally associated with using Grass Carp alone. A maintenance density of at least one triploid Grass Carp per eight surface acres of the reservoir prevented hydrilla regrowth except for a brief and minor reinfestation in one of five study reservoirs. This management approach proved successful when hydrilla coverage was as little as 1–3% of the reservoir's surface area. Detecting and controlling hydrilla early during the infestation should reduce the cost of management and perhaps minimize some adverse effects associated with the introduction and use of triploid Grass Carp.Received November 14, 2012; accepted January 15, 2013

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