Seasonal changes in the stonefly (Plecoptera) component of the diet profile of trout in Big Hunting Creek, Maryland, USA

The stonefly (Plecoptera) component of the trout diet profile was studied by analyzing 172 stomach pump samples collected between February, 1986, and December, 1989, in Big Hunting Creek, Maryland. Samples were obtained from a naturally reproducing population of brown trout (Salmo trutta) and a stocked population of rainbow trout (Oncorhynchus mykiss) caught between the boundaries of Catoctin Mountain Park and Cunningham Falls State Park. Eighty‐one of the samples contained a total of 1596 Plecoptera, 88% of which were adults. Twenty species were identified representing 7 families and 15 genera, with the dominant species being the winter stonefly, Allocapnia nivicola. Approximately 93% of the Plecoptera were represented by the winter stonefly species Allocapnia nivicola, A. granulata, A. recta, A. rickeri, Paracapnia angulata and Taeniopteryx maura. Recorded as a percentage of the total number of items recovered per month, stoneflies account for 47% (December), 82% (January), 70% (February), and 57% (Marc...