The life history of Pteronarcys dorsata (Say) (Plecoptera: Pteronarcyidae) in southwestern Virginia

Abstract

The life history of the giant stonefly Pteronarcys dorsata was investigated in a warm water fourth order river in southwestern Virginia. The life cycle of P. dorsata was univoltine with emergence occurring mid-March to 1st week of April. Adults lived up to 42 days in the laboratory. Mean fecundity was 242 eggs with up to four separate egg batches produced. Eggs hatched in 23 to 38 days. Early nymphal instars were collected in the river in mid-June. Nymphs reached maximum size by late November or December. During the warm months nymphs were found in mats of Podostemum ceratophyllum (river weed) and through the winter months under large unembedded rocks or leaf packs. The diet consisted of diatoms and detritus. Higher water temperatures of longer duration in the Little River probably allowed this species to complete its life cycle in 1 year rather than the 2 to 4 years previously reported.

Stable carbon and nitrogen isotope analysis of seston in a regulated Rocky Mountain river, USA

“…Precedent for Pteronarcys consuming fine autochthonous particles exist (e.g. Shepard, 1980;Lechleitner and Kondratieff, 1983). Freilich (1991) examined food habits of P. californica in a Wyoming tributary of the Snake River.…”

Green leaves enhance the growth and development of a stream macroinvertebrate shredder when senescent leaves are available

“…Some of the shredder species may then switch to alternative food such as periphyton (e.g. Lechlettner & Kondratieff, 1983; Ledger & Hildrew, 2000), but others might suffer from food shortages during their critical growth and development stages.…”

Modelling the possible impacts of climate change on the thermal regime and macroinvertebrate species of a regulated prairie river

“…Pteronarcys dorsata (Plecoptera: Pteronarcydae) have an upper limit for emergence of 25°C and thermal feeding optima of 20°C (Nebeker, 1971). Climate projections for monthly instream flow temperature changes by 2040 and 2080 in the current model suggest the conditions will be extremely challenging for this group to live as the upper emergence limit would be exceeded (Lechleitner & Kondratieff, 1983). Stoneflies in general can be reasonably expected to largely disappear in the most extreme scenarios of this model (Ernst, Beitinger, & Stewart, 1984;Heiman & Knight, 1972;Poulton, Beitlinger, & Stewart, 1989) because the critical upper temperature limit for P. dorsata is high relative to that of other stoneflies (Shoup and Diamesinae taxa (Phillips et al, 2015), and warming will cause them to be replaced by warm water taxa in the Chrinominae subfamily (Marziali & Rossaro, 2013).…”