Amphinemura nigritta (Provancher)

Stark, Bill P. & Harrison, Audrey B., 2010, The Larva Of Amphinemura Alabama Baumann And New Records Of Nemouridae (Plecoptera) From Mississippi, U. S. A., Illiesia 6 (16), pp. 234-240 : 236-238

Amphinemura nigritta (Provancher)

( Figs. 6-10 )

Nemoura nigritta Provancher, 1876:217 .

Lectotype ♂, designation Ricker, 1952 (Quebec Provincial Museum), vicinity of Quebec City

Nemoura venosa Banks, 1897:21 . Synonymy, Ricker, 1952

Nemoura stylata Banks, 1920:324 . Synonymy, Ricker, 1952

Material examined. MISSISSIPPI: Claiborne Co.: Hwy 18, 2 miles north of Jones Village, 31 March 1978, B. Stark, 1♂ reared ( BYU). Little Sand Creek, Old Port Gibson Road, 32.06° N, 90.48° W, 9 March 1991, B. Stark, 10 larvae (BPS). Little Sand Creek, Rocky Springs, Natchez Trace Parkway, 1 April 1978, B. Stark, 1♂ ( BYU). Same site, 22 April 1978, B. Stark, 1♂ ( BYU). Natchez Trace Parkway (no other locality data), 13 April, 1997, R.E. DeWalt, 5♂, 3♀ ( INHS). Owens Creek, Owens Creek Natural Area, Natchez Trace Parkway, 31 March 1978, B. Stark, 2♂, 1♀ reared ( BYU). Same site, 8 April 1978, B. Stark, 2♂ ( BYU). Same site, 22 April 1978, B. Stark, 2♂ ( BYU). Ragsdale Creek, Regan Road, 32.05° N, 90.50° W, 24 February 1993, B. Stark, 7 larvae (BPS). Same site, 17 April 1993, B. Stark, 1♀ (BPS). Tributary Sand Creek, 1.5 miles north of Rocky Springs, Natchez Trace Parkway, 1 April 1978, 7♂, 9♀ reared ( BYU). Same site, 7 April 1978, B. Stark, 10♂, 14♀ ( BYU). Same site, 22 April 1978, B. Stark, 2♂, 3♀ ( BYU). Grenada Co.: T22N, R3E, Sec 31NW, 5-18 April 1992, G. Snodgrass, Malaise trap, 1♂, 1♀ (MEM). Lafayette Co.: Yellow Leaf Creek, Hwy 334, 13 April 1997, R.E. DeWalt, 1♂, 1♀ ( INHS). 3 miles SE Oxford, 28 April 1985, G. Dick, 1♂ (UM). Lincoln Co.: 1 mile NE New Sight, 31.40° N, 90.26° W, 22-29 March 2002, T.L. Schiefer, R.E. Wise, Malaise trap, 1♂, 1♀ (MEM). Same site, 29 March-5 April 2002, T.L. Schiefer, R.E. Wise, Malaise trap, 1♀ (MEM). Same site, 19-27 April 2002, T.L. Schiefer, R.E. Wise, Malaise trap, 1♀ (MEM). Newton Co.: Tonacana Creek, I-20, 15 April 1978, 6♂ reared ( BYU). Perry Co.: DeSoto National Forest, 30.58° N, 89.04° W, 11-19 April 2002, T.L. Schiefer, J. Schonewitz, Malaise trap, 1♀ (MEM). Smith Co.: 1 mile N Raleigh, 32.03° N, 89.31° W, 27 March-3 April 2002, T.L. Schiefer, J. Burrows, Malaise trap, 1♀ (MEM). Same site, 1-8 May 2002, T.L. Schiefer, J. Burrows, Malaise trap, 2♀ (MEM). Tishomingo Co.: Rock Quarry Creek, Tishomingo State Park, 34.37° N, 88.12° W, 25 May 2006, B. Stark, I. Sivec, 1♀ (BPS). Same site, 18 May 2009, B. Stark, 2♂ (BPS). Same site, 18 April 2004, J.G. King, 1♂, 1♀ ( BYU). Webster Co.: Tributary Lindsay Creek, The Cove, 7 miles west of Walthall, 30 March 1995, R.W. Baumann, T.L. Schiefer, 5♂, 3♀ ( BYU). Winston Co.: Tombigbee National Forest, 33.10° N, 89.04° W, 12 April 1999, T.L. Schiefer, 1♀ (MEM). Tombigbee National Forest, 33.13° N, 89.05° W, 5-12 April 1999, J. MacGown, T.L. Schiefer, Malaise trap, 3♂ (MEM).

Mature Larva. Body length ca. 6.0-7.0 mm. General color pale brown without distinctive pattern. Outer prosternal gills with 6-8 long slender branches arising in a whorl from a basal trunk. Pronotal margins almost completely fringed with thick setae of variable length ( Fig. 6 ). Pronotal disk with short thick spinules scattered over surface. Mesonotum with basolateral cluster of ca. 4-5 thick setae and fine marginal setae clustered basally and extending in a sparse row to apex ( Fig. 7 ). Fore femora bearing an outer grouping of thick setae from beyond midlength to near apex; finer setae occur apically and basally ( Fig. 8 ); femur without outer fringe setae, but ventral margin with fine short setae present; tibiae with sparse outer fringe and numerous thick setae along inner margin. Abdominal terga 8-10 with very poorly formed posterior whorls and few intercalary setae ( Fig. 9 ). Cerci with ca. 21 segments; setal whorls well developed from about segment 7 to apex, with longest setae on segments 12-18 ( Fig. 10 ). Longest cercal setae ca. three fourths as long as cercal segments; intermediate setae present beginning on about segment 10.

Comments. This species was previously known from five sites in Claiborne Co., one site in Hinds Co. and one site in Newton Co. The new records show the species is widely distributed throughout much of the state in areas of suitable habitat, typically from cool headwater streams with extensive riparian zones. The larval habitus has previously been illustrated (e.g. Frison 1935) and Harper & Hynes (1971) provide details of significant chaetotaxic characters and figures of the cerci and abdominal apex for Quebec and Ontario specimens. Our Claiborne County specimens have somewhat longer cercal setae and less conspicuous setae on the abdominal terga than specimens studied by Harper & Hynes (1971).

Figures

Figs. 6-10. Amphinemura nigritta larval structures. 6. Pronotum. 7. Mesonotum and metanotum. 8. Foreleg. 9. Abdominal terga 8-10. 10. Basal 17 cercal segments, lateral aspect.