Amphinemura alabama Baumann

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 : 235-236

Amphinemura alabama Baumann

( Figs. 1-5 )

Amphinemura alabama Baumann, 1996:249 . Holotype ♂ ( United States National Museum), Alabama, Limestone Co., Cairo Branch , Elk River

Material examined. MISSISSIPPI: Tishomingo Co.: Clear Creek, Hwy 172, 34.37° N, 88.12° W, 18 May 2009, B. Stark, 3♂, 1♀ ( BYU) . Same site, 12 May 2010, B. Stark, 1♂, 3♀, 6 larvae ( BPS) . Clear Creek, Blythe Crossing , 12 May 2010, B. Stark, 1♀ ( BPS) .

Mature Larva. Body length ca. 7-7.5 mm. General color pale brown to brown, without distinctive pattern. Outer prosternal gills consisting of 6-7 long, robust branches arranged in a apical whorl from a basal trunk. Pronotal margins almost entirely fringed with stout setae; anterior margin with short setae near median suture with longer ones near anterolateral corners. Lateral pronotal margins with mostly longer setae; posterior margins poorly fringed ( Fig. 1 ). Mesonotum without conspicuous basolateral setae but fine outer marginal setae occur in the apical area ( Fig. 2 ). Fore femur with a few apical fringe hairs and a cluster of thick setae beyond midlength ( Fig. 3 ); ventral margin without conspicuous setation; tibial fringe sparse. Abdominal terga 8-9 with several long setae in posterior segmental fringe, but intercalary setae sparse or absent ( Fig. 4 ). Cerci with ca. 23 segments, setal whorls well developed from about segment 6 to apical segment with longest setae on segments 12-19 ( Fig. 5 ); longest cercal setae reach almost entire length of segment; segments beginning with ca.12 have intermediate fine setae arranged in irregular whorl pattern.

Comments. This species was previously known from Alabama ( Baumann 1996) and Kentucky ( Tarter et al. 2006), and, as indicated in the introduction, we suspect the female specimen from Tupelo determined as A. delosa by Stark (1979) might also represent this species. Unfortunately, that specimen was in the Bryant Mather collection and we are not certain where it was deposited after his death.

The larvae of A. alabama are very similar to those of A. nigritta but, in specimens examined, the setal whorls on most segments are comprised almost entirely of long setae, whereas in A. nigritta specimens, the smaller number of long setae are interspersed with a few short setae. In addition, the posterior setal whorls on abdominal terga 8-9 are more robust in A. alabama than in A. nigritta . Because the sample size for associated larvae of each of these species is small, these setal characters will need to be evaluated as more material becomes available.

Figures

Figs. 1-5. Amphinemura alabama larval structures 1. Pronotum. 2. Mesonotum and metanotum. 3. Foreleg. 4. Abdominal terga 8-10. 5. Basal 15 cercal segments, lateral aspect.