Neotrichia mobilensis Harris

Harris, Steven C. & Rasmussen, Andrew K., 2010, The Neotrichia caxima Group (Trichoptera: Hydroptilidae) in the southeastern United States, Zootaxa 2608, pp. 25-44 : 26-27

Neotrichia mobilensis Harris

( Figs 1 , 2 )

Harris (1985): 252, 3,Ƥ

Neotrichia mobilensis was originally described from a small series collected from the Mobile River in Alabama. It has subsequently been collected in Texas (Moulton and Stewart 1997) and by Dr. Pat O’Neil and his colleagues at the Geological Survey of Alabama in streams and rivers of the Mobile Delta in Alabama.

The male of N. mobilensis is easily separated from other southeastern members of the N. caxima Group by the structure of the phallus, which has a single apical rod rather than the typical double rods, and an acute, subapical process ( Fig. 1 D). Although the female of N. mobilensis was described by Harris (1985), it is redescribed here and compared with other southeastern members of the N. caxima Group.

Redescription of female. Length 1.9–2.2 mm, 18 antennal segments. Brown in alcohol. Abdominal segment VII annular; segments VIII and IX narrowing apically, as in Fig. 12 B, sternum segment VIII with small tubular process ( Fig. 2 A), which is inconspicuous or lacking in some specimens; segment X narrowing apically, bearing lateral papillae. Bursa copulatrix as in Fig. 2 B, with posterior copulatory channel about same length as anterior genital chamber, this chamber sclerotized on margins and extending forward as small leglike processes, bell-shaped central sclerite.

As with the males, the females of N. mobilensis are atypical of other southeastern species of the N. caxima Group. In some of the specimens examined, the sternal plate on abdominal segment VIII seems to be absent, in others a small sclerotized tubular process is present ( Fig. 2 A), but all lack the large, conspicuous sternal plate seen in other species of the N. caxima Group.

Material examined. Alabama, Baldwin County, Jessamine Bayou @ Kettle Creek, N31.0122, W87.9260, 1 June 2004, P. O’Neil, 16 3, 4Ƥ; Bottle Creek tributary, N30.9558, W87.9362, 29 May 2004, P. O’Neil, 3163; Tensaw Lake, slough west of Dead Lake Island, N31.0503, W87.8954, 22 October 2003, P. O’Neil, 213; Proctor Creek @ New Hubbard Landing, N31.0732, W87.8781, 22 October 2003, O’Neil/Ford, 163; Red Hills Creek @ Tensaw Lake, N31.0899, W87.8701, 22 October 2003, O’Neil/Ford, 83; Mifflin Lake, Squirrel Bayou, N30.9559, W87.8953, 20 October 2003, O’Neil/Shepard, 43; Upper Briar Lake, North Rice Creek, N31.0181, W87.8889, 22 October 2003, O’Neil/Shepard, 28 3; Bayou Tallapoosa, East End, N31.0374, W87.9137, 22 October 2003, O’Neil/Ford, 493; Tensaw Lake @ inlet, N31.0488, W87.8711, 22 October 2003, O’Neil/Shepard, 1073, 37Ƥ; Mobile County, Mobile River @ Bucks, N31.0226, W88.0226, 15 May 2003, O’Neil/Shepard, 53; Dead Lake @ Dead Lake Marina, N30.9047, W87.9801, 15 May 2003, O’Neil/Shepard, 33; Washington County, Tombigbee River @ McIntosh Landing, N31.2565, W87.9888, 15 May 2003, O’Neil/Shepard, 453.

Distribution. AL, TX.

Figures

FIGURE 1. Neotrichia mobilensis, male genitalia. A. Left lateral view, B. Ventral view, C. Dorsal view, D. Phallus, left lateral view.

FIGURE 2. Neotrichia mobilensis, female genitalia. A. Abdominal segment VIII, ventral view, B. Bursa copulatrix, ventral view.

FIGURE 12. Neotrichia alabamenis, female genitalia. A. Abdominal segment VIII, ventral view, B. Abdominal segments VII – X, ventral view, C. Bursa copulatrix, ventral view. Abbreviations: abdominal segments = VII, VIII, IX, X; sternal plate = SP; posterior copulatory channel = PCC; genital chamber = GC; mesal sclerite = MS.