Agapetus hesperus Etnier, Baxter, and Parker, 2010

Etnier, David A., Parker, Charles R., John T. Baxter, Jr., Long, Todd M. & Drive, News Sentinel, 2010, A review of the genus Agapetus Curtis (Trichoptera: Glossosomatidae) in eastern and central North America, with description of 12 new species, Insecta Mundi 2010 (149), pp. 1-77 : 18-20

Agapetus hesperus Etnier, Baxter, and Parker new species

Fig. 11a, 11b, 11c . Map 11

Type material. Holotype, male MMT, length 5.3 mm, EX UT 1.967 . Tributary to Hubbard Cr. at Forest Service Road 210 bridge, Bankhead National Forest, 34.3052 o N, 87.4995 o W, Lawrence Co., AL, 15 April 2005, D.A. Etnier, P.L. Rakes, C.F. Saylor, J. R. and P.W. Shute. ( NMNH)

Allotype, MMT female pupa, same data as for holotype, emerged 28 April. ( NMNH)

Paratopotypes collected with holotype, all EX UT 1.967 . CASC, 15 April MMT male pupa, 2 May MMT female pupa ; CUAC, 18 April MMT male, 2 May MMT female pupa; INHS, 22 April MMT male, 20 April MMT female; ROME, MMT male, MMT female, both 9 May; SCHC, 15 April MMT male pupa, 27 April MMT female pupa; UMSP, 15 May MMT male, 11 May MMT female; UT 1.967 , 15 April MMT male, 2 MMT female pupae, 1 early pupa, all 15 April .

Additional material examined. Alabama, Colbert Co.: UT 1.824 , Buzzard Roost Spring run off Natchez Trace Parkway at US 72, 12 April 2002, 1 prepupa, 1 mature female pupa ; UT 1.965 , nw side of Natchez Trace Parkway 1.0 rd mi ne of Bear Cr. exit, 15 April 2005, 3 larvae /prepupae, 8 male + 10 female mature pupae/adults ; UT 1.966 , same locality but se side of Parkway, 15 April 2005, 2 prepupae, 2 early pupae, 5 male + 5 female mature pupae/adults ; UT 1.1012 , Hurd Spring run 1.4 rd mi n of co rd 20 on co rd 1, Margerum, 12 April 2002, 1 larva, 3 female mature pupae .

Diagnosis. Very similar to the form of A. avitus that has two pairs of denticles posteriad on X, but differing in having sides of X sclerotized (membranous in posteriodorsal area in A. avitus ), and in lateral view having a C-shaped notch between the terminal and subterminal denticle (no notch in A. avitus ). Further differing from A. avitus in having inferior appendage rhomboid and with one pair of sharply pointed, transverse denticles and two pairs of blunt denticles (ovoid with two pairs of sharply pointed, transverse denticles in A. avitus ). Similar to A. alabamensis , A. crasmus , A. diacanthus , A. gelbae , A. kirchneri , A. medicus , A. meridionalis , A. tomus , A. tricornutus , and A. vireo in having sides of X sclerotized and ventral edge more heavily sclerotized (more opaque); differing from all of these in the above described arrangement of the two pairs of posterior denticles on X.

Description. Male. Length 5.2-5.8 mm (n = 6). Male genitalia: Lateral view ( Fig. 11a ), anterior margin of IX slopes down and forward at 60 o to midline, where smoothly recurved down and back at 60 o to convex ventral margin; dorsal margin straight and sloping downward (20 o) toward X, 3/4 length of ventral margin; posterior margin with lateral shoulder sloping down and back to dorsal margin of preanal appendage base, then straight and vertical to ventral margin. Preanal appendage slightly clavate, length about 5 times depth, extending 1/2 distance to tip of X; about 8 erect setae on posterior 3/4 of exposed dorsal margin. Segment X sclerotized throughout, more heavily so on ventral arms which terminate in a sharp, upward curved denticle that extends well past the inferior appendage tip, a tiny denticle occasionally present on posterior margin ventral to terminal denticle. Ventral margin of X slopes down and back 1/3 distance to tip; then straight to near base of terminal denticle where it is smoothly curved dorsad to tip of denticle; angle formed between basal 1/3 and distal 2/3 of ventral arm about 150 o. Dorsal margin of X slightly concave on basal 1/3, then convex, terminating in sclerotized denticle at level of inferior appendage tip; a C-shaped notch between this denticle and the terminal denticle, neither denticle darker than ventral arms of X. Inferior appendage rhomboid, length = 3.2 times depth; concave dorsal edge and convex ventral edge diverge slightly to oblique and slightly concave posterior margin. Posterior margin slopes down and forward at 50 o. Submarginal denticle near posteriodorsal corner and two blunt denticles on ventral margin (one at posterioventral corner, one more distal), all on inner surface, visible as darkened areas; the two ventral denticles connected by a darkened ridge.

Dorsal view ( Fig. 11b ). Anterior margin of IX broadly and deeply concave; posterior margin visible as narrow suture; dorsal midline slightly thickened. Dorsal aspect of X fused on midline near base, then separated by membranous area, inner edges divergent at 20-30 o from each other to near dorsal pair of denticles; lateral margins of X parallel to body axis or slightly divergent; dorsal denticles diverge from body axis at 20 o. Ventral arms of X convergent from bases, meeting at 0.1 times length of X, then divergent at 20 o from each other and slightly and smoothly out-curved to posterioventral denticle. Posteriodorsal submarginal denticle on inferior appendage transverse, sharply pointed.

Ventral view ( Fig. 11c ). Anterior margin of IX slightly concave, posterior margin with angular posterior extension (100 o) between inferior appendage bases, a triangular depigmented area present delimited anteriad by a transverse band of setae. Inferior appendage base V-shaped, lateral and mesal sides at right angle. Outer margin nearly straight to bluntly pointed tip; inner margins in contact at base, divergent from each other at 30 o angle to blunt denticle at 2/3 length; this denticle followed by darkened, concave ridge, each ridge diverges from body axis at 40 o and terminates in a similar denticle. Submarginal posteriodorsal denticle as in dorsal view. Ventral arms of X conspicuous, smoothly curved outward from contact point at 1/4 length to non-darkened terminal denticle; posteriodorsal denticles barely visible laterally, 1/2 distance between end of membranous area and tip of X.

Larva. Head dark gray except for large, trapezoidal pale area that occupies nearly anterior 1/2 of genae, and a few pale, dark margined muscle scars behind eye visible on shed MMT sclerites. Frontoclypeus, pronotum, metanotal sclerites, and sclerites on IX and X concolorous, as dark as head. Mesonotal sclerites paler, with 3 darker freckles on outer margin. Prosternum with outer edge about 1.5 times length of median edge. Mesosternal sclerites black except for median yellow area. Legs pale. Legs, sterna, and sclerites on IX and X otherwise typical for genus.

Emergence dates. 18 April-17 May.

Distribution. AL Colbert (3), Lawrence.

Discussion. Occurs syntopically with the very similar A. avitus . Because A. avitus is an extremely variable species, it seems likely that additional records of A. hesperus are lurking in collections under the name A. avitus .

Etymology. hesperus = western, the most westerly distributed of species confined to the area east of the Mississippi River.

Figures

Figure 10-12. Agapetus spp. male genitalia. 10) Agapetus harrisi Etnier, Parker, and Baxter. 10a, lateral view; 10b, dorsal view; 10c, ventral view of IX and inferior appendages. 11) Agapetus hesperus Etnier, Baxter, and Parker. 11a, lateral view; 11b, dorsal view; 11c, ventral view, preanal appendages not shown. 12) Agapetus hessi Leonard and Leonard. 12a, lateral view; 12b, dorsal view; 12c, ventral view of IX and inferior appendages.