Alloperla prognoides Surdick & Stark, 2004

Ray, Donald H., Rasmussen, Andrew K., Peters, Janice G. & Stark, Bill P., 2010, The Larva And Egg Of Alloperla Prognoides (Plecoptera: Chloroperlidae), With Ecological Notes And New State Records From Florida, U. S. A., Illiesia 6 (19), pp. 256-266 : 257-259

Alloperla prognoides Surdick & Stark

( Figs. 1-21 )

Alloperla furcula: sensu Stark & Harris, 1986:177 , Not Surdick, 1981.

Alloperla prognoides Surdick & Stark in Surdick, 2004:20. Holotype ♂ ( United States National Museum), Little River , Hwy 59, Baldwin Co., Alabama.

Alloperla prognoides: Willet & Stark, 2009:117 .Redescription of male epiproct.

Material examined. New State Record. FLORIDA: Escambia Co, Pine Barren Creek, below US Hwy 29, N 30°46’30.04”, W 87°20’15.64”, 30 April 2008, D. Ray, G. Chiello, 3 adult ♂ (reared), 5 larvae. Same, except 22 April 2008 with F. Butera, 5 larvae. Big Escambia Creek , below Fannie Rd, N 30°58’50.4”, W 87°13’43.9”, 25 March 2010, 5 larvae, D. Ray, R. Abad. Same, except 28 April 2010, 1 adult ♂, 1 larva. Canoe Creek , above Bratt Rd, N 30°57’22”, W 87°20’49” 24, April 2009, D. Ray, R. Abad, 1♂, 3 larvae. Perdido River , 250 m above Brushy Creek confluence, N 30°47’37”, W 87°33’42”, 22 April 2009, D. Ray, R. Abad, 2♂ (reared) , 36♀ (2 reared) , 4 larvae. Pine Barren Creek , below US Hwy 29, N 30°46’30.04”, W 87°20’15.64”, 28 April 2009, D. Ray, R. Abad, 1♂ (reared) , 3♀ (reared) . Brushy Creek , above Pineville Road, N 30°47’47.6”, W 87°33’24.4”, 25 February 2008, D. Ray, L. Donelan, G. Chiello, 3 larvae .

Egg. Outline elongate oval. Length ca. 290 µm, width ca. 174 µm. Collar short, ca. 14 µm long and ca. 33 µm wide, and consisting of a single irregular row of large, irregularly shaped meshes ( Figs. 1-2 ). Chorionic surface covered throughout with fine micropunctures ( Figs. 2-3 ). Micropylar orifices somewhat tear drop shaped and at least twice as large as micropunctures ( Fig. 4 ); micropylar canals slanted.

Larva. Body length (not including cerci) 5.2-7.2 mm (n = 18); body slender, dorsoventrally flattened; general color pale brown, faint brown markings on head, thorax, and abdomen; legs pale; abdominal tergites with brown speckling anteriorly.

Head. Mandible with ca. 5 teeth, apical tooth scoopshaped; dorsal surface bearing a submarginal setal row more or less parallel to marginal setal row which terminates near base of tooth 4 ( Fig. 5 ); ventral surface with patch of acanthae near base of tooth 5; marginal setal row consisting of ca. 12 major setae. Maxillary laciniae with single apical tooth and prominent row of ca. 12 long setae ( Figs. 6-7 ). Postocular area with 2 long setae ( Fig. 11 ).

Thorax. Pronotal disk darkened marginally, body of sclerite uniformly pale brown. Pronotal setae arising antero- and posterolaterally; anterolateral setae set in cluster of 1 long seta and 5-7 shorter setae; posterolateral area with 2 widely spaced setae ( Fig. 11 ). Wingpad outer margins broadly rounded, inner margins slightly divergent; short setae scattered along lateral margins ( Fig. 12 ); distinct medial notch apparent during pre-emergent stage. Mesonotal setae of various lengths anterolaterally; group of short setae extending mesally near anterior margin. Foretibia with dorsal fringe of dense, very long hairs; sparse ventral fringe of long hairs, mixed with stout setae ( Fig. 13 ); apex set with several stout spine-like setae ventrally. Forefemora dorsally covered with many spine-like appressed setae; dorsal fringe of long hairs, denser distally; mix of long and short setae ventrally.

Abdomen. Sparse covering of fine, pale clothing hairs; posterior abdominal tergal margins fringed with short setae, incomplete mesally, pair of longer submesal setae, additional longer setae laterally ( Fig. 14 ). Cerci 10-12 segmented; plumate vertical fringe on distal half; dorsal fringe of intercalary hairs on posterior 4-5 segments ( Fig. 15 ); ventral fringe of intercalary hairs on posterior 5-6 segments; fringe somewhat more strongly developed along ventral margin than along dorsal margin; segmental cercal whorls consist of mixed setal types including groups of fine setae and larger, spine-like setae ( Figs. 8-10 ).

Remarks. As mentioned, larvae of most species of Alloperla remain undescribed; therefore, it is presently not possible to provide a definitive diagnosis. However, for the eastern Nearctic species for which detailed illustrations are available, A. concolor Ricker by Fiance (1977), A. natchez by Brown & Stark (1995), and A. imbecilla (Say) by Stewart & Stark (2002), a comparison of their illustrations reveals a number of potentially promising characters for distinguishing larvae of Alloperla species ( Brown & Stark 1995). Further comparison of the illustrations of the cerci from the publications listed above with Fig. 15 of this study shows that the larvae can be separated based on the number of cercal segments. The cercus comprises 10-12 segments in penultimate and last instar A. prognoides , whereas its sister species, A. natchez has 13 segments, A. imbecilla has 15-16 segments, and A. concolor has 18 segments. Additionally, A. natchez and A. prognoides have a cercal fringe of intercalary hairs which is more strongly developed dorsally than ventrally, whereas the dorsal and ventral fringes appear equally developed for A. imbecilla and A. concolor . Another character with diagnostic value is the setation of the posterolateral area of the pronotum, which in A. imbecilla has 4 posterolateral setae, compared with 2 posterolateral setae as seen in A. concolor , A. natchez , and A. prognoides .

The egg is very similar to that of A. natchez ( Brown & Stark 1995) in shape, collar form and chorionic detail, although the surface micropores of that species appear finer and more defined than in A. prognoides . Images of the male epiproct ( Figs. 16-21 ) are presented for comparison with those in Willett & Stark (2009) made from Alabama specimens.

Distribution. Alloperla prognoides is currently known from only Coastal Plain Alabama and the far western Florida panhandle (Escambia County). The species was first reported from Alabama (Baldwin, Escambia, Monroe Cos.) in Stark & Harris (1986) as A. furcula based on one male and 13 females collected between 11 May and 24 June. The authors noted that “the epiproct of the single male specimen is shorter and wider than in South Carolina specimens,” which suggested the specimen represented an undescribed species. Subsequently, A. prognoides was described by Surdick and Stark (2004) based on specimens collected in 1985 (late April-May) by Steve Harris from the Little River (Alabama: Baldwin, Monroe County) and Autauga Creek (Alabama: Autauga County). No other Alloperla species have been recorded from Coastal Plain Alabama or Florida. Other Alloperla species do occur in Alabama above the Fall Line: A. atlantica Baumann , A. caudata Frison , A. hamata Surdick , A. idei (Ricker) , and A. usa Ricker ( Stark & Harris 1986; Surdick 2004). There is always the possibility that one of these species, or another Coastal Plain endemic of Alloperla , overlaps in range with A. prognoides .

Figures

Figs. 1-4. Alloperla prognoides egg. 1. Entire egg. 2. Collar end. 3. Micropylar end. 4. Chorionic detail with micropyles.

Figs. 5-10. Alloperla prognoides nymphal structures. 5. Dorsal aspect of right mandible. 6. Ventral aspect of right lacinia. 7. Detail of lacinial apex. 8. Basal cercal segments, lateral aspect. 9. Cercal segment 7, lateral aspect. 10. Cercal segment 10, lateral aspect.

Figs. 11-15. Alloperla prognoides nymphal structures. 11. Head and pronotum. 12. Mesonotum and metanotum. 13. Foreleg. 14. Abdominal segments 7-10, dorsal aspect of male. 15. Cercus, lateral aspect.

Figs. 16-21. Alloperla prognoides epiproct structures, Pine Barren Creek, Escambia Co., FL. 16. Male terminalia, dorsal aspect. 17. Epiproct and cowl, dorsal aspect. 18. Apical half of epiproct. 19. Epiproct and cowl, lateral aspect. 20. Epiproct apex, frontal aspect. 21. Detail of basal epiproct surface.