Perlesta placida (Hagen), an eastern nearctic species complex (Plecoptera: Perlidae) BILL P. STARK Perlesta placida(Hagen), long regardedas a widespreadvariable species, is a complexof at least 12species which differ in pigmentation,egg morphology and male and femalegenital structures. Speciesremoved from the synonymyof P. placida(= Chloroperla virginicaBanks, 1898; = P. virginica immaculata Klapálek, 1921)include P.cinctipes (Banks, 1905),P. decipiens (Walsh, 1862)(= Perla brunnipennisWalsh, 1862,syn. n.; = Isoperla texanaBanks, 1914,syn. n.; = P. costalis Klapálek, 1921,syn. n.) and P. nitida Banks, 1948.New species described include P. ade- na, P. baumanni, P. bolukta, P. browni,P. lagoi, P. nelsoni and P. shubuta. Lectotypesare desig- nated for most older species,including P. frisoni Banks, 1948,which is also valid, and all are redescribedfrom types. B. P. Stark, Dept. of Biology,Mississippi College, Clinton, Mississippi,39058, USA. Perlesta was proposed by Banks (1906) for Perla perhaps another decade, I am presenting prelimi- placida Hagen, 1861 and defined by Needham & nary results based on examination of all types and Claassen (1925) to include small, brown, perlid selected samples of suitably prepared and associat- stoneflies with three ocelli and a yellow costal mar- ed material. These results indicate a minimum of 12 gin. Females have a moderately produced, medially species make up this complex, but several more are notched subgenital plate, and males are unique expected from regions which are poorly represented among nearctic Acroneuriinae in lacking a ham- in this study. mer. The genus may be an eastern nearctic endemic, but Wu described two Chinese (1938, 1948) species Materials and methods in the genus; these species are provisionally retained in Perlesta pending further study. Males collected at light traps, or reared from The synonymy given for Perlesta placida (Hagen) nymphs, were squeezed with forceps to fully ex- in Illies (1966) includes eight names, and reflects trude the penis sac. In order to minimize retraction opinions of Needham & Claassen (1925) and Frison of this structure, males were submerged in various (1942) that this is a widespread, highly variable spe- solutions including hot water, 8007oethanol, Car- cies. Many recent faunal, ecological, and be- noy's fixative, and KAAD, and held with forceps for havioral studies have followed this opinion (e.g. 1-3 minutes to maintain pressure on the genitalia Hitchcock 1974; Snellen & Stewart 1979; Lake 1980; until death occured. Mating pairs were collected Mingo 1983; Stewart & Huggins 1977) but others and preserved together; only pairs with genitalia en- (e.g. Stark & Gaufin 1976; Stark & Harris 1986; gaged were included, pairs where males were riding Kondratieff & Kirchner 1987; Feminella & Stewart loosely on a female were excluded. Some associa- 1986) have suggested P. placida is a species complex tions are based on similar color patterns, co-occur- in need of revision. rences, or rearings from similar nymphs. Since 1980, I have studied types, collected mating Male and female genitalia were examined after pairs from many localities, and accumulated males clearing with hot 1007oKOH. Eggs and the few with completely extruded genitalia in order to paraprocts studied with SEM were prepared follow- evaluate this putative complex. Because a compre- ing methods of Stark & Szczytko (1981). SEM study hensive study of all available specimens will require of penial armature required critical point drying of 264 Figs. 1-2.Periesta penis structure. 1. Fully extruded sac (S) of an undeterminedArkansas speciesshowing caecum (C), ventralextension (V), and dorsal patch (DP). The lateral sclerites(LS) of the tube (T) are united dorsally,and the envel- ope (E) is membranous.2. Partially extruded sac and tube of P. decipiens(from P. costalisholotype). The unextruded sac is denoted by diagonals.Scale = 0.15mm. uncleared, extruded genitalia prior to gold coating Monte L. Bean Museum, Brigham Young University for best results. (BYU). used in this are in col- Museum of Comparative Zoology, Harvard University Specimens study deposited (MCZ). lections of the following individuals and museums, National Museum of Natural History, Prague (NMP). or in the collection of the author (BPS). Holotypes ClemsonUniversity, Clemson, South Carolina (CU). of all new species are deposited in the United States Universityof Alabama, Tuscaloosa,Alabama (UA). National Universityof Mississippi,Oxford, Mississippi(UM). Museum, Washington (USNM). Universityof North Texas,Denton, Texas(UNT). C. H. Nelson, Chattanooga, Tennessee(CHN). B. C. Kondratieff,Fort Collins, Colorado (BCK). IllinoisNatural History Survey,Urbana, Illinois(INHS). R. F. Surdick, Front Royal,Virginia (RFS). 265 Figs. 3-6.Perlesta penisarmature. 3. P.placida, base of tube, 205x. 4. P. browni,apex of sac,405 x. 5. P. browni,dorsal patch, 1550 x 6.. P. placida, ventral sac extension,left 560 x, right 2790 x. Abbreviationsas in Fig. 1. Taxonomic characters with a small spine on the anteroapical margin (Figs. Internal male genitalia. - The penis of Perlesta spe- 9-11). Tergum 10 (T10) has a more heavily sclero- cies consists of three telescoping sections (Figs. 1-2) tized mesal region which is usually covered with which are armed with fine seta-like, sometimes mul- small to prominent patches of sensilla basiconica tibranched spines (Figs. 4-5). The short mesal tube (Figs. 7-8). section bears a pair of lateral sclerites (Figs. 1,3) Female genitalia. - The subgenital plate is a which sometimes unite dorsally, and scattered dor- moderately produced, slightly cleft or bilobed solateral sensilla (Figs. 3-4) which extend onto the structure. Frequently the posterior margins of the apical sac section. In most species the dorsomesal plate bear prominent setae. area of the sac protrudes over the ventroapical sac Egg. - Most Perlesta have eggs with short stalked extension to form a caecum; the dorsal surface of the collars and relatively smooth or slightly granular sac bears a prominent patch of seta-like spines. The chorionic surfaces (Figs. 12-15),but conical or but- ventroapical sac extension is long and densely coated ton-like collars (Figs. 19-20) and sessile collars with very fine seta-like spines (Fig. 6). The basal en- (Figs. 16-18) occur. The most common chorionic velop section (Fig. 3) is membranous, but sometimes modifications include irregular, shallow, pitting it is armed with small spinule-like structures. (Figs. 17, 19-20) and eclosion lines (Figs. 15, 17). External male genitalia. - Paraprocts are usually Micropyles have sessile, slanted orifices and form thin, moderately to strongly sclerotized, and armed an irregular circumlinear row near the posterior 266 Figs. 7-11.Perlesta externalgenitalia. 7. P. frisoni,T10 sensilla basiconicapatch, 65 x. 8. Same, 1300 x 9. P. decipiens, left paraproct, lateral aspect, 175x. 10.P. browni,left paraproct, lateral aspect, 305x. 11.P. sp., left paraproct, lateral aspect, 330 x . pole (Fig. 14). Anchor plates typically consist of a Key to adult Perlesta cluster of spaghetti-like fibers loosely covered by a membranous 1.Intercostal margin pale; paraprocts variable cap (Figs. 13,16). but typicallystraight or curvedmesad; subgeni- Nymphs. - A distinctive, freckled appearance tal plate lobes well developed, notch variable resulting from brown pigment spots at the bases of (Figs. 25, 30) ............................ 2 abdominal intercalary setae is typical of several spe- - Intercostal margin dark; paraprocts short and but others have a more brown curvedstrongly laterad (Figs.60-61 );subgenital cies, uniformly ap- lobes notch wide and All have an but plate slightly produced, pearance. species irregular, nearly shallow(Fig. 62) .................. P. baumanni complete, occipital setal row, and well developed 2. Wing membrane, veins and body pale; penis anal gills. without caecum (Fig.55) .................. 3 267 Figs. 12-20.Periesta eggs. 12. P. decipiens rfexas],145 x. 13. Same, 300 x .14. Same [Wyoming],600 x. 15.P. browni [Oklahoma],I50 x .16. P. placida [Mississippi],315 x. 17.P. cinctipes [Kansas],140 x .18. P.frisoni [Virginia],140 x. 19. P.bolukta [Oklahoma], 150 x.20. P. adena [Ohio], 180 x. 268 - Wing membrane amber to black, veins dark, Perlesta placida (Hagen) body with areas of dark pigmentation; penis with caecum (Fig. 1) ...................... 4 (Figs. 16, 21-26,102) 3. T10sensilla basiconica arranged in a pair of cir- cular, slightly elevated, dense patches; para- Perla placida Hagen, 1861.Lectotype 0' (MCZ # 253), procts short, stout, bearing a prominent mesal Washington, D. C. spine (Figs. 51-52);subgenital plate outline tri- Chloroperla virginica Banks, 1898.Holotype 9 (MCZ angular, notch V-shaped(Fig. 53) ....... P. frisonii # 11330),West Virginia. Syn. Needham & Claassen - T10 sensilla basiconica sparse (Fig. 65); para- (1925). procts slender (Figs. 65-67); subgenital plate Perlesta virginicaimmaculata Klapdlek, 1921.Lectotype outline rounded, notch U-shaped (Fig. 68) 9 (NMP), North Carolina. Syn. Needham& Claassen ................................... P. nelsoni (1925). 4. Wings dark brown to black; dorsal body color predominantlydark brown to black ......... 5 Male. - Forewing length 7-8 mm. General color yel- - Wings yellow-brownto amber; dorsal body low-brown. Head yellow except for brown quadran- color predominantlyyellowish .............. 7 gular area over ocelli, and small brown triangular 5. Paraproct spine extendingto midlength (Figs. area forward of median ocellus.