Specimens of Cryptopygus bipunctatus are reported and described from North America (Michigan) for the first time. The species is easily recognized by its lack of color, one pair of ocelli on black eyespots, and one flair of ventral manubrial setae. Michigan and European specimens are very· similar. A very similar Polish species, Isotomina posteroculata, is transferred to Cryptopygus

Bernard, E. C

Snider, R. J

English

Valparaiso University

The Great Lakes Entomologist Volume 27 Number 3 - Fall 1994 Number 3 - Fall 1994 Article 4 October 1994 Cryptopygus Bipunctatus (Collembola: Isotomidae) in North America, and C. Posteroculatus N. Comb. E. C. Bernard University of Tennessee R. J. Snider Michigan State University Follow this and additional works at: https://scholar.valpo.edu/tgle Part of the Entomology Commons Recommended Citation Bernard, E. C. and Snider, R. J. 1994. "Cryptopygus Bipunctatus (Collembola: Isotomidae) in North America, and C. Posteroculatus N. Comb.," The Great Lakes Entomologist, vol 27 (3) Available at: https://scholar.valpo.edu/tgle/vol27/iss3/4 This Peer-Review Article is brought to you for free and open access by the Department of Biology at ValpoScholar. It has been accepted for inclusion in The Great Lakes Entomologist by an authorized administrator of ValpoScholar. For more information, please contact a ValpoScholar staff member at scholar@valpo.edu. 1994 THE GREAT lAKES ENTOMOlOGIST 149 CRYPTOPYGUS BIPUNCTATUS (COLLEMBOLA: ISOTOMIDAE) IN NORTH AMERICA, AND C. POSTEROCULATUS N. COMB. E. C. Bernard! and R. J. Snider2 ABSTRACT Specimens of Cryptopygus bipunctatus are reported and described from North America (Michigan) for the first time. Tbe species is easily recognized by its lack of color, one pair of ocelli on black eyespots, and one flair of ventral manubrial setae. Michigan and European specimens are very· similar. A very similar Polish species, Isotomina posteroculata, is transferred to Cryptopy· gus. Cryptop;xgus bipunctatus (Axelson) (= Isotoma bipunctata Axelson) is widely distnbuted in Europe (Stach 1947, Gisin 1960), but usually has not been considered pa t of the North American fauna. Hammer (1938) reported I. bipunctata from east Greenland, but Agrell (1939) considered her specimens to be I. notabilis pallida Agrell. Mills (1939) reported specimens from Mani­toba, but Christiansen and Bellinger (1980) believed they probably were I. notabilis Schaffer or I. ekmani Fjellberg. Dallai (1969) transferred I. bipunc­tata to Cryptopygus Willem. In 1972, Michigan specimens identified as C. bipunctatus were collected during surveys of Collembola around wastewater treatment sites. Because this taxon has not been reliably described or reported from North America, a detailed description is given of the Michigan specimens, which were compared to European specimens. MATERIALS AND METHODS Michigan specimens were extracted with Tullgren. funnels from soil col­lected from grassy areas at the Belding Sewage Treatment Facility, Ionia County, Michigan, then pennanently mounted on slides. For comparison, specimens collected in Europe were solicited from several individuals and institutions. All drawings were made with the aid of a drawing tube. In the description, we refer to thoracic and abdOininal segments as TH I, TH II, TH III, ABD I, ABD II, ABD III, ABD IV, and for the final two, fused segments, ABD V + I. Setae in the posterior, transverse row of each segment are desig­nated as pI, p2, etc., where pI is the seta closest t the dorsomedian line. IDepartment of Entomology and Plant Pathology, P. O. Box 1071, The University of Ter,nessee, Knoxville, TN 37901-1071. Department of Zoology, Michigan State University, East Lansing, MI 48824. 1Bernard and Snider: Cryptopygus Bipunctatus (Collembola: Isotomidae) in NorthPublished by ValpoScholar, 1994150 THE GREAT LAKES ENTOMOlOGIST Vol. 27, No.3 Cryptopygus bipullctatus (Axelson) Cryptopygus bipunctatus Dallai, 1969. Redia 51:238. =Isotoma bipunctata Axelson, 1903. Acta Soc. Fauna Flora Fenn. 25:9. =Proisotoma (Isotomina) bipunctata Gisin, 1943. Rev. Suisse Zool. 50:162. =Proisotomodes bipunctata Bagnall, 1949. Ann. Mag. Nat. Hist. 12:84. =Pansotoma bipunctata Hazelton and Glennie, 1953. British Caving (C. D. H. Collingford, ed.):273. = Iso to mina bipunctata Gisin, 1960. Collembolenfauna Europas:200. Dallai (1969) transferred Isotomina bipunctata to Cryptopygus on he basis of the synonymization of Isotomina Bomer and Cryptopygus by Mas­soud and Rapoport (1967), but did not take into account the other combina­tions proposed for this species over the years. A brief exposition of its history is warranted. The taxon described as Isotoma bipunctata frequently has been shifted among several genera, due to its unusual morphological features. Axelson (1903) differentiated 1. bipunctata from other Isotoma spp. on the basis of one pair of ocelli on pigmented spots and simple body setae. Other characteristics given by Axelson and important to placement of the species are unguis with­out teeth, tibiotarsus without clavate tenent hairs, tenaculum corpus with one seta, and two mucronal teeth. Stach (1947), thoroughly redescribing the spe­cies, found that the fifth and sixth abdominal segments were fused, th fifth abdominal tergite had one pair of blunt sensilla, a d the manubrium pos­sessed one pair of ve trod stal setae. He considered 1. bipunctata to be an unusual species for which a new genus eventually would be needed. Gisin (1943) placed the species in Proisotoma (Isotomina) and later (1960) in Iso­tomina on the basis of the two ventral manubrial setae, slender dentes, and fused fifth and sixth abdominal segments. Bagnall (1949) established the genus Proisotomodes, with 1. bipunctata as its type and only species. Proiso­tomodes was differentiated by the small size of the body, tenaculum with one seta, manubrium with one pair of ventral setae, and bidentate mucro. Gisin (1960) regarded Proisotomodes as a synonym of Isotomina. Hazelton and Glennie (1953) listed the species in Pansotoma Bagnall, but it is clear from Salmon's discussion (1964) that if Pansotoma is a valid genus, it must be restricted to species with 4-6 pairs of eyes. Gisin (1960) considered Panso­toma a synonym of Isotoma. Willem (1901) briefly described a new genus and species, Cryptopygus antarcticus, separated from other taxa on the basis of the "sixth abdominal segment usually invisible from above, der.ressed downward by the fifth abdominal segment" (see also Stach 1947. Willem's illustration suggests ankylosed fifth and sixth abdominal segments. Willem also described and illustrated a shor furcula with subequal manubrium and dens, and a biden­tate mucro. Historically, Isotomina Bomer 1903 was differentiated from other isotomid taxa by having a partially divided postantennal organ, smooth body setae, fused fifth and sixth abdominal segments, and dens longer than the manubrium. Massoud and Rapoport (1968) considered that both Cryptopygus and Isotomina had fused fifth and sixth abdominal segments, and thus regarded Isotomina as a junior synonym of Cryptopygus. The genus Cryptopygus is now defined as Isotomidae with fused fifth and sixth abdominal segments, few ventral manubrial setae, two mucronal teeth, and PAO often constricted or with a median listel (Christiansen and Bellinger 1980). Isotoma bipunctata clearly' fits this concept of Cryptopygus. It is excluded from Isotoma because It has only one pair of ventral manubrial setae, not many. The genera Isotomina and Proisotomodes, to which 1. bipunc­2The Great Lakes Entomologist, Vol. 27, No. 3 [1994], Art. 4https://scholar.valpo.edu/tgle/vol27/iss3/41994 THE GREAT LAKES ENTOMOLOGIST 151 tata has been referred, are junior synonyms of Cryptopygus. The definition of Pansotoma as given by Salmon (1964) does not acconunodate l. bipunctata. DESCRIPI'ION OF MICHIGAN SPECIMENS Color and Size: White except for black eyespots (Fig. 1). Length = 486-647 fUll, mean = 590 /Lm (n 6). Head: Postantennal organ (PAO) oval, length 3.5-5 X the width of the ocellus, wall irregularly thickened, median lister present or absent (Figs 2, 3), One ocellus on each side of the head, adjacent to the PAO, pigment granules large and distinct, frequently spreading onto PAO (Fig. 2). Antenna slightly longer than length of head, ratio of segments I:II:III:IV as 1:1.5:1.6:2.9. Seg­ment I with short, thorn-like seta dorsally (Fig. 7), one large and one small sensilla ventrally (Fig. 6); segment II without differentiated sensilla; segment III with one thorn-like seta, and sense organ consisting of two small club­shaped sensilla in pits, flanked on each side by a longer sensillum (Figs. 4, 5); selPl1ent IV with numerous pointed and blu t sensilla, pin seta simple, bluntly pomted (Figs. 4, 5); subapical pit and sensory rod not seen. Labrum with five subapical and four apical setae, anterior margin smooth (Fig. 8); mandible of typical isotomid form, apically truncated (Fig. 9), with four anterior teeth and large molar region; maxilla with tridentate capitulum and apparently six fringed lamellae (Fig. 9); maxillary outer lobe with trifurcate maxillary palpus, the apical digit the longest, and two basal setae; sublobal plate apically smooth, basally with three seta-like projections (Fig. 9). Legs: Unguis and unguiculus untoothed, pr tarsus with one pair of setae, clavate tenent hairs absent. All leg setae smooth and acuminate. Foreleg (Figs. 10, 11) with two long, precoxal setae, coxa without setae; trochanter with two exterior and two interior setae; tibiotarsus with a subapical whorl of seven setae. Mesoleg precoxae I and II with two and six setae, respectively; coxa with nine setae; trochanter with nine setae (Figs. 12, 13); tibiotarsus ventrally with five pairs of setae, dorsally with three longitudinal rows of setae (Figs. 14, 15). Metaleg (Figs. 16, 17) precoxae I and II with four and five setae, respectively; coxa with nine setae, most of them in a transverse row; trochanter with nine setae; femur with many exterior setae, few interior setae; tibiotarsus with four pairs of ventromedian setae. Abdomen: Ventral tube with four pairs of lateral setae and one pair of caudal setae (Fig. 21). Each tenaculum ramus with four teeth, tenaculum corpus with one anterior seta. Furcula (Fig. 18) well developed, dens about twice he length of the manubrium; manubrium with 16 pairs of dorsal setae and one pair of ventral setae setae, apically with two small teeth; dens crenu­late, with three rows of setae; subterminal seta extending slightly past furcula terminus; mucro bidentate, apical tooth larger than anteapical tooth. Chaetotaxy: All common setae smooth and acuminate (Figs. 19, 20)Seven unpaired dorsomedian setae on head; seta pI shorter than p2. All body sensilla th n except on ABD V +VI. Each side of TH II tergum with three anteriolateral sensilla; TH III tergum with two posterior sensilla and oneanteriolateral sensillum; TH III sternum with two setae. ABD I with one sensillum between p4 and p5, and another between p9 and pIO; ABD II with one sensillum between p4 and p5, and another near the lateral margin; ABD III with a sensillum between p4 and p5, and another near the posteriolateral margin; ABD IV with two sensilla, one between p2 and p3, another between p4 and p5; ABD V + I on each side with one plump laterodorsal sensillum and one thin ventrolateral sensillum. Collection Data: Six female and late subadult specimens collected from 3Bernard and Snider: Cryptopygus Bipunctatus (Collembola: Isotomidae) in NorthPublished by ValpoScholar, 1994152 THE GREAT LAKES ENTOMOLOGIST Vol. 27, No.3 ('I') ..... E v , E E E 0'"o 0 0 0N N N .... Figures 1-8. Cryptopygus bipunctatus. 1. Habitus. 2. Postantennal organs (PAO's, and eyespots. 3. Variation in shape of postantennal organ. and location of ocelli. Arrows indicate PAO's from the same specimen. 4. Antenna! segments III+IV, exterior view. 6. Antennal segments III+IV, interior view. 6. Antennal segment I, ventral view. 7. Antennal segment I. dorsal view. 4The Great Lakes Entomologist, Vol. 27, No. 3 [1994], Art. 4https://scholar.valpo.edu/tgle/vol27/iss3/41994 THE GREAT LAKES ENTOMOlOGIST 153 10~ " ,y / , ~--- .... .........•o.... e e e\.ri:N N Figures 9-17. Ciyptopygus bipunctatus. 9. Mouthparts (L-r.): apex of maxilla; maxil­lary palpus and sublobal plate; apex of mandible. 10. Foreleg, exterior view. 11. Foreleg, interior view. 12. Mesoleg, exterior view. 13. Mesoleg, interior view. 14. Mesotibiotar­sus, dorsal view. 15. Mesotibiotarsus, ventral view. 16. Metaleg, exterior view. 17. Meta­leg, interior view. 5Bernard and Snider: Cryptopygus Bipunctatus (Collembola: Isotomidae) in NorthPublished by ValpoScholar, 1994154 THE GREAT LAKES ENTOMOLOGIST Vol. 27, No.3 Figures 18-21. Cryptopygus bipunctatus.18. Furcula. 19. Chaetotaxy of head, thorax, and abdominal segments I-III, left side (sensilla indicated by s and arrowl. 20. Chaeto­taxy of abdominal segments IV-V+VI (sensilla indicated by s and arrow). 21. Venter of metathorax and abdominal segments I-II. 6The Great Lakes Entomologist, Vol. 27, No. 3 [1994], Art. 4https://scholar.valpo.edu/tgle/vol27/iss3/41994 THE GREAT LAKES ENTOMOLOGIST 155 sandy, moist soil at the edge of deciduous secondary forest, Belding Sewage Treatment Facility, Ionia County, Michigan, 25 July 1972, Renate M. Snider and Ernest C. Bernard, collectors. Diagnosis: The combination of one pair of ocelli on black eyespots, one pair of plump sensilla on ABD V +VI, one pair of ventral manubrial setae, and bidentate mucrO distinguishes C. b punctatus from most other Collembola. The species described by Stach (1947) as Isotomina posteroculata has each ocellus distant from the PAO and has a toothed unguis. Other Isotoma-like taxa with only one pair of ocelli have numerOus ventral manubrial setae and tridentate or quadndentate mUCrones. Discussion: Specimens of European C. bipunctatus from Vienna, Austria; Puglia, Italy; Tjome, Norway; and Budleigh, Salterton, England, were all very similar in structure and sensillar chaetotaxy to the Michigan specimens, and to the description given by Stach (1947). Isotomina posteroculata is so similar to c. bipunctatus that the two could be considered the same species. However, the wide separation of the PAO and ocellus, and the toothed unguis, serve to separate the two taxa. Because of the great similarity, 1. posteroculata is transferred to Cryptopygus: Cryptopygus posteroculatus (Stach) n. comb. Isotomina posteroculata Stach, 1947. Polish Acad. Sci. Lett., p. 278. ACKNOWLEDGMENTS We are grateful to Dr. Erhard Christian, Vienna, and Ms. Suzanne Lewis, British Museum (Natural History), for kindly lending us specimens of C. bipunctatus, and to Dr. Arne Fjellberg, Tjome, Norway, for sending freshly collected specimens from Norway. We also thank Dr. Peter Bellinger for his assistance with the literature. ' LITERATURE CITED Agrell, I. 1939. Em Vergleich zwischen I sotoma bipunctata Axelson und paUida-Formen von Isotoma notabilis Schaffer. Kungl. Fysiografiska Sallskapets I Lund Forhandlingar 9:1-4. Axelson, W. M. 1903. Weitere Diagnosen uber neue Collembolen·Formen aus Finland. Acta Soc. Fauna Flora Fennica 25:1-13. Bagnall, R. S. 1949. Contributions towards a knowledge of the Isotomidae (Collembola)-VII-XV. Ann. Mag. Nat. Hist. (Ser. 12) 2:81-96. Christiansen. K. and P. Bellinger. 1980. The Collembola of North America north of the Rio Grande. Part 2. Families Onychiuridae and Isotomidae. Grinnell College, Grinnell. Iowa. Dallai, R. 1969. Ricerche sui Collemboli. V. L'Isola di Montecristo. Redia 51:229-250. Gisin, H. 1943. Okologie und Lebensgememschaften der Collembolen im schweizeris­chen Lebensgebiet. Rev. Suisse Zool. 50:131-224. 1960. Collembolenfauna Europas. Mus. Hist. Natur., Geneva. Hammer, M. 1938. The zoology of east Greenland Collemboles. Mood. Gronland, Kobenhaven 121:1-42. Hazelton, M. and E. A. Glennie. 1953. Cave fauna and flora. Pp. 247-283. In: C. D. H. Collingford [00.]. British caving. Rutledge and Kegan, London. 7Bernard and Snider: Cryptopygus Bipunctatus (Collembola: Isotomidae) in NorthPublished by ValpoScholar, 1994156 THE GREAT LAKES ENTOMOlOGIST Vol. 27, No.3 Massoud, Z. andE. H. Rapoport. 1968. Collemboles Isotomidesd'Ameriquedu Sudetde I'Antarctique. BioI. Amer. Austr. 4:307-337. Mills, H. B. 1939. Remarks on the geographical distribution of North American Collem· bola. Bull. Brooklyn Entomol. Soc. 34:158-161. Salmon, J. T. 1964. An index to the Collembola. Vol. 1. Royal Soc. N. Z' Bull. 7Stach, J. 1947. The apterygotan fauna of Poland in relation to he world-fauna of this group of insects. Family: lsotomidae. Polish Acad Sci. Lett., Krakow. Willem, V. 1901. Les Collemboles recuellis par I'expedition antarctique beige. Ann. Soc. Entomol. Belg. 45:260-262. 8The Great Lakes Entomologist, Vol. 27, No. 3 [1994], Art. 4https://scholar.valpo.edu/tgle/vol27/iss3/4

\u3ci\u3eCryptopygus Bipunctatus\u3c/i\u3e (Collembola: Isotomidae) in North America, and \u3ci\u3eC. Posteroculatus\u3c/i\u3e N. Comb.

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\u3ci\u3eCryptopygus Bipunctatus\u3c/i\u3e (Collembola: Isotomidae) in North America, and \u3ci\u3eC. Posteroculatus\u3c/i\u3e N. Comb.

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