Schizonyxhelea Clastrier, 1984

Borkent, Art, 2014, The Pupae of the Biting Midges of the World (Diptera: Ceratopogonidae), With a Generic Key and Analysis of the Phylogenetic Relationships Between Genera, Zootaxa 3879 (1), pp. 1-327 : 64-66

Schizonyxhelea Clastrier

( Figs. 11H , 20E–F , 25C , 29T , 36C , 44L–M , 49C , 60B , 74F–G )

DIAGNOSIS: Only pupa of Ceratopogonidae with the terminal process with a posterior row of thick spines and no other thick spicules present ( Fig. 74G ); also unique in the thoracic D-1-T much more stout than the other dorsal seta ( Fig. 29T ).

DESCRIPTION: Habitus as in Fig. 11H . Total length = 1.19–2.16 mm. Without larval exuviae retained on abdomen. Exuviae with flagellum appressed against lateral margin of face (as in Fig. 15D ). Ecdysial tear around base of antenna (as in Figs. 15D , 79E ); along prothoracic extension. Head: Dorsal apotome ( Figs. 20E–F ), without ventral line of weakness, without dorsomedial tubercle, without central dome; dorsolateral cephalic sclerite (as in Fig. 13B ) separated from scutum by thin cuticle, separate from scutum upon emergence, each side separated medially by dorsal apotome in whole pupa; mouthparts ( Fig. 25C ) with mandible well-developed, lacinia absent; palpus extending posterior to posterolateral margin of labium; labium separated medially by labrum, hypopharynx; apex of antenna ( Fig. 36C ) posterior to posterior extent of midlength portion of midleg (portion lateral to mesosternum); sensilla: dorsal apotomals ( Figs. 20E–F )—1 moderately elongate seta, 1 campaniform sensillum; dorsolateral cephalic sclerite sensilla—1 seta, no campaniform sensillum; clypeal-labrals ( Fig. 25C )—2 minute setae; oculars ( Fig. 25C )—2 elongate setae. Thorax: Prothoracic extension ( Fig. 25C ) wide, well-developed, extending from palpus to antenna; mesonotum with short tubercles, extending posteromedially, completely dividing metathorax medially ( Fig. 49C ); respiratory organ ( Figs. 44L–M ) length/width = 4.92–7.08, elongate, slender, somewhat flattened dorsoventrally, with pores closely abutting at apex of respiratory organ, arranged in single row, with additional more basal pores, outer surface smooth, with moderately elongate pedicel, base with short posteromedial apodeme, membranous base of respiratory organ moderately elongate, tracheal tube straight to slightly curved along length, with spirals restricted to base, distally with plate; wing ( Fig. 36C ) without apical tubercle or angle, separated medially by fore-, midlegs; halter apex and hind leg (similar to Fig. 32L ) broadly abutting; halter apex just posterior to knob-like extension of tergite 2; legs ( Fig. 36C ) with lateral margin of foreleg near midlength of wing evenly curved; hind leg visible at lateral margin of wing (as in Fig. 32L ); with apex of foreleg moderately anterior to apex of midleg; apex of hind leg abutting apex of midleg laterally; sensilla: anteromedials—2 setae, 1 thicker than other; anterolaterals—3 setae; dorsal setae ( Fig. 29T )—D-1-T, D-2-T, D-4- T setae with D-1-T stouter than others, D-3-T campaniform sensillum, D-5-T absent, D-3-T posteromedial to D-4- T; supraalar 2—campaniform sensillum; metathoracics ( Fig. 49C )—1 seta, 2 campaniform sensilla; M-3-T near anterior margin of metathorax. Abdomen: without pigmentation pattern, segment 2 as wide or slightly wider than segment 3, segments with undivided, thin to thick setae, with slightly rounded to pointed, or serrate short tubercles, tergites or sternites entire, each without membranous disc; segment 9 ( Figs. 74F–G ) with two dorsomedial short tubercles, one anterior to other, terminal processes closely approximated basally, each projecting posterodorsolaterally, tapering to pointed apex, with posterior row of spines; sensilla: tergite 1 ( Fig. 49C ) with 3, 5 setae, 2–3 campaniform sensilla, including 1 lateral sensillum, 1 seta close, D-7-I situated posteriorly near D-8-I; segment 4 ( Fig. 60B )—D-2-IV, D-3-IV short setae on serrate tubercles; D-5-IV barely visible short seta (or perhaps a campaniform sensillum), D-8-IV, D-9-IV short seta; D-5-IV, D-4-IV, D-7-IV, D-8-IV, D-9-IV on short, serrate tubercles, posterior dorsal sensilla in transverse row, arranged medially to laterally: D-5-IV, D-4-IV, D-7-IV, D-8- IV; L-1-IV short seta, on pointed tubercle, well anterior of posterior lateral setae; L-2-IV, L-3-IV short setae, L-4- IV thick seta on serrate tubercles, V-5-IV, V-6-IV, V-7-IV moderately elongate setae on serrate tubercles; segment 8 without D-3-VIII, without L-1-VIII; segment 9 ( Figs. 74F–G )—with D-5-IX campaniform sensillum, D-6-IX possibly absent (not discernable).

DISTRIBUTION AND HABITAT: The genus Schizonyxhelea is known from nine species from the New World and Oriental Regions ( Borkent 2014, additions below). Schizonyxhelea bulla has been reared from mud from the margins of a bog, from the grassy margin of a marsh and from mud, pond weeds and Sphagnum ( Thomsen 1937, Wirth & Grogan 1981). Borkent (2000a) found a larva of S. forattinii in wet mud in a small seep which flowed into the outflow of a larger spring in Costa Rica.

TAXONOMIC DISCUSSION: This genus previously included only two Neotropical species ( Borkent 2014) ( Tables 2–3 ). In his description of the larva and pupa of S. forattinii, Borkent (2000a) pointed out the striking similarities especially between the pupae of Schizonyxhelea forattinii Wirth & Grogan and Stilobezzia bulla Thomsen. A number of these are here interpreted as synapomorphies of the genus (characters 24, 54, 76, 79).

Nearly all male Schizonyxhelea have a unique and distinctive transverse band of cuticle ventral to the parameres (at about midlength), that is clearly a synapomorphy of the genus. It is uncertain what this structure is, considering that it is likely that a very reduced set of more ventrally located small sclerites is homologous to the aedeagus of other Ceratopogonidae . The male of S. forattinii lacks the ventral transverse band of cuticle but does have a pair of broad extensions from the midlength of the gonocoxites which extend dorsally to the parameres and overlap medially. A further synapomorphy of all species examined here is the reduced set of small sclerites making up the aedeagus. Some other adult features may be synapomorphies ( Borkent 2000a ) but further study is needed.

Historically, the shape of the claws of female adults has been used as a primary character to identify and recognize genera. The females of the two species originally placed in Schizonyxhelea ( S. forattinii , S. guyana ) had equal claws on each leg, a single, bent spermatheca and reduced wing venation. The additional species recognized here have single claws on each leg (with a basal tooth) and are similar to those of Stilobezzia , with two welldeveloped spermathecae and wings with two radial cells. I have examined a female from Costa Rica which has a wing venation identical to those of S. forattinii and S. guyana but has single claws and two spermathecae. I have examined other, non-related, Stilobezzia with equal claws and the same variation occurs, for example, in Serromyia ( Borkent & Bissett 1990) and Alluaudomyia (pers. obs. unnamed species). Clearly, single or equal claws are variable within these genera and should be used with caution in distinguishing other genera.

On the basis of the distinctive male genitalia and pupal synapomorphies, this genus now includes:

Schizonyxhelea brevicostalis (Das Gupta & Wirth), 1968: 28 ( Stilobezzia ). Malaysia, new combination. Schizonyxhelea bulla (Thomsen), 1935: 289 ( Stilobezzia ). USA, new combination.

Schizonyxhelea caribe (Lane & Forattini), 1958: 208 ( Stilobezzia ). Panama, new combination.

Schizonyxhelea diminuta (Lane & Forattini), 1958: 209 ( Stilobezzia ). Panama, new combination.

Schizonyxhelea forattinii Wirth & Grogan, 1988: 81 . Brazil.

Schizonyxhelea guyana Clastrier, 1984: 2 . French Guiana.

Schizonyxhelea obscura (Lane & Forattini), 1958: 216 ( Stilobezzia ). Panama, new combination.

Schizonyxhelea panamensis (Lane & Forattini), 1958: 218 ( Stilobezzia ). Panama, new combination. Schizonyxhelea thomsenae (Wirth), 1953: 83 ( Stilobezzia ). USA, new combination.

Schizonyxhelea scutata (Lane & Forattini), 1961: 92 ( Stilobezzia ). Panama, new combination.

Harris (1981) described seven species of Stilobezzia from Australia. Her species 6 is a Schizonyxhelea , with its characteristic features (i.e. thoracic sensilla D-1-T short and stout, distribution of abdominal 4 sensilla with each on a serrate tubercle, posteromedial margin of terminal process with row of spines). I have also examined a reared series of an unnamed species from Laos and there are a number of unnamed species (based on adults) from Costa Rica. Clearly the genus is more diverse and broadly distributed than was previously recognized.

Wirth & Grogan (1981) described the pupa of S. bulla (as a Stilobezzia ) but did not describe or illustrate the posterior row of spines which are actually present on the terminal process. Borkent (2000a) missed CL-1-H and CL-2-H on the mouthparts of the pupa as well as D-9-IV on abdominal segment 4 (the single specimen was dirty). Stilobezzia insolita Das Gupta & Wirth from Malaysia is known only as a female but it has a reduced wing venation and an apically swollen and basally curved spermatheca, all similar to some Schizonyxhelea (e.g. S. forattinii ). However, until further study, this species remains in Stilobezzia .

MATERIAL EXAMINED: S. bulla : 1 pupal exuviae, Algonquin Park, Ontario, Canada, 8-VI-1960 (USNM); 1 pupal exuviae, Patuxent Rescue Center, Prince George’s County, Maryland, USA, 17-V-1976 (USNM); 2 pupal exuviae, as previous locality, 4-VI-1976 (USNM); 1 pupal exuviae, as previous locality (WLGC); 1 pupal exuviae, Allegany State Park, New York, USA, 28-V-1963 (WLGC); 2 pupal exuviae, McLean Reserve, Tompkins County, New York, USA, 18-VI-1963 (WLGC); 1 pupal exuviae, Bergen Swamp, Genesee County, New York, USA, 14- VI-1963 (WLGC); 2 pupal exuviae, Research Station Pond, Newcomb, New York, USA, 30-VI-1958 (NYSM); 1 pupal exuviae, Meadow Hole, E. Berne, New York, USA, 29-VI-1963 (NYSM); 1 pupal exuviae, Wet Meadow Hole, E. Berne, New York, USA, 24-VI-1963 (NYSM); 1 pupal exuviae, Mitchell’s Meadow Pool, E. Berne, New York, USA, 29-VII-1963 (NYSM); 1 pupal exuviae, Lake Jimmy, Tahawus, New York, USA, 24-VI-1959 (NYSM); 1 pupal exuviae, Mud Pond Outlet, Blue Mountain Lake, New York, USA, 8-VI-1959 (NYSM); 1 pupal exuviae, Sphagnum Bog, Blue Mountain Lake , New York, USA, 7-VI-1959 (NYSM); 1 pupal exuviae, Salmon River, Blue Mountain Lake, New York, USA, 8-VI-1959 (NYSM); 1 pupal exuviae, Beartown Mt. Bog, Virginia, 16-VIII-1977 (VPIC); 1 pupal exuviae, Flag Glade, Pocahontas County, Virginia, USA, 24-VI-1976 (VPIC); 1 pupal exuviae, Jefferson Nt. Forest, Little Meadows, Giles County, Virginia, USA, 6-IX-1976 (VPIC). S. forattinii : 1 pupal exuviae, 2 km NE Tarcoles, Costa Rica, 17-XII-1993 (reared from larva) (CNCI). S. sp.: 1 pupal exuviae, Moung Sayaboury, Sayaboury Province, Laos, 22-II-1967 (BPBM); 1 pupal exuviae, as previous locality, 19-II- 1967 (BPBM); 5 pupal exuviae, Ban Na Tak, Moung Sayaboury, Sayaboury Province, Laos, 9-XII-1967 (BPBM).

Figures

FIGURE 11. Habitus. A. Forcipomyia (Thyridomyia) rugosa, male, in dorsal view (from Chan & LeRoux 1970). B. Forcipomyia (Pterobosca) crinume, female, in ventral view (from Tokunaga 1932). C. Forcipomyia (Lasiohelea) rugosa, male, in dorsal view (from Saunders 1964). D. Atrichopogon hexastichus, male, in dorsal view (from Nielsen 1951). E. Atrichopogon wirthi, female, in dorsal view (from Chan & Linley 1988). F. Atrichopogon muelleri, sex unknown, in dorsal view, with larval exuviae on posterior of abdomen (from Szadziewski et al. 1997). G. Dasyhelea vericolor, sex unknown, in dorsal view (from Szadziewski et al. 1997). H. Schizonyxhelea bulla, sex unknown, in dorsal view (from Thomsen 1937).

FIGURE 13. Anterior portion of heads and thoraces, in anterior or anterodorsal view. A. Leptoconops kerteszi, ecdysial sutures of head enhanced to show position. B. Culicoides denticulatus. C. Ceratopogon nr. abstrusus. D. Brachypogon sp. (from 6 km E. Falkland, BC, Canada). E. Alluaudomyia bella, dorsal apotome absent. F. Clinohelea curriei. G. Pellucidomyia leei. H. Mallochohelea caudellii. I. Bezzia sp. (from Bolean Lake, BC, Canada).

FIGURE 15. Anterior portion of heads. A. Culicoides denticulatus, in anteroventral view. B. Ceratopogon nr. abstrusus, in anterior view. C. Brachypogon sp., in anterior view (from 6 km E. Falkland, BC, Canada). D. Stilobezzia antennalis, in ventral view, dorsal apotome not present. E. Allohelea japonica, in ventral view, dorsal apotome not present (distorted slide specimen). F. Atyphohelea macroneura, in ventral view, right side of head, dorsal apotome not present.

FIGURE 20. Dorsal apotomes, anterior view. A. Stilobezzia soror (from Mayer 1934c). B. Stilobezzia lutea (from Wirth & Grogan 1981). C. Stilobezzia antennalis (from Wirth & Grogan 1981). D. Stilobezzia pallidiventris (from Wirth & Grogan 1981). E. Schizonyxhelea forattinii (from Borkent 2000a). F. Schizonyxhelea bulla (from Wirth & Grogan 1981, modified). G. Serromyia sp.. H. Allohelea japonica. I. Monohelea obscura. J. Atyphohelea macroneura (from Borkent 1998). K. Parabezzia alexanderi male (from Grogan & Wirth 1977a, modified). L. Parabezzia alexanderi female (from Grogan & Wirth 1977a, modified). M. Clinohelea dryas (from Elson-Harris & Kettle 1986). N. Clinohelea tasmaniensis (from Elson-Harris & Kettle 1986). O. Heteromyia wokei (from Wirth & Grogan 1977, modified). P. Pellucidomyia leei (from Elson-Harris & Kettle 1986).

FIGURE 25. Posterior portion of heads, in ventral view. A. Stilobezzia antennalis. B. Stilobezzia rabelloi (from Borkent & Craig 2001). C. Schizonyxhelea bulla. D. Serromyia sp.. E. Allohelea japonica. F. Monohelea obscura (reconstructed from distorted specimen). G. Atyphohelea macroneura. H. Parabezzia huberti.

FIGURE 29. Dorsal setae from left side of thoraces. A. Austroconops mcmillani. B. Leptoconops kerteszi. C. Leptoconops linleyi. D. Forcipomyia (Euprojoannisia) sp. (from Peru). E. Forcipomyia (Forcipomyia) bipunctata. F. Forcipomyia (Phytohelea) n. sp. nr. antiguensis. G. Atrichopogon sp. (from Lake Opinicon, Ontario, Canada). H. Dasyhelea paracincta. I. Dasyhelea atlantis. J. Dasyhelea pseudoincisurata. K. Culicoides haematopotus. L. Culicoides phlebotomus. M. Paradasyhelea albipunctata. N. Ceratopogon boomerangus. O. Brachypogon sp. (from 6 km E. Falkland, BC, Canada). P. Alluaudomyia needhami. Q. Baeodasymyia christopheri (from Borkent & Craig 1999). R. Austrohelea campbellensis. S. Stilobezzia antennalis. T. Schizonyxhelea forattinii (from Borkent 2000a).

FIGURE 32. Cephalothoraces and abdominal segments 1–3, in lateral view. A. Austroconops mcmillani. B. Leptoconops linleyi. C. Forcipomyia (Phytohelea) sp. (Florida, USA). D. Atrichopogon sp. (from 6.5 km NW Enderby, BC, Canada). E. Dasyhelea sp., in anteroventral view (Herman Lake, 4 km SE Eagle Bay, BC, Canada). F. Dasyhelea oppresa. G. Culicoides denticulatus. H. Ceratopogon nr. abstrusus. I. Brachypogon sp. (from 6 km E. Falkland, BC, Canada). J. Alluaudomyia bella. K. Baeodasymyia michaeli. L. Stilobezzia antennalis.

FIGURE 36. Legs, wings and apices of the antennae, in ventral view. A. Stilobezzia antennalis. B. Stilobezzia lutea. C. Schizonyxhelea forattinii. D. Serromyia sp.. E. Allohelea japonica (reconstructed from distorted specimen). F. Monohelea obscura (reconstructed from distorted specimen).

FIGURE 44. Respiratory organs, in dorsal view, pattern on tracheal tubes shown only in some. A. Alluaudomyia latipennis (from Debenham 1971). B. Alluaudomyia footei (from Wirth & Grogan 1981). C. Baeodasymyia christopheri (from Borkent & Craig 1999). D. Austrohelea campbellensis. E. Stilobezzia antennalis (from Wirth & Grogan 1981, modified). F. Stilobezzia glauca (from Wirth & Grogan 1981). G. Stilobezzia ochracea (from Kettle & Lawson 1952). H. Stilobezzia diversa (from Wirth & Grogan 1981). I. Stilobezzia rabelloi (from Borkent & Craig 2001). J. Stilobezzia navaiae (from Wirth & Grogan 1981). K. Stilobezzia lutea (from Wirth & Grogan 1981). L. Schizonyxhelea bulla (from Wirth & Grogan 1981, as a Stilobezzia). M. Schizonyxhelea forattinii (from Borkent 2000a). N. Serromyia femorata (from Kettle & Lawson 1952). O. Allohelea japonica. P.Monohelea hirsuta (from Wirth & Grogan 1981, modified). Q. Atyphohelea macroneura (from Borkent 1998). R. Parabezzia alexanderi (from Grogan & Wirth 1977a). S. Parabezzia huberti (from Grogan & Wirth 1977a). T. Echinohelea lanei (from Wirth 1994b).

FIGURE 49. Metathoraces and tergites 1, in dorsal view. A. Austrohelea campbellensis. B. Stilobezzia antennalis. C. Schizonyxhelea forattinii. D. Serromyia sp.. E. Allohelea japonica. F. Monohelea obscura.

FIGURE 60. Abdominal segments four, in dorsal and ventral view (shagreen not shown). A. Stilobezzia rabelloi (from Borkent & Craig 2001). B. Schizonyxhelea forattinii (from Borkent 2000a, modified). C. Serromyia sp.

FIGURE 74. Abdominal segments 9. A. Baeodasymyia michaeli, female, in dorsal view (modified from Borkent & Craig 1999). B. Austrohelea campbellensis, female, in dorsal and ventral view (reconstructed from distorted specimen, shagreen not shown). C. Stilobezzia lutea, male, in dorsal and ventral view (from Wirth & Grogan 1981). D. Stilobezzia lutea, female, in dorsal and ventral view (from Wirth & Grogan 1981). E. Stilobezzia rabelloi, male, in ventral view (from Borkent & Craig 2001). F. Schizonyxhelea bulla, female, in dorsal and ventral view (from Wirth & Grogan 1981). G. Schizonyxhelea forattinii, female, in ventral view (from Borkent 2000a). H. Serromyia sp., female (in dorsal and ventral view (reconstructed from distorted specimen, shagreen not shown). I. Allohelea japonica, female, in dorsal and ventral view (shagreen not shown). J. Monohelea obscura, male, in dorsal and ventral view (reconstructed from distorted specimen, shagreen not shown). K. Atyphohelea macroneura, female, in dorsal view (from Borkent 1998). L. Parabezzia huberti, male, in ventral view (from Grogan & Wirth 1977a).

FIGURE 79. Evolution of ecdysial sutures and splits in pupal exuviae of Ceratopogonidae, head and anterior portion of thorax in ventral view. Numbers refer to character states of characters 2 and 8 in text. Red indicates ecdysial splits. A. Leptoconopinae. B. Forcipomyiinae. C. Dasyheleinae. D. Most Ceratopogonini. E. Most Ceratopogonini, Clinohelea. F. Allohelea, Atyphohelea, Parabezzia. G. Heteromyia, Pellucidomyia, Hebetula. H. most Sphaeromiini s. lat., most Palpomyiini, Paryphoconus; some Bezzia are nearly completed fused (as in Fig. 79I), with only the dorsal apotome separate, along with an ecdysial split along the base of the antenna and the dorsal thoracic split. I. Jenkinshelea, Macropeza, Mallochohelea, Probezzia, Neobezzia.