Deltocephalus (Laevicephalus) concinnus var. incisurus DeLong, 1926 (here designated)

The name is derived from the Greek βορέας (north) and λίμνη (marsh), describing the habitat of the type species. The gender is masculine.

Separated from other genera of Paralimnini by the following combination of characters: male subgenital plates with uniseriate macrosetae, plates as long as pygofer and tapering to a narrow rounded apex; pygofer with a process on postero-ventral margin, process nearly straight; segment X about as long as wide, broadly scerotized laterally and narrowly sclerotized dorsally; connective linear and elongate with arms fused in a stem which is about as broad as long (connective loop-shaped sensu Emeljanov (1999)); aedeagus broad and dorsoventrally flattened with subapical ventral gonopore and one pair of pre-apical processes; frontoclypeus and pronotum with longitudinal stripes; wings macropterous, fore wing with outer anteapical cell short and closed by distal fusion of veins R2+3 and R4+5 or absent.

Small leafhoppers with typical Paralimnini structure. Colour generally stramineous, head and pronotum with longitudinal stripes, wing with brown infuscation around cell borders (Figs 2–5).

Figures 2–14. 

Boreolimnus incisurus 2 dorsal habitus 3 lateral habitus 4 abdomen ventral, female 5 face 6 male pygofer, dorsal 7 male pygofer, lateral 8 male subgenital plate, styles, connective, dorsal 9 aedeagus, caudal 10 aedeagus, lateral 11 female genital capsule, ventral 12 female sternite VII, ventral 13 first valvifer, lateral, with enlargement 14 second valvifers, lateral, with enlargement.

Head with crown bluntly angled, medial length about 1.5× width between eyes (Fig. 2). Crown glabrous with fine striations on basal 2/3, distal 1/3 of crown and face shagreen. Lateral frontal sutures terminating lateral of ocelli, ocelli about 2× their own diameter from eye (Fig. 5). Mesal margin of eye notched. Anteclypeus with margins nearly straight, slightly tapered pre-apically. Lorum about 3/5 width of anteclypeus, well separated from genal margin. Antennae about as long as head width.

Pronotum slightly narrower than width of head across eyes, slightly longer than medial length of head. Fore femur with AM1 near ventral margin, row IC with a few fine setae, row AV consisting of a few, widely spaced, very short setae. Fore tibia with 1 AD and 4 PD macrosetae. Hind femur with 2+2+1 macrosetae. First hind tarsomere with two rows of plantar setae, four apical platellae between a pair of normal setae. Fore wing usually with three closed anteapical cells; outer anteapical cell short and closed by distal fusion of R2+3 and R4+5 or occasionally absent.

Male abdomen with apodemes on sternite II about twice as long as wide, apical half transparent, strongly curved dorsally. Pygofer about as long as wide, with a triangular distal lobe and a sclerotized process from posteroventral corner; with a patch of long macrosetae posterodorsally and shorter fine macrosetae scattered ventrally (Figs 6, 7). Segment X about as long as wide, heavily sclerotized laterally, the sclerotized portions narrowly connected posteriorly and separated by a V-shaped unsclerotized area medially. Valve parabolic. Subgenital plates as long as pygofer, subtriangular, with a narrowly rounded apex, bearing a single row of macrosetae (Fig. 8). Connective with arms nearly parallel, slightly bowed outwards towards anterior end and fused anteriorly, stem broadened apically, wider than arms and about as long as broad. Style apophysis with lateral lobe prominent, medial lobe with rounded teeth ventrally. Aedeagus dorsoventrally flattened with subapical ventral gonopore and one pair of pre-apical processes (Figs 9, 10).

Female pygofer with moderate length macrosetae (Fig. 11). Ovipositor not projecting beyond pygofer. Gonoplac without macrosetae. First valvula slightly concave; sculpture imbricate dorsally and strigate ventrally (Fig. 13). Second valvulae evenly tapered distally, with fine irregular dorsal teeth (Fig. 14).

Boreolimnus runs to Latalus in the keys of both Oman (1949) and Beirne (1956), but can be distinguished by several characters (alternative states in parentheses): outer anteapical cell reduced and closed by fusion of R2+3 and R4+5 (well developed and closed by crossvein s), connective narrow and nearly linear, with the posterior plate the widest part (connective broad and widest across the arms), aedeagus dorsoventrally flattened (aedeagus tubular, not flattened), frontoclypeus with longitudinal stripes (frontoclypeus with pale transverse markings separating darker areas). In Emeljanov (1999), it keys to couplet 300/307 but does not match either alternative well. In Ossiannilsson (1983) it keys best to Lebradea, from which is differs in the following characters: segment X about as long as wide (segment X about twice as long as wide), connective with arms connected posteriorly by a broad and long plate-like stem (connective with arms connected by a narrow bar-like stem posteriorly), stramineous with longitudinal stripes on frontoclypeus and pronotum and brown infuscation around wing cells (mostly bright yellow with black areas, no longitudinal stripes or infuscation on wing).

Males 3.1–3.4 mm. Females 3.2–3.6 mm.

Colour mostly pale straw to light yellow, with two longitudinal stripes on crown and four longitudinal stripes on pronotum in a deeper yellow colour usually apparent. Palest specimens with dark colour restricted to basal tergites and spots at bases of leg macrosetae. Darker specimens may have light to dark brown markings medially on frontoclypeus (interrupted laterally by pale horizontal lines), in antennal pits, on anepisternum, medially on abdominal tergites, on base of sternite II and laterally on all sternites, and on pygofer. Fore wing milky white with brown infuscation around border of some cells.

Male pygofer process short, originating on postero-ventral margin and extending slightly dorsally. Process typically with two small teeth on ventral margin. Subgenital plates bearing a single row of approximately eight macrosetae laterally. Style with lateral lobe of apophysis quadrately rounded, medial lobe of apophysis sickle-shaped, with four or five widely spaced, rounded teeth ventrally. Aedeagus in lateral view dorsoventrally flattened, strongly curved anterodorsally, extending slightly dorsally of atrium. Atrium in posterior view with deep and broad dorsal excavation; shaft in posterior view broad, narrowing preapically, with a single pair of lateral processes just before apex, terminating in a round plate above gonopore.

Female sternite VII rectangular, posterior margin with slight, rounded projections medially and laterally and gently convex in between, medial projection with a small emargination surrounded by a dark area (Fig. 12). Gonoplac mostly dark. Base of first valvula in ventral view truncate (Fig. 11).

Holotype of Deltocephalus incisurus DeLong. USA • ♀; Wisconsin, Ladysmith; 9 Aug. 1916; D.M. DeLong leg.; OSUC, OSUC 870278.

Holotype of Latalus hultus Beirne. Canada • ♂; Manitoba, Birch River; 13 Aug. 1930; R.H. Handford leg.; CNC, CNC1197446.

Holotype of Cribrus micmac Hamilton. Canada • ♀; Nova Scotia, Cape Breton Highlands National Park, Paquet’s Lake; 27 Aug. 1983; M. Sharkey leg.; CNC, CNC#HEM403381.

Canada – Alberta • 1 ♂; Beaverlodge; 1 Aug. 1961; A.R. Brooks leg.; CNC • 1 ♀; Grande Prairie; 25 Jul. 1961; A.R. Brooks leg.; CNC • 1 ♂; High Prairie; 16 Jul. 1961; A.R. Brooks leg.; CNC • 20 ♂, 12 ♀, 1 (no abdomen); same collection data as previous; 17 Jul. 1961; CNC • 18 ♂, 16 ♀, 2 (intersex); same collection data as previous; 22 Jul. 1961; CNC • 1 ♂; same collection data as previous; 25 Jul. 1961; CNC • 1 ♀; same collection data as previous; 26 Jul. 1961; CNC • 3 ♂, 1 ♀; Peace River; 12 Jul. 1961; A.R. Brooks leg.; CNC • 1 ♂, 7 ♀, 1 (intersex); Valleyview; 10 Aug. 1961; A.R. Brooks leg; CNC. – New Brunswick • 1; Kouchibouguac National Park; 16 Aug. 1977; S.J. Miller leg.; CNC. – Ontario • 1 ♀; 10 mi E Nipigon; 12 Aug. 1975; K.G.A. Hamilton leg.; CNC • 1 ♀; 4 mi S Beardmore; 12 Aug. 1975; K.G.A. Hamilton leg.; from Calamagrostis canadensis; CNC • 28 (unmounted specimens in a capsule); Sault Sainte Marie; 10 Aug. 1975; K.G.A. Hamilton leg.; from Carex sp.; CNC. – Saskatchewan • 4 ♀; Candle Lake; 19 Aug. 1959; A. & J. Brooks leg.; CNC. – Manitoba • 1 ♀; The Pas; 30 Aug. 1959; A. & J. Brooks leg.; CNC.

The holotype of Deltocephalus incisurus (Figs 15–18) was not previously labelled as such in the OSUC collection. The red “paratype” label and blue “incisurus” label were both probably added by later workers. However, it seems clear this is the holotype, as it matches the locality data, description, and illustrations in DeLong (1926). This specimen is also presumably one of the two syntypes of Deltocephalus concinnus Sanders & DeLong, based on the labels which match the data in the original description and the fact that no other potential syntypes could be located in DeLong’s collection (L. Musetti pers. comm. 2022). As I am designating the other syntype as lectotype of D. concinnus (see below), this specimen becomes a paralectotype of the latter species.

Figures 15–24. 

Boreolimnus incisurus and synonyms, primary types 15–18 Deltocephalus concinnus var. incisurus DeLong, holotype 15 dorsal habitus 16 lateral habitus 17 abdomen, ventral 18 labels 19–21 Latalus hultus Beirne, holotype 19 lateral habitus 20 labels 21 dorsal habitus 22–24 Cribrus micmac Hamilton, holotype 22 lateral habitus 23 labels 24 dorsal habitus.

The holotype of Latalus hultus (Figs 19–21) has been dissected, and matches other males of this species. The original description (Beirne 1954a) did not include collection details for the holotype; these were provided in an erratum (Beirne 1954b). The latter also mentions a paratype which could not be located in the CNC; its whereabouts are unknown.

The holotype of Cribrus micmac (Figs 22–24) has the fore wings reaching about the middle of the genital segment. The hind wing length is difficult to determine precisely as the wings are greasy and stuck together, but they appear to be about as long as the fore wings. In all other examined females, both wings exceed the apex of the genital segment although there is some variation in how far they exceed the apex. The holotype appears to have been parasitized, with a dark mass resembling a dryinid larval sac projecting between the first and second thoracic segments; this could have caused abnormal development of the wings. The seventh sternite also has a shallower medial emargination compared to other females, but again this may represent abnormal development due to parasitization. Otherwise, the holotype matches other examined females in structure and colour, and the small COI fragment available for the specimen (GenBank accession PP719690, 137 bp) is 100% identical to the sequence from B. incisurus included in the phylogenetic analysis.

Females of this species can be separated from Cribrus and other Nearctic Paralimnini with longitudinal stripes on the head and pronotum based on the distinctly infuscated cell borders of the fore wing, reduction of the outer anteapical cell, sternite VII with slightly projecting posterior corners and a small darkened emargination medially, and dark gonoplacs.

Recorded from Alberta to Nova Scotia, south to Wisconsin (Fig. 25). Locations largely fall within the southern boreal forest or transition zones.

Figure 25. 

Map of localities for Boreolimnus incisurus (black dots) and Cribrus concinnus (white dots). The half-filled dot is Ladysmith, Wisconsin, type locality for both species and the only known co-occurrence.

Associated with graminoids in northern wetlands, although the specific host is unclear. The type specimen was collected from “grasses on the margin of a tamarack bog” (DeLong 1926). Beamer’s collection from Cowan, MB was probably collected from grasses along the margin of a lake (based on Beamer’s collection notes for this locality, as quoted by Whitcomb and Hicks 1988: 323). One specimen from near Beardmore, ON was collected from Calamagrostis canadensis, while a large series from Sault Ste. Marie, ON was collected from Carex sp. All three Ontario localities were wetlands with Calamagrostis canadensis as a dominant species (K.G.A. Hamilton field notes, unpublished) and this common wetland grass is a potential candidate for the host plant, but further fieldwork is needed.

Laevicephalus shingwauki Beamer & Tuthill, 1934, by original designation (Oman 1949: 166).

Separated from other genera of Paralimnini by the following combination of characters: male subgenital plates with uniseriate macrosetae, plates truncate and shorter than pygofer; pygofer without processes; pygofer with a prominent pair of dorsal spots; connective linear with posterior stem about as long as wide (connective loop-shaped sensu Emeljanov (1999)); aedeagus with swollen atrium, short shaft with apical gonopore and one pair of apical processes; frontoclypeus and pronotum with longitudinal stripes; wings usually brachypterous, fore wing with three closed anteapical cells.

Small leafhoppers with typical Paralimnini structure. Colour generally stramineous, head and pronotum with longitudinal stripes, wing with indistinct brown infuscation around cell borders (Figs 26–31).

Head with crown bluntly angled, medial length about equal to width between eyes (Figs 26, 27). Crown glabrous at base, margin and face shagreen. Lateral frontal sutures terminating just ventral of ocelli, ocelli about their own diameter distant from eye (Fig. 30). Mesal margin of eye notched. Anteclypeus with margins slightly convex, distal third distinctly tapered. Lorum about half width of anteclypeus, well separated from genal margin. Antennae about as long as head width.

Figures 26–40. 

Cribrus concinnus 26 dorsal habitus, male 27 dorsal habitus, female 28 abdomen ventral, female 29 lateral habitus, male 30 face 31 lateral habitus, female 32 male pygofer, dorsal 33 male pygofer, lateral 34 male subgenital plate, styles, connective, dorsal 35 aedeagus, caudal 36 aedeagus, lateral 37 female genital capsule, ventral 38 first valvifer, lateral, with enlargement 39 second valvifers, lateral, with enlargement 40 female sternite VII, ventral.

Pronotum slightly narrower than width of head across eyes, about as long as medial length of head. Fore femur with AM1 near ventral margin, row IC with a few fine setae, row AV consisting of a few, widely spaced, very short setae. Fore tibia with 1 AD and 4 PD macrosetae. Hind femur with 2+2+1 macrosetae. First hind tarsomere with two rows of plantar setae, four apical platellae between a pair of longer normal setae. Fore wing with three closed anteapical cells, although venation may be distorted due to brachyptery.

Male abdomen with apodemes on sternite II poorly developed, shorter than width. Pygofer about twice as long as wide, with a patch of long macrosetae posterodorsally and a few small macrosetae scattered ventrally (Figs 32, 33). Pygofer dorsally with a pair of heavily sclerotized spots basal to segment X. Segment X about as long as wide, completely sclerotized dorsally and laterally. Valve parabolic. Subgenital plates truncate, shorter than pygofer, bearing a single row of macrosetae laterally (Fig. 34). Connective with arms fused anteriorly, tapered towards posterior end, stem abruptly broadened apically, wider than arms. Style apophysis with lateral lobe weakly developed, medial lobe with corrugated sculpture but no distinct teeth. Aedeagus with swollen atrium, shaft very short with apical gonopore, with one pair of apical processes (Figs 35, 36).

Female pygofer with moderate length macrosetae (Fig. 37). Ovipositor not projecting beyond pygofer. Gonoplac without macrosetae. First valvula slightly concave; sculpture imbricate dorsally and strigate ventrally (Fig. 38). Second valvulae evenly tapered distally, with rounded teeth decreasing in size distally (Fig. 39).

Males 2.5–2.8 mm. Females 3.3–3.6 mm.

Colour mostly light yellow, with two light brown longitudinal stripes on crown and four longitudinal stripes on pronotum. Legs with dark spots at bases of macrosetae. Abdominal tergites with four brown to black longitudinal stripes usually apparent. Abdominal sternites may have lateral brown markings. Fore wing pale brown with indistinct darker brown infuscation around border of cells. Wing length variable in females, from fully macropterous to brachypterous with fore wing reaching apex of tergite VI and hind wing reaching apex of tergite II. Males brachypterous with fore wing reaching base to midpoint of pygofer and hind wing reaching apex of tergite II to III.

Subgenital plates bearing a single row of approximately seven macrosetae laterally. Style with medial lobe of apophysis finger-shaped. Aedeagus with long apical processes curving toward base, sculptured with complex ridges.

Female sternite VII rectangular, posterior corners rounded, posterior margin straight to moderately convex, may have slight projections medially and laterally (Fig. 40). Gonoplac pale. Base of first valvula in ventral view elongate (Fig. 37).

Lectotype of Deltocephalus concinnus Sanders & DeLong (here designated). USA • ♀; Wisconsin, Ladysmith; 9 Aug. 1916; D.M. DeLong leg.; OSUC, OSUC 0171752.

Holotype of Deltocephalus plagus Ball & DeLong. USA • ♀ (specimen missing from point, not examined); Wisconsin, Madison; 21 Sep. 1917; E.D. Ball leg.; USNM.

Holotype of Laevicephalus shingwauki Beamer & Tuthill. USA • ♂ (apparently lost, not examined); Minnesota, Aitkin; 25 Aug. 1933; P.B. Lawson leg.; SEMC.

USA – Illinois • 1 ♂, 3 ♀; 3 mi W Kankakee; 25 Aug. 1980; K.G.A. Hamilton leg.; CNC • 24 ♀; Fox Lake; 26 Jun. 1935; DeLong & Ross leg.; INHS • 2 ♂, 1 ♀; Fox Lake; 6 Aug. 1935; DeLong & Ross leg.; INHS • 3 ♀; Fox Lake; 26 Jun. 1936; Frison & DeLong leg.; INHS • 8 ♂, 7 ♀, 2 nymphs, approximately 20 unmounted specimens in a capsule; Iroquois Co., 7 mi NE Beaverville; 25 Sep. 1962; Ross & Ross leg.; from Calamagrostis canadensis; GL 177; CNC • 1 ♀; Zion; 16 Jun. 1954; Sanderson & Moore leg.; CNC. – Wisconsin • 1 ♂; Juneau Co., 6 mi NE Mather; 17 Jul. 1963; Smith & Stannard leg.; GL 654; CNC • 8 ♀; Wood Co.; 16 Jul. 1963; Stannard & Smith leg.; GL 666; CNC.

All males examined are brachypterous and clearly belong to a single species with distinctive genitalia. Females differing in wing length were previously treated as distinct species (e.g. DeLong 1948), but other structural features and colour pattern are consistent among specimens with different length wings. The examined series from Fox Lake, Illinois, collected on 30 June 1935, includes 23 brachypterous females with fore wing reaching the apex of tergites VI to VII and hind wing reaching the apex of tergites II to IV (all identified by D. DeLong as “Laevicephalus shingwauki”) (Figs 41, 42) and one macropterous female with fore and hind wings both exceeding the tip of the abdomen (identified by D. DeLong as “Laevicephalus concinnus”) (Fig. 43). The specimens are otherwise inseparable, and the best explanation for the wing length variation among females is the presence of a rare macropterous morph within a single species. Synonymies in the genus are complicated by the apparent loss of the type material of C. plagus and C. shingwauki, but the available evidence suggests both be treated as junior synonyms of C. concinnus. With the synonymies proposed here, Cribrus becomes a monotypic genus including only C. concinnus.

Figures 41–43. 

Cribrus concinnus, dorsal habitus. Females collected at Fox Lake, Illinois, 30 June 1935. Horizontal lines mark apex of hind wing 41 shorter-winged brachypter, right forewing missing 42 longer-winged brachypter 43 macropter.

Sanders and DeLong (1917) described D. concinnus from two female syntypes from the same locality. One of these was apparently later designated as the holotype of D. concinnus var. incisurus as discussed above. There is no published lectotype designation for D. concinnus, and so I here designate the other syntype (Figs 44–47) as lectotype to stabilize the application of the name. This appears to be the specimen illustrated under this name by Sanders and DeLong (1917) and DeLong (1926). The specimen was labelled as “holotype” in DeLong’s collection in OSUC. However, this label was probably added later by another worker (L. Musetti pers. comm. 2022) and is incorrect, as no holotype was originally designated. The lectotype is a macropterous specimen, but it is otherwise indistinguishable from other female specimens of the species.

Figures 44–47. 

Deltocephalus concinnus Sanders & DeLong, lectotype 44 dorsal habitus 45 lateral habitus 46 abdomen, ventral 47 labels.

The holotype of D. plagus is missing from the point, with only a leg remaining (S. McKamey pers. comm. 2022). The original description and illustrations are both good matches to brachypterous females of this species. Oman (1949) suggested D. plagus was probably a synonym of C. shingwauki, although he did not formally synonymize them.

The holotype and a male paratype of Laevicephalus shingwauki are stated in the original description to be deposited in the SEMC, but they can not be located there now (R. Osborn pers. comm. 2024). Beamer and Tuthill (1934) separated their species from C. concinnus based on the smaller size, shorter wings, and abdominal colouration, although they speculated it might actually be the male of the former. Ross and Hamilton (1972) later also suggested that C. concinnus was “close to if not the same species as C. shingwauki.” Although the internal genitalia of the type series were not described, the description of the external characters and illustration of the external genitalia are a clear match to the present concept. The differences in size and abdominal colouration mentioned by Beamer and Tuthill (1934) both represent sexual dimorphism within the species.

Females of this species can be separated from Boreolimnus and other Nearctic Paralimnini with longitudinal stripes on the head and pronotum based on the longitudinal dorsal stripes on the abdomen, outer anteapical cell well developed and closed by crossvein s, sternite VII entirely pale with rounded posterior corners and without medial emargination, and pale gonoplacs.

Found in the midwestern United States (Minnesota to Indiana), around the eastern margin of the tallgrass prairie region (Fig. 25).

Associated with Calamagrostis, usually in mesic to wet prairie or wetlands (DeLong 1948; Panzer et al. 2003; J. Bess pers. comm.; examined specimens).