Leptanilla najaphalla, Griebenow, 2024

Griebenow, Zachary, 2024, Systematic revision of the ant subfamily Leptanillinae (Hymenoptera, Formicidae), ZooKeys 1189, pp. 83-184 : 83

Leptanilla najaphalla sp. nov.

Figs 13A-C , 14A-D , 15 , 16

Type material.

Holotype. Malaysia - Sabah • 1 male; Sipitang Dist., Mendolong; 4.917°N, 115.767°E (estimated from Google Earth to nearest minute); 27 Apr. 1988; S. Adebratt leg.; A1L; CASENT0106427 (MZLU00174197); MZLU. Paratypes. 5 male; same locality as for preceding; 16 Apr. 1988; S. Adebratt leg.; A1L; CASENT0106416 (MZLU00174186), CASENT0106417 (MZLU00174187), CASENT0106438 (MZLU00174208), CASENT0106444 (MZLU00174214), CASENT0106457 (MZLU00174227); MZLU • 5 male; same locality as for preceding; 19 Apr. 1988; S. Adebratt leg.; W5L; CASENT0106421, CASENT0106432, CASENT0106433, CASENT0106449, CASENT0106450; UCDC • 2 male; same locality as for preceding; 7 Apr. 1988; S. Adebratt leg.; A1L; CASENT0106435 (MZLU00174205), CASENT0106437 (MZLU00174207); MZLU • 1 male; same locality as for preceding; 4 May 1988; S. Adebratt leg.; T4/R; CASENT0106412; MCZC • 2 male; same locality as for preceding; 5 May 1988; S. Adebratt leg.; A1L; CASENT0106418, CASENT0106453; MCZC • 3 male; MALAYSIA, Sabah: same locality as for preceding; 13 May 1988; T4/R; CASENT0106414, CASENT0106415, CASENT0106429; CAS.

Measurements (mm) and indices, male.

Holotype: HW = 0.29; HL = 0.35; SL = 0.14; LF2 = 0.05; LF2 = 0.05; EL = 0.16; EW = 0.16; WL = 0.80; MSW = 0.26; MSL = 0.48; PTW = N/A; PTL = N/A; PTH = 0.24; REL = 46; SI = 48; CI = 82; OI = 98; MSI = 54. Paratypes (n = 18): HW = 0.27-0.31; HL = 0.27-0.40; SL = 0.12-0.16; LF2 = 0.05-0.06; EL = 0.14-0.17; EW = 0.14-0.16; WL = 0.69-0.83; MSW = 0.22-0.27; MSL = 0.42-0.53; PTW = 0.15-0.18; PTL = 0.12-0.15; PTH = 0.23-0.28; REL = 40-57; SI = 45-55; CI = 74-103; OI = 82-103; MSI = 48-54; PI = 105-140.

Description.

Cranial outline quadrate. Occiput emarginate in full-face view. Frons produced into anterior shelf. Mandible articulated to gena; distinctly longer than broad. Mandalus large, covering most of anterodorsal mandibular surface. Maxillary palp 1-merous. Clypeus anteroposteriorly reduced, concealed by frontal shelf in full-face view. Anterior tentorial pits not discernible. Compound eyes somewhat longer than wide in profile view, or EW and EL subequal (OI = 82-102), posterior margin slightly emarginate, all other margins convex. Anteromedian ocellus and compound eyes not intersecting line drawn perpendicular to anteroposterior axis of cranium. Scape anteroposteriorly compressed, longer than wide (SL = 0.124-0.154), shorter than anteroposterior length of compound eye; pedicel short, subcylindrical, lateral margins parallel, length 0.5 that of scape; antennomere 3 short, subcylindrical, length less than that of pedicel or scape; flagellum submoniliform, not extending posterior to mesoscutellum if folded flat over mesosoma. Pronotum and mesoscutum posteriorly prolonged. In profile view anterodorsal pronotal face slightly convex, diagonal to craniocaudal axis at ~ 45° angle. Mesoscutal dorsum planar; mesoscutum longer than broad (MSI = 48-53). Antero-admedian signum absent. Notauli absent. Parapsidal signa present, not impressed. Mesoscutellum longer than tall, dorsum not lower than that of mesoscutum, posterodorsal mesoscutellar face convex, not posteriorly produced. Oblique mesopleural sulcus present, not intersecting metapectal-propodeal complex. Metapleuron indistinct. Metapleural gland absent. Propodeum convex in profile view, with distinct dorsal and posterior faces; areas of these faces subequal. Procoxa longer than meso- and metacoxa; procoxa without distal transverse carina. Protrochanters sphenoid in outline, distally truncate. Profemur markedly constricted at base, anteroposteriorly compressed, incrassate; acute distal flange on posterior surface present; arcuate medial carina absent. Protibia> 0.5 × length of profemur, not dorsoventrally compressed, without ventromedian carina; protibial comb present, length of processes decreasing distally; probasitarsal seta not hypertrophied. Meso- and metatibial spur formula 2b,2b. C, Sc+R+Rs, 2s-rs +R+4-6, Rf, Mf1, cu-a, and Cuf+1A tubular; M+Cu and 1A nebulous; all other venation absent. Cuf+1A spectral apically, not reaching anal margin. Costal infuscation present proximal to 2s-rs +R+4-6; C extending well beyond infuscation. Abdominal segment II anteroposteriorly compressed, slightly broader than long in dorsal view (PI = 105-133); dorsal node present, well-developed, without median excavation. Abdominal sternite II with process along posterior half of length, outline cuneiform in profile view, apex rounded. Presclerites of abdominal segments IV-VIII inconspicuous. Abdominal segments III-IX without tergosternal fusion ( Griebenow et al. in press). Abdominal tergites IV-VII each broader than preceding tergite in dorsal view, lateral margins diverging posteriorly; breadth of abdominal tergite VIII less than that of abdominal tergite VII in posterodorsal view. Abdominal sternite VIII anteroposteriorly compressed, not visible without dissection, posterior margin entire ( Griebenow et al. in press). Abdominal sternite IX with posteromedian fusion to gonocoxites ( Griebenow et al. in press); anteroposteriorly compressed along median axis, laterally expanded and lobate. Mulceators present, subcircular in cross-section, longer than anteroposterior length of gonocoxites. Gonocoxites bulbous, with complete dorsomedian and ventromedian fusion; apicoventral laminae present, subulate in outline. Gonostyli absent. Volsellae present, with complete proximomedian fusion, subcircular in cross-section; sclerotized medial carina present at volsellar apex, produced into pair of denticles, dorsal denticle shorter than ventral one. Penial sclerites not dorsoventrally compressed, basally recurved, proximal ¼ subcircular in cross-section, apical 1/3 with ventromedian carina; rounded platform proximad this median carina with outline elliptical; phallotreme subapical and ventral, recessed, not surrounded by vestiture of setae; lateral laminate flanges present. Most sclerites with vestiture of subdecumbent to appressed setae; elongated on posterior margins of abdominal tergites III-VIII, increasing in length posteriorly; anterior faces of mulceators with elongate suberect setae; ectal faces of volsellae with suberect to erect setae, genitalia otherwise bare. Cuticle bearing piligerous punctae; sculpture fatiscent distad and proximad phallotreme (Fig. 16 ).

Etymology.

The specific epithet derives from Naja ( Squamata : Elapidae ), the cobra, and - phalla, meaning penis. This refers to the florid facies of the penial sclerites, which recalls the threat display of these snakes: the dorsal curvature of the penial sclerites resembles the rearing posture, while the lateral laminae resemble the extended “hood” of the cobra. The specific epithet is feminine.

Remarks.

The males of L. najaphalla uniformly differ from the sympatric undescribed morphospecies Leptanilla zhg-my05, to which L. najaphalla is sister, in the outline of the apicolateral gonocoxital lamina and the proportions of the penial sclerites and volsellae to the gonocoxites.

The description of L. najaphalla only from male specimens is justified for the same reasons as provided for the description of L. bethyloides , also only from male specimens (see “Remarks” concerning L. bethyloides above): the clade to which this species belongs, heretofore referred to as the "Bornean morphospecies group", is known only from male specimens. Leptanilla najaphalla was included in the phylogenetic analyses of Griebenow (2020, 2021) under the provisional identifier Leptanilla zhg-my02, with the genitalia being the subject of detailed morphological study using micro-computed tomography ( Griebenow et al. in press) under that same provisional identifier.

Revised diagnosis and generic classification of Leptanillinae

Based upon total-evidence and phylogenomic inference (in preparation by the author) corroborated by previous studies ( Griebenow 2020, 2021), I here enact a revised classification of the Leptanillinae , reducing the number of genera to three. Summaries of character states that in combination differentiate major clades of the Leptanillinae from their relatives are provided below. These summary diagnoses are based upon all adult castes and larvae, when available. Apomorphies relative to the parent taxon are italicized; characters of uncertain polarity are marked with an asterisk.

Figures

Figure 13. Leptanilla najaphalla, holotype (CASENT 0106427), male A profile view B dorsal view C full-face view. Scale bars: 0.5 mm (A, B); 0.2 mm (C).

Figure 14. Male genitalia of Leptanilla najaphalla A profile view, apicolateral gonocoxital lamina outlined (CASENT 0106424) B penial apex, posteroventral view (CASENT 0106421) C penial sclerites and phallotreme, ventral view (CASENT 0106433) D volsellar apex, dorsal view (CASENT 0106421). Abbreviation: pht = phallotreme. Scale bars: 0.1 mm (A, C, D); 0.2 mm (B).

Figure 15. Forewing of Leptanilla najaphalla (CASENT 0106419), male. Scale bar: 0.5 mm.

Figure 16. Phallotreme of Leptanilla najaphalla (CASENT 0106433). Scale bar: 0.5 mm.