Nilomantis edmundsi Roy, 1975

Sydney K. Brannoch & Gavin J. Svenson, 2016, Leveraging female genitalic characters for generic and species delimitation in Nilomantis Werner, 1907 and Ilomantis Giglio-Tos, 1915 (Mantodea, Nilomantinae), Insect Systematics & Evolution 47, pp. 209-244 : 238-240

publication ID	https://doi.org/ 10.1163/1876312X-47032141
DOI	https://doi.org/10.5281/zenodo.6066875
persistent identifier	https://treatment.plazi.org/id/4A09B002-343C-FFA2-FF88-FE1B65A2F9E0
treatment provided by	Plazi
scientific name	Nilomantis edmundsi Roy, 1975
status

Treatment

Nilomantis edmundsi Roy, 1975: 313 –316; Edmunds 1976: 6 –7, 34; Edmunds 1986: 41, 45; Ehrmann 2002: 242; Otte & Spearman 2005: 120 –121

Examined specimens

The list consists of 1 specimen. Ghana; 1♀, GSMC 001500, MN244 Secondary voucher, Genitalia No. 0 0 0 0 5 S. K. Brannoch.

Male genitalia description

An examination of the plates presented by Roy & Leston (1975) indicates that the anterior process (ap) is narrow. Apical process (paa) broad and recurved. Apophysis phalloide (L1) does not retain the apophysis; lobo membranoso (loa) lightly sclerotized and crenulated on the distal margin. Ventral sclerotization of the left phallomeric process (L4A) terminates in two lobes; processo distale (pda) largely rounded and well separated from a secondary lobe that is rounded and relatively smaller. Processo ventrale sclerificato (pva) and piastra ventrale (pia) sclerotized and more well defined than in N. floweri ; right arm (bm) pointed distally and lightly sclerotized.

Female genitalia description ( Figs 4 View Fig. 4 B, 6C,D)

Gonapophysis VIII (GA) slender, variably ciliated, slightly arcuate, and visibly curved from both the ventral (VH) and lateral (LH) perspectives; GA surfaced with fossettes. From VH, gonocoxa VIII (VF) internal margin narrow, rounded, lending VF an angular appearance; from LH, VF possesses a distinct knob-like projection that is directed dorsad. From VH, GA gently curves inward. From LH, GA obtusely curved ventrad; GA ventral margin features a rugose, sparsely ciliated medial outgrowth (MO), which projects posterior to the crest of the curve. GA external margin possesses a moderately sclerotized tubercle anterior to MO. From VH, apical lobe (AL) ovoid, pitted, distinctly lacking cilia across surface majority; from LH, AL thin, arched, pitted, and approximately pointed; no visible cilia observed. AL has a pronounced membrane that projects from the internal dorsal margin of the structure, forming a shallow pocket as the membrane merges with the dorsal margin of GA, lending AL the appearance of being bilobed or mitten-shaped. GA dorsal margin invaginated at the region that bends towards the ventral habitus. Gonapophysis IX (GP) relatively short, broadening at the site of the medial tine (MT) before narrowing into a tapered, acuminate apex; GP ventral margin invaginated, covered anteriorly by MT. Gonoplac (GL) shorter than GA, broad, and obtusely arched ventrad; from LH, GL base has a rounded dilation on the anteroventral margin. GL narrows toward the apex; from LH, GL apex slants ventrad; apical cleft (AC) reduced, resulting in a slight apical notch. From LH, GL possesses a pronounced sclerotization that traverses the length of the structure, terminating just before the AC. GL dorsal and ventral margins relatively smooth.

Discussion

As a means to consider the validity of Ilomantis , we examined the female genital complexes of the species included in Nilomantis and Ilomantis for potential intergeneric diagnostic characters. The shape of the dilation on the anteroventral margin of the gonoplac (GL) varies between the genera, with Nilomantis possessing a rounded dilation, whereas Ilomantis features a dilation that is approximately rectangular in shape (compare Figs 3 View Fig. 3 and 4 View Fig. 4 ). Furthermore, in Nilomantis the apex of gonapophysis IX (GP) is acuminate, whereas in Ilomantis the apex of GP is mammiform to approximately rounded in shape (compare Figs 5 View Fig. 5 and 6 View Fig. 6 ). These character states were able to consistently and unambiguously distinguish the genera, which, when compared against external morphological characters, male genitalic characters, and geographic distribution, enabled us to resurrect Ilomantis as a valid genus with confidence.

We likewise examined the female genital complexes of I. thalassina and I. ginsburgae sp.n. as a site for potential interspecific diagnostic characters. We found that gonapophysis VIII (GA) and GL feature compelling interspecific character states that proved successful in delimiting the species. Generally, Ilomantis thalassina features broader, more robust gonapophyses and gonoplacs than I. ginsburgae sp.n. (compare Figs 3 View Fig. 3 and 5 View Fig. 5 ). Within I. thalassina , GA features a pronounced medial outgrowth (MO); GA anterodorsal margin is moderately sclerotized, with the sclerotized region concluding just posterior to the “heel” of GA. The apical cleft (AC) of GL is distinctly divergent, the resultant lobes blunt apically; the ventral and dorsal margins of GL are rugose, sculpturate (see Fig. 3 View Fig. 3 A). However, in I. ginsburgae sp.n., MO of GA is reduced; and GA anterodorsal margin is less sclerotized than in I. thalassina , with the region of sclerotization terminating just prior to the apical lobes (AL). The AC of GL is significantly reduced, with the lobe of the dorsal margin appearing to converge with the ventral lobe, resulting in a slightly notched, acuminate apex; GL ventral and dorsal margins are smooth (see Fig. 3 View Fig. 3 B).

Although the number of specimens were limited, we examined intraspecific variation within 2 females of I. thalassina and 3 females of I. ginsburgae sp.n.; variation was most frequently observed in the apical lobe (AL) when viewed from the lateral perspective, ranging from rounded, to blunted, to angled in shape. However, this might be due to AL being a membranous structure, which can be actively or passively moved by an insect, and which might also slightly change shape when submerged within ethanol. Furthermore, AL is a lobe-like apical dilation of GA that is folded toward the external surface along the ventral margin, which could lend AL a varied appearance. We found that the overall shape of the female genitalia was more uniform in comparison to the intraspecific variation of character states observed in male genitalia, specifically in the overall length and width of the apical process (ap) of L4B, as well as the shape and sclerotization of the anterior margin of ap (see Fig. 10 View Fig. 10 ) of the one I. thalassina male and four I. ginsburgae sp.n. males examined.

An examination of the female genital complexes of Nilomantis floweri (n =1) and N. edmundsi (n =1) led to the addition of new characters with which to delimit the species. In particular, N. floweri features a gonocoxa VIII (VF) with a rounded internal margin; which, in N. edmundsi , is approximately angular (see Fig. 6 View Fig. 6 ). From LH, VF is without projection in N. floweri , whereas VF features a distinct knob-like projection that is directed dorsad (see Fig. 4 View Fig. 4 ). The apical lobe (AL) of N. floweri is heavily ciliated, while in N. edmundsi AL cilia were not observed across the majority of its surface (see Figs 4 View Fig. 4 and 6 View Fig. 6 ). Lastly, the ventral margin of the gonoplac (GL) is rugose and the dorsal margin is relatively smooth in N. floweri , whereas both the ventral and dorsal margins of GL in N. edmundsi are relatively smooth (see Fig. 4 View Fig. 4 ).

The examined specimens were collected between 116 to 13 years ago, with the majority collected around 50 years ago. With material of this age, desiccation and damage from drawer movement, museum environmental conditions (e.g., fluctuations in temperature or humidity), and specimen handling may occur. While we took great pains to ensure that the entire female and male genital complex of each specimen was removed intact, we were unable to isolate the spermatheca, vestibular floor, and the laterosternal shelf of the female genitalia. This might be due to the fact that the genitalia of these species are membranous, and when coupled with specimen age, more susceptible to being destroyed over time or while submerged in potassium hydroxide, a solution frequently used to clear insect genitalia. While we were not able to access these structures within the female genital complex of Ilomantis and Nilomantis , we were still able to find characters on the gonapophyses, gonoplacs, and gonocoxae, which unambiguously delimited the genera and the species.

Our investigation of mantodean female genitalia revealed a novel character system that successfully resurrected Ilomantis as a valid genus, delimited the species contained within both Ilomantis and Nilomantis (i.e., I. thalassina , N. floweri and N. edmundsi ), as well as described a new Malagasy praying mantis species (i.e., I. ginsburgae sp.n.). These results underscore the utility of female genitalia in Mantodea taxonomy, and subsequently demonstrate the need for thorough examination of female genital complexes as sites of taxonomic characters. Furthermore, by describing both male and female genitalic characters (when available), the ability to diagnose females in externally homogenous genera might be resolved within Mantodea . For this study, traditional taxonomic data, such as external morphology, male genitalic characters, and geographic distribution, supported the results of the investigation of the female genitalic character system. As such, it is our hope that future taxonomic descriptions of praying mantises assess female genitalic characters in addition to traditional taxonomic treatments. A more thorough investigation of female genitalia across a wide taxon sampling might provide a new motif from which to build a novel taxonomic character system.