The Naucoridae (Heteroptera: Nepomorpha) of Madagascar, with revisions of Temnocoris and Tsingala (Laccocorinae)

The island nation of Madagascar was surveyed extensively through a series of expeditions to determine the fauna of Naucoridae. Previously, 17 species in four genera had been reported from the country. All taxa previously recorded from Madagascar were re-collected, with the exception of three species, Macrocoris flavicollis Signoret, Temnocoris starmuhlneri Poisson, and Tsingala nossibeanus (Bergroth). Macrocoris flavicollis is removed from the list of species occurring in Madagascar. Within Laccocorini (Laccocorinae), a new genus, Gonioathrix n.gen. is described; Temnocoris and Tsingala are revised; three new species are described in Temnocoris (T. leachi n.sp., T. montandoni n.sp., T. poissoni n.sp.) and four in Tsingala (T. angulata n.sp., T. latiforma n.sp., T. spatulata n.sp., T. trilobata n.sp.). Lectotypes are designated for Afronaucoris madagascariensis (Montandon), Tsingala humeralis (Signoret), and T. naucoroides (Montandon). In Macrocorinae, a new species of Macrocoris, M. namorona n.sp., from Ranomafana National Park is described. These taxonomic actions bring the total for the country to five genera and 25 species. Distributions, habitat associations, and a key to the species are presented.


Introduction
Madagascar is well-known for its high biotic diversity and high endemism at both species and higher taxonomic levels, as well as the ongoing loss of taxa to environmental degradation [1,2]. It has been categorized as one of the eight most important biodiversity hotspots based on richness and endemism of vertebrates and plants and loss of natural vegetation [3]. It has also been considered a hotspot for freshwater biodiversity because of its unique fish and invertebrate communities [4,5]. Endemism levels in various freshwater groups range from 50 to 100% [6,7] but among stream insect taxa, more than 95% are endemic to Madagascar [8]. Notably, this endemism includes many species radiations from in situ speciation processes on the island [9]. For most groups, ancestors arrived from mainland Africa in the Cenozoic Era [10][11][12], with some notable more ancient exceptions [13]. While various charismatic terrestrial vertebrate lineages like lemurs, amphibians, day geckos and chameleons are among the best known

Nomenclatural acts
The electronic edition of this article conforms to the requirements of the amended International Code of Zoological Nomenclature, and hence the new names contained herein are available under that Code from the electronic edition of this article. This published work and the nomenclatural acts it contains have been registered in ZooBank, the online registration system for the ICZN. The ZooBank LSIDs (Life Science Identifiers) can be resolved and the associated information viewed through any standard web browser by appending the LSID to the prefix ""http://zoobank.org/"". The LSID for this publication is: urn:lsid:zoobank.org:pub:58B7E709-8498-487B-B292-2F81E3767F8A. The electronic edition of this work was published in a journal with an ISSN, and has been archived and is available from the following digital repositories: PubMed Central, LOCKSS.

Genus Temnocoris Montandon, 1897
Temnocoris Montandon 1897b: Verh. Zool. . Type species: Temnocoris translucidus (Montandon, 1897), by monotypy. This Madagascar endemic genus was erected by Montandon [25] to contain the species T. translucidus Montandon; all other currently recognized species and subspecies were described by Poisson in the middle of the 20th century. The genus currently contains eight species, two of which are further apportioned into subspecies, one of which is synonymized here. Temnocoris can easily be distinguished from the other two genera of Laccocorinae in Madagascar by the anterior margin of the head, which is sharply margined and with a fringe of hairs in Temnocoris (Fig 1B), bullnosed and hairless in Tsingala (Fig 1C), and bluntly angled and hairless in Gonioathrix (Fig 1A).
Temnocoris is a relatively straight-forward genus taxonomically because readily apparent characters are available separately for males and females of most species. The phallosoma and parameres are the most reliable distinguishing features in the males, with additional characters in the shape of the pseudoparameres (medial lobes of tergum VIII). The shape of the female subgenital plate is diagnostic for many of the species, although Poisson did not describe this structure for his new species. Unfortunately, females of some species were not available for us to examine; thus, not all subgenital plates are given here. Few other characters presented by Poisson are reliably consistent within species; thus, these also are not presented here. Body size and dorsal coloration are intraspecifically variable and generally not taxonomically reliable. Three new species are reported here. The subgenital plates of some species are similar and of other species are unknown. Thus, determinations of females for some species might require association with identifiable males. This genus is not commonly collected, and when it is found, usually only a few specimens are taken. It is known only from lotic systems; we have collected it mostly on sandy substrates.
Many of Poisson's descriptions referenced "subbrachypterous" specimens. This alary condition consists of forewings with non-overlapping membranes, in which each membrane extends from the wing apex forward along the lateral margin almost to the equivalent level of the tip of the hemelytral commissure (e.g., Fig 5A), claval sutures that are suppressed and only faintly visible, and hindwings barely achieve abdominal tergum II. We refer to this condition with submacropterous forewings and micropterous hindwings as submacropterous, in reference to the visible forewings. In contrast, some conspecific specimens are macropterous with overlapping membranes of the forewings, typical of adult Heteroptera, and fully developed hindwings extending approximately to abdominal tergum VII (e.g., Fig 4A). (Fig 4) Temnocoris ambositrae Poisson 1951: Mem. Inst. Sci. Madag. A5: 104-106 (original description).

Temnocoris ambositrae Poisson, 1951
Temnocoris ambositrae: La Rivers 1971, Biol. Soc. Nev. Mem. 2: 79 (catalog incl. all subspecies) . Temnocoris a. ambositrae: Poisson 1963, Bull. Inst. Fr. Afr. Noire 25: 1181. Temnocoris a. ambositrae: La Rivers 1974, Biol. Soc. Nev. Occas. Pap. 38: 13 (catalog Discussion. Two subspecies were described by Poisson: T. ambositrae betiokyi Poisson [26] and T. ambositrae magnus Poisson [27]; thus including the nominate subspecies, three subspecies are known. Temnocoris a. betiokyi was described based on only four characters of one male specimen: smaller size, pronotum 3× wider than long, scutellum twice as long as wide, and right lobe of segment VIII as shown in his Fig 27B. The T. a. magnus description was based on three characters of both sexes from Ikopa River at Marovoay-Majunga: larger than the nominate subspecies, two small sublinear markings on the pronotum and a rounded spot on the anterior margin of the pronotum that are more reddish than other markings, and the ventrolateral subapical lamellar expansion of the aedeagus is more pronounced. We do not have enough comparative material from throughout the range of the species from which to assess the validity of these subspecies designations; however, we suspect that this is simply intraspecific variation that does not warrant recognition as subspecies. Diagnosis. The aedeagus combined with the right paramere is diagnostic for males; the apex of the aedeagus is rounded on the left side and hooked on the right, and the subapical flap on the right side is reflexed dorsad (Fig 4C). Although one other species (T. montandoni n.sp.) has a similar aedeagus shape, T. ambositrae can be distinguished from it by the right paramere, which is elongate and angled near the middle (Fig 4E). The subgenital plate shape can distinguish the females, although other species have a similar shape and the conditions for females of some species are unknown. More specifically, the lateral margins are straight to slightly concave and convergent to a roundedly truncate apex (Fig 4F).

Temnocoris andringitrae Poisson, 1952
Temnocoris andringitrae: La Rivers 1971, Biol. Soc. Nev. Mem. 2: 79 (catalog). Discussion. This species was based on one male and two female "subbrachypterous" specimens. Nothing further has been published concerning this species other than its inclusion in the La Rivers catalog [22]. This species is little known and poorly understood. Poisson [29] characterized the species based on color, the vertex 1.12× wider at base of the eyes than length at midline, the pronotum with posterolateral corners slightly curved posteriorly and 2.8-3.2 times wider at the base than long at the middle, and the scutellum 2.20× wider at base than long. He gave the lengths of two specimens as 11.5 and 11.8 mm, but did not specify the sexes. Our two adult males measure 11.8 and 12.0 mm. Diagnosis. This is among the largest species of Temnocoris. The aedeagus is diagnostic with the slender apex with recurved tip (Fig 5C). The pygophore is asymmetrical with the right side extending further forward to approximately half the distance of the right paramere ( Fig  5C). The pseudoparameres have truncate posterior margins and broadly rounded posteromedial corners (Fig 5B), and the parameres are similarly shaped (Fig 5D and 5E). The female subgenital plate lateral margins are convergent to a roundedly truncate apex, and the posterolateral angles of mediosternite VI are elevated and forming pockets above laterosternite VII (Fig 5F).

Temnocoris dubius Poisson, 1951
Diagnosis. The apex of the aedeagus ( Fig 6B) is unique among known species of Temnocoris; however, Poisson's Fig 35c was reversed and the hook should be directed to the right. Poisson is known to have presented other figures in reverse (e.g., T. perplexus aedeagus). The shapes of the parameres (Fig 6C) and pseudoparameres (Poisson [26], Fig 34A) are also diagnostic. Females are not known.

Discussion
This is one of the more common species of Temnocoris, although after the original description, nothing has been published other than its inclusion in the La Rivers catalog [22].

Diagnosis
The male can be easily recognized by the aedeagus, with the short, narrow distal end that angles to the right with a truncate apex ( Fig 7C). The lateral lobes of tergum VIII are also diagnostic with the straight lateral margin that angles 30 degrees at midlength to continue straight to the posterior end ( Fig 7B). The parameres are short and similar to each other in size, but differ in the lengths of the distal margins and degree of angle of the anteriormost corners (Fig 7D and 7E). The female subgenital plate is unique among the species for which it is known; it is about as wide as long and the lateral margins angle convergently at~45 degrees to the wide, distinctly shallowly concave distal margin (Fig 7F).

PLOS ONE
The Naucoridae of Madagascar posterolateral corners bluntly acute, posterior margin nearly straight, anterior margin straight; ventrally, propleuron pale-yellow, mostly pruinose but with anterior and median lighter yellow area, anterior lighter yellow lobe extending posteriorly approximately to middle of procoxa. Scutellum surface irregular, triangular, yellow with black speckling, lateral margins distinctly sinuate, 2.02× wider than long, width 3.40, length 1.68. Hemelytra yellow with profuse black speckling throughout corium, clavus, membrane and posterior third of embolium; with sparse, fine, recumbent, pale setae. Embolium length 3.48, greatest width 1.00; lateral margin unevenly convex with degree of curvature greater near posterior end, with row of short spines and fringe of long setae. Claval suture present, but suppressed; intraclaval suture absent; claval commissure length 2.08. Membrane reduced, narrowly overlapping at midline, broadly V-shaped, extending anteriorly to claval commissure and along costal margin almost to embolium. Hindwing extending to tergum II. Metaxyphus broad, with acuminate apex. All leg segments pale yellow, protarsomere 2 and all pretarsi darker. Profemur elongate, wide, anterior margin with dorsal and ventral rows of golden hairs sandwiching one row of shorter, wide, brown setae. Distal 3/4 of protibia and two-segmented protarsus with dense ventral pad of setae. Propretarsus with short, stout, paired, movable claws. Mesofemur with anteroventral and midventral rows of elongate setae; metafemur with anteroventral row of mixed short and long setae, a mid-ventral row of short, spinose setae, and posteroventral surface set with short spinules. Mesotrochanter and mesofemur with profuse brush of light colored setae on posterior margin; Metatrochanter with brush of setae less prevalent and with distinctly rounded angle on posterior margin ( Fig 8B). Elongate, narrow, profuse pad of setae on mesotibia and mesotarsomeres 2 and 3. Long golden swimming hairs sparse on mesotibia and tarsus, profuse on metatibia and tarsus. Middle and hind legs with tarsomere 1 extending beneath tarsomere 2. Meso-and metathoracic pretarsal claws long, straight, with slight curvature apically. Leg measurements as follows: foreleg, femur 2.12, tibia 1.56 Abdomen. Dorsally, terga II-VII yellow and lined with black on posterior margins; lateral margins of III-VII with regular row of short, stout, yellow spines and tuft of elongate setae at posterolateral corners. Tergum VIII with medial lobes (pseudoparameres) black, quadrate in appearance, with mesal margins convex, posteromedial corners narrowly rounded and posterolateral corners square or nearly so, width ca. 0.67× width of lateral lobes (Fig 8C). Ventrally with mid-ventral longitudinal band of elongate setae. Sterna II-V entire, VI-VII divided into medio-and laterosternites. Posterior margins of sterna III-IV symmetrical and nearly straight. Posterior margin of sternum V with median convexity directed to right, VI-VII symmetrical. Posterolateral corners of II-IV right angled, V acute. Aedeagus elongate, stout, widest near middle, gradually tapering apically, with apex rounded and deflected to right side (Fig 8D). Pygophore with anterior margin concave and broadly V-shaped between parameres, brush of long setae most prominent posteriorly (Fig 8D). Parameres asymmetrical; left paramere with all margins convex except posteromesal corner concave, elongate setae on distal half of dorsal surface and along mesal margin and anterior corner (Fig 8E); right paramere with mesal margin straight, anterior corner narrowly rounded, posteromesal corner convex, stout setae on most of dorsal surface (Fig 8F).

Diagnosis
The angulate posterior margin of the metatrochanter in both sexes is similar to that of Temnocoris poissoni n.sp. The female subgenital plate with the distinct apical lobes also is similar to that of Temnocoris poissoni n.sp., but the lobes are flap-like and the lateral margins are convergent at a much less severe angle (Fig 8G), and the right parameres of males of the two species are dramatically different. Also in the male, the shape of the aedeagus is distinct in that it tapers in the apical half to a rounded apex which appears deflected to the right (Fig 8D).

Discussion
This species co-occurred with Tsingala humeralis in Mahajanga Province. We collected this species in slower water in two stream systems, including at the margin in pools.

Etymology
The specific epithet honors William Elford Leach who worked in the Natural History Department of the British Museum in the early 1800s and is credited as the systematic authority for the family Naucoridae.

PLOS ONE
The Naucoridae of Madagascar with anteroventral and mid-ventral rows of elongate setae; metafemur with anteroventral row of mixed short and long setae, a mid-ventral row of short, spinose setae, and posteroventral surface set with short spinules. Mesotrochanter and mesofemur with profuse brush of light colored setae on posterior margin; Metatrochanter with brush of setae less prevalent and with posterior margin shallowly convex, without angle ( Fig 9B). Elongate, narrow, profuse pad of setae on mesotibia and mesotarsomeres 2 and 3. Long golden swimming hairs sparse on mesotibia and tarsus, profuse on metatibia and tarsus. Middle and hind legs with tarsomere 1 extending beneath tarsomere 2. Meso-and metathoracic pretarsal claws long, straight, with slight curvature apically. Leg measurements as follows: foreleg, femur 2.64, tibia 1.78 Abdomen. Dorsally, terga II-VII brownish-yellow and lined with black on posterior margins; lateral margins of III-VII with regular row of short, stout, yellow spines and tuft of elongate setae at posterolateral corners. Tergum VIII with medial lobes (pseudoparameres) black, with posteromedial corners narrowly rounded and posterolateral corners obtuse, width ca. 0.80× width of lateral lobes (Fig 9C). Ventrally with mid-ventral longitudinal band of elongate setae. Sterna II-V entire, VI-VII divided into medio-and laterosternites. Posterior margins of sterna III-IV symmetrical and nearly straight. Posterior margin of sternum V with median convexity directed to right with notch to left of midline, VI-VII symmetrical. Posterolateral corners of II-IV right angled, V acute. Aedeagus elongate and stout, left side slightly convex until broadly rounded apex, right side with subapical bulge basal to pronounced concavity, acuminate hook at apex (Fig 9D). Pygophore with anterior margin deeply, broadly, and asymmetrically U-shaped between parameres, brush of long setae most prominent posteriorly (Fig 9D). Parameres asymmetrical; left paramere with lateral and mesal margins nearly straight and shallowly convergent to broadly rounded apex, elongate setae near apex (Fig 9E); right paramere with lateral margin concave at middle, mesal margin convex, apex broadly rounded, elongate setae on mesal margin and apex (Fig 9F).

Macropterous male and female
Unknown.

Diagnosis
The posterior margin of the metatrochanter is not angulate in either sex. In males, the shape of the aedeagus is distinct in that the apex is sharply hooked on the right side, which is immediately distal to a deep concavity and lateral bulge on the right (Fig 9D); the shape of the right paramere is also distinct (Fig 9F). The aedeagus and parameres are similar to those of T. dubius; however, the aedeagus is more sharply hooked and with a more pronounced subapical notch and bulge, and the paramere shapes are slightly different. The female subgenital plate lateral margins are shallowly concave and converge to a rounded apex with median notch (Fig 9G).

Discussion
This species was collected at only one locality, Ambohitantely Special Reserve on the central highland plateau. Both males are distinctly brownish-orange in color, whereas females are more yellowish.

Etymology
The specific epithet honors Arnold Lucien Montandon, the French naturalist who worked in the Grigore Antipa National Museum of Natural History in Bucharest, Romania, and described more than 400 species [31], including numerous species of Naucoridae.

Discussion
The original description was based on one macropterous female [26].
The following year, based on two male and two female subbrachypterous specimens, Poisson [29] provided a supplemental description, including of the male parameres and aedeagus; however, labelling of the left and right parameres was reversed and the aedeagus figure was reversed horizontally. Because he slide-mounted these structures on a single glass slide, it is likely that he either examined the microscope slide upside-down or mounted the structures upside-down on the slide.

Diagnosis
The aedeagus gradually becomes slender in the distal third, angles right, and ends in a tiny apical hook to the right ( Fig 10C). The parameres are similarly shaped, although the length of the left paramere is 1.1× that of the right (Fig 10D and 10E). The pseudoparameres are broadly rounded ( Fig 10B). The female subgenital plate is about as long as it is wide; the lateral margins are shallowly concave and converge to a broadly rounded apex (Fig 10F) and is similar in shape to those of T. ambositrae and T. montandoni n.sp.
Abdomen. Dorsally, terga II-VII light-brown and lined with black on posterior margins; lateral margins of III-VII with regular row of short, stout, yellow spines and tuft of elongate setae at posterolateral corners. Tergum VIII with medial lobes (pseudoparameres) black, quadrate in appearance, with mesal margins convex, posteromedial corners rounded and posterolateral corners square or nearly acute, width ca. 0.75× width of lateral lobes (Fig 11C). Ventrally with midventral longitudinal band of elongate setae. Sterna II-V entire, VI-VII divided into medio-and laterosternites. Posterior margins of sterna III-IV symmetrical and nearly straight. Posterior margin of sternum V with median convexity directed to right with abrupt concavity to left of midline, VI-VII symmetrical. Posterolateral corners of II-IV right angled, V acute. Aedeagus elongate, stout, left side nearly straight until broadly rounded apex (Fig 11D). Pygophore with anterior margin apparently symmetrical, deeply and broadly V-shaped between parameres, brush of long setae most prominent posteriorly (Fig 11D). Parameres asymmetrical; left paramere with anterior margin convex, mesal margin concave, elongate setae on distal half of dorsal surface and on ventral surface facing aedeagus (Fig 11E); right paramere with apical half acuminate, mesal margin straight, anterior margin sinuate, stout setae on margins at apex (Fig 11F).

Forewing submacropterous female
Paratypes (n = 2), length 9.12-9.16 (mean = 9.14); maximum width 5.84. Similar to submacropterous male in general structure and coloration with following exceptions: Protarsus onesegmented. Pads of setae less pronounced on pro-and mesotibiae and tarsi. Metatrochanter with posterior angle less pronounced. Sternum V divided into medio-and laterosternites. Laterosternite V with posterior margin elevated forming a pocket near mediosternite. Posterior margins of all sterna symmetrical. Subgenital plate (mediosternite VII) lateral margins at angle greater than 45˚to long axis of body in basal half (sometimes nearly horizontal), becoming concave in apical half, terminating in a pair of rigid apical lobes with a U-shaped concavity between (apical lobes tend to be reflexed dorsad), 1.43× wider than long, width 1.66, length 1.16 (measured to tip of apical lobe) (Fig 11G).

Diagnosis
The angulate posterior margin of the metatrochanter, which is more pronounced in males, is similar to that of Temnocoris leachi n.sp. The female subgenital plate with the almost horizontal lateral margins is unique, and the rigid (not flap-like) apical lobes (Fig 11G) are similar to, but distinct from, those of Temnocoris leachi n.sp. (compare with Fig 8G). In males, the shape of the aedeagus is distinct in that the apex is broadly rounded on the left side (Fig 11D) and the right paramere being non-lanceolate, but with the apex acuminate, is unique among described species of Temnocoris (Fig 11F).

Discussion
This species was collected on the sand in two unshaded, shallow, sandy streams, one with water temperature 106˚F (= 41.1˚C).

Etymology
The specific epithet honors Raymond A. Poisson for his many contributions to the taxonomy of African aquatic Heteroptera in the middle of the 20th century. Temnocoris scarletti Poisson, 1941 (Fig 12) Temnocoris scarletti

Discussion
Two forms of T. scarletti were described in the same paper [32]. Poisson based the species description on a single male macropterous specimen and the form modestus on two male and two female subbrachypterous specimens. Poisson (1941) clearly characterized modestus as the brachypterous form of T. scarletti; thus, although he described it prior to 1961 and gave a formal name, modestus is recognized only at an infrasubspecific level [33]. However, La Rivers (1971) incorrectly listed both forms as subspecies in his catalog. The type locality for T. scarletti was not given in the original description.

PLOS ONE
The Naucoridae of Madagascar

Diagnosis
The left paramere with pronounced lobe in the distal half of the mesal margin (Fig 12C and 12D) and the pseudoparameres with the produced posteromesal lobes are unique and diagnostic in the male (Fig 12B). The female subgenital plate is deeply cleft with the cleft narrowly rounded at the anterior end and extending approximately half the length of the plate (Fig 12F).

Discussion
This species is known from only a single male specimen. The description involved mostly color pattern, but Poisson [30] also gave measurements of the front leg and characteristics and figures of the parameres and aedeagus. He indicated that this species appears similar to T. dubius, but that it differs in the nearly symmetrical parameres and truncate aedeagus. He reported its length to be 14 mm and that this is the largest species of the genus [30]. Although we have not seen the type specimen, the slide-mounted aedeagus and parameres are housed in the Poisson slide collection in the USNM and photos of these structures are presented here (Fig 13A-13C). The parameres were not labeled on the slide; thus, left and right are interpreted here based on the figures and text in the original description [30].

Diagnosis
The parameres are very similar in size and shape (Fig 13B and 13C), and the aedeagus is narrowed distally with a truncate apex and short hook (Fig 13A).

Discussion
This is the type species of the genus and was described based on one specimen, which Montandon indicated was deposited in the MNHN; however, the specimen was not found there two recent visits. Following the original description by Montandon [25], Poisson [32] provided a supplemental description based on three subbrachypterous males, as well as distributional information and comparative notes [26,27,34]. As such, our concept of T. translucidus is based

PLOS ONE
The Naucoridae of Madagascar

PLOS ONE
The Naucoridae of Madagascar on the Poisson [32] supplemental description and genitalia slides in the USNM, which agree well with our specimens presented here.

Diagnosis
This is a relatively small species and comparatively lighter in pigmentation than congeners. Our specimens measured 7.68-10.56 (mean = 8.61) and Poisson [32] gave the size range as  reported the color to be the same as that of T. dubius and T. scarletti.
The eyes are noticeably more narrowed anteriorly (Fig 14A) than in congeners [26]. The male genitalia and pseudoparameres are diagnostic; the shape of the aedeagus (Fig 14C) is readily recognizable and the parameres are dramatically asymmetrical, with the left paramere short and subtriangular (Fig 14D, whereas the right paramere is slender, elongate, and gently curved (Fig 14E). The pseudoparameres are darkly colored and the posterolateral corners produced laterally to form a hooklike shape (Fig 14B). The female subgenital plate lateral margins are shallowly concave and converge to a shallowly to deeply concave apex (Fig 14F).

Material examined
All specimens macropterous unless otherwise noted. Tsingala was recently erected to contain the Madagascar species formerly held in Heleocoris Stål, 1876, which was shown to be polyphyletic with three distinct, independent clades [21]. Because the type species of Heleocoris is H. obliquatus Spinola, which is in a clade with Indian species, T. humeralis was designated as the type species of Tsingala [21]. Tsingala can be distinguished from Temnocoris by the anterior margin of the head, which is bullnosed and hairless in Tsingala (Fig 1C), angulate and hairless in Gonioathrix, and sharply margined and with a fringe of hairs in Temnocoris. Tsingala is an exceptionally challenging genus with which to work at the species level. Features given by Montandon [25] and Poisson [26,35] are problematic and include the inner margins of the eyes, which was given as barely vs. noticeably convergent, but was not quantified. Pronotum proportions using the anterior and posterior widths were each compared to the middorsal length, but the reported proportions are not close to our critical measurements of the available syntypes. Paramere shapes provided in line drawings by Poisson depict intraspecific variation, although differences among species are evident. Dorsal coloration is exceptionally variable within species and is generally not taxonomically reliable. Four new species are reported here and were validated as distinct species by both the recent molecular phylogeny of the family [21] and by morphological attributes, some of which were unreported by previous authorities, including shape of the female subgenital plate (abdominal sternum VII), which we have found to be diagnostic for three of the four new species described here. Thus, features we consider taxonomically informative include parameres, female mediosternite VI, female subgenital plate, overall size, and ventral coloration. Some species are characterized by features unique to males, females, or both. Further, because certain species require either males, females, or both for identification, collectors should endeavor to collect series of specimens to ensure that both sexes are represented; however, it is common for more than one species to be present at a site, which can further confound identification.

Macropterous female
Holotype, length 9.60; maximum width across embolia 5.84. Paratypes (n = 10), length 9.20-10.00 (mean = 9.46); maximum width 5.28-5.92 (mean = 5.70). Overall shape elongate-oval. Dorsally, overall coloration dark-brown with yellowish head, pronotum, proximal 2/3 of embolium ( Fig 15A); brown, coarse punctation on head and pronotum; hemelytra irregularly brown, yellow, and finely punctate. Ventrally, abdomen light-brown, thorax yellow and medium-brown, legs yellowish. Head. length 1.28, maximum width 3.76; inner margin of eyes slightly convergent anteriorly. Synthlipsis at anterior margin 1.72, interocular distance at posteromesal corner 1.96; cuticle laterad of eye expanded. Vertex with heavy, brown punctation forming broad triangle interrupted by yellow posteromedian gap; punctation extending anteriorly as irregular, double median row of coarse punctation, flanked by dark, paramedian row of coalescent punctation; irregular row of setae marked by broken line of brown pigmentation bordering inner margin of eyes; dark-brown line of pigmentation extending from near posteromedian corner of eye to posteromedian margin of head. Labrum with basal sulcus, transverse, distal margin evenly rounded, 2.07× wider than long. Antennae four-segmented, length 0.68, proportions 3, 12, 13, 8. Thorax. Pronotum yellow, scabrous, broad, 2.48× wider than long, length at midline 2.00; maximum width at posterolateral corners 4.96; transverse band across posterior 1/4 devoid of coarse punctures; large, brown punctures tending to coalesce near midline, becoming smaller and more sparse laterally, with distinct yellow impunctate subrectangular area on midline anterior to transverse band; lateral margin evenly convex, posterolateral corners rounded, posterior margin shallowly convex, anterior margin straight; ventrally, propleuron generally medium-brown except yellow lateral glabrous area. Scutellum finely punctate, triangular, black with yellow apically and along lateral margins near anterior corners, with distinctly sinuate lateral margins, 2.13× wider than long, width 3.32, length 1.56. Hemelytra finely punctate throughout; with sparse, short, golden setae on corium extending throughout membrane; cuticle irregularly minimized creating dark-brown and yellow color differences and the appearance of small tubercles. Claval commissure length (to locking mechanism) 1. 20. Embolium length 3.40 (chord measurement), greatest width 0.84; lateral margin evenly rounded; yellowish with scattered brown punctures in anterior 2/3, brown in posterior third. Hindwing extending to near middle of tergum V. Metaxyphus broad, with sharp mid-ventral ridge and papillose apex. Coxae brownish-yellow, all other leg segments yellow. Profemur elongate, inflated, anterior margin with dorsal and ventral rows of golden hairs sandwiching one row of short, dark spines. Distal 2/3 of protibia and single-segmented protarsus with dense ventral pad of setae. Propretarsus with short, stout, paired, movable claws. Meso-and metafemora with anteroventral and mid-or posteroventral rows of spinose setae; anteroventral seta rows arcuate from ventral surface to anterior margin, ending in distal fourth; setae number 23-25 on mesofemur and 30-33 on metafemur; mesofemur midventral row with 54-57 setae, with the distalmost 14-15 setae spaced distinctly more tightly; metafemur posteroventral row with 44-46 stout setae. Mesotrochanter and mesofemur with profuse brush of light colored setae on posteroventral margin; brush of setae narrowly set on metatrochanter and metafemur. Elongate, narrow pad of setae on mesotibia and mesotarsomeres 2 and 3. Long golden swimming hairs sparse on mesotibia and tarsus, profuse on metatibia and tarsus. Middle and hind legs with tarsomere 1 extending beneath tarsomere 2. Pretarsal claws long and with slight, even curvature. Leg measurements as follows: foreleg, femur 2.30, tibia 1.44 Abdomen. Dorsally with lateral margins of II-VIII with regular row of short, stout, goldenbrown spines. Terga with lateral margins of II-VII each yellow anteriorly, dark brown at posterolateral corner. Ventrally with dense mid-ventral band of elongate setae beginning on III, continuing and becoming more profuse to and including subgenital plate. Posterior margins of mediosternites III-VI symmetrical and nearly straight. Posterior margin of laterosternite V produced at middle with narrowly rounded apex, distal half concave. Posterolateral corners of mediosternite VI produced posteriorly as blunt tabs. Subgenital plate (mediosternite VII) lateral margins slightly convergent with angle of incidence of~10% in basal 2/3, then increasing to~60% in distal 1/3, to short, shallowly concave, truncate apex; 1.15× wider than long, width 1.38, length 1.20 (Fig 15F).

Macropterous male
Paratypes (n = 10), length 7.84-9.60 (mean = 9.36); maximum width 4.80-5.60 (mean = 5.55). Similar to female in general structure and coloration with following exceptions: Protarsus twosegmented. Pads of setae more pronounced on pro-and mesotibiae and tarsi. Posterior margins of mediosternite III-IV straight, V symmetrical and deeply concave, VI asymmetrical, shallowly concave, and more expansive on left side, VII symmetrical and straight. Aedeagus elongate, stout, parallel sided and widest in basal half, left lateral margin in distal half straight and angled toward apex, right lateral margin gently convex in distal half until apex, apex https://doi.org/ 10.1371/journal.pone.0272965.g015 slightly deflected to right (Fig 15C). Pygophore with anterior margin concave between parameres, slight asymmetry in anterior production of lateral lobes, sometimes with incipient intermediate lobe, brush of long setae most prominent posteriorly (Fig 15C). Parameres asymmetrical; left paramere with margins generally straight, posteromesal corner obtusely angled, anterior corner acutely angled, both corners broadly rounded, elongate setae extending mesad from almost entire mesal margin and anterior corner ( Fig 15D); right paramere with lateral margin subtly angled creating broadly concave appearance, posterior and mesal margins straight, posteromesal corner narrowly rounded and right angled, anterior corner produced to a blunt point, elongate setae extending mesad from almost entire mesal margin and anterior corner (Fig 15E).

Diagnosis
This species is characterized by the shape of the female subgenital plate, in which the lateral margins are markedly angled at 2/3 length to become noticeably more convergent, and terminating in a short, truncate apex with a shallow concavity (Fig 15F). The hemelytra are punctulate and with the integument variably expressed with the surface continuously normally sclerotized or the sclerotization minimized creating lighter areas; thereby giving many specimens a speckled appearance (Fig 15A). Also, sparse, short, golden hairs of the hemelytra extend throughout the membrane. The abdominal sterna usually are orangish-brown.

Discussion
Although the speckled appearance of the hemelytra can be seen on T. angulata n.sp., other species can also have this appearance. Because the parameres are not sufficiently uniquely shaped to be diagnostic, males should be associated with identifiable females. We collected this species in a variety of lotic situations, including among vegetation at the margins of small streams, rock pools of a waterfall, and a silty, vegetated slow area of a large river. In the recent phylogeny of the family [21], this species was given as Tsingala sp. C and was sister to Tsingala trilobata n.sp.

Etymology
The specific epithet angulata (= angular, cornered), a Latin adjective, is in reference to the angled posterolateral margins of the female subgenital plate.

Lectotype designation
We examined two syntype males on loan from MCSN and Montandon-determined specimens from MNHN and USNM. One of the MCSN syntypes had historical dermestid damage; thus, we dissected the genitalia from this ( Fig 16B) and the male USNM specimen. The parameres and other features are consistent between these dissected males; thus, we are confident that the Montandon-determined females at USNM (Fig 16C) can be associated as conspecific with the male syntypes. The undissected syntype male at MCSN is here designated as the lectotype (Fig 16A) in order to fix the identity of the species. The dissected male with dermestid damage at MCSN is a paralectotype.

Diagnosis
This is the smallest species of Tsingala; body length was given as 8 mm [20] and 8-9 mm [35], but our specimens measure 7.28-9.04 mm. The female subgenital plate is broadly rounded, can have a slight median notch (Fig 16C), and is not as dorsoventrally robust as in most congeners. The posterolateral corners of female mediosternite VI are broadly rounded and the  posterior margin of laterosternite V is roundly sinuate without sharp angles (Fig 16C). The ventral color is light-brown to orangish-brown. The dorsal color is variable, but generally mottled medium-to dark-brown. The parameres of T. humeralis have been illustrated and shown to be variable among individuals [20 (Fig 22)]; shown here are parameres and other structures dissected from a Montandon-determined male housed at USNM (Fig 16D-16F). Male mediosternite V posterior margin is evenly concave to the laterosternite corners.

Discussion
Although early reports gave the distribution only as Madagascar [20,35,36], this species has since been determined to be widespread [37] and has been recorded from throughout Madagascar, including from Nossi-Be Island, the type locality [28]. It was reported to also occur on three of the Comoro Islands [37], although we have not seen these specimens and cannot verify the records. This species occurs in the margins of streams, including among vegetation, and has been recorded in puddles and marshes [28]. We have also collected it in residual pools of dry stream beds. Although most specimens are hindwing macropterous, brachypterous individuals occur and have forewing membrane minimized and the claval commissure is longer than the scutellum. Antananarivo [34]; Antsiranana, Fianarantsoa, Mahajanga, Toamasina, Toliara [28].

PLOS ONE
The Naucoridae of Madagascar swimming hairs sparse on mesotibia and tarsus, profuse on metatibia and tarsus. Middle and hind legs with tarsomere 1 extending beneath tarsomere 2. Pretarsal claws long and with slight, even curvature. Leg measurements as follows: foreleg, femur 2.44, tibia 1.54, tarsomeres 1-2 0.24, 0.28; middle leg, femur 2.38, tibia 1.80, tarsomeres 1-3 0.20, 0.46, 0.52; hind leg, femur 2.82, tibia 2.80, tarsomeres 1-3 0.22, 0.96, 0.80. Abdomen. Dorsally with lateral margins of II-VIII with regular row of short, stout, goldenbrown spines. Terga with lateral margins of II-VII each yellow anteriorly, dark brown at posterolateral corner. Ventrally dark-brown with dense mid-ventral band of elongate setae beginning on III, continuing to posterior margin of abdomen. Posterior margins of mediosternite III and IV straight, V with slight asymmetry and deeply concave, VI asymmetrical, shallowly convex, more expansive on left side, VII symmetrical and shallowly convex. Aedeagus elongate, stout, widest at middle of part visible beyond pygophore, left lateral margin in distal half straight and angled toward apex, right lateral margin gently convex throughout most of length until apex, apex slightly deflected to right (Fig 17C). Pygophore with anterior margin concave between parameres, slight asymmetry in anterior production of lateral lobes, brush of long setae most prominent posteriorly (Fig 17C). Parameres dramatically asymmetrical; left paramere broad, with left margin straight for most of length, posterior margin shallowly convex, mesal margin straight, both corners broadly rounded, elongate setae extending mesad from distal half of near mesal margin (Fig 17E); right paramere with lateral margin sharply angled, posterior margin straight, mesal margin shallowly convex, posteromesal corner broadly rounded, anterior corner produced to a blunt point, elongate setae extending mesad from distal 2/3 of mesal margin (Fig 17F).

Diagnosis
This species can be characterized only by its unique combination of broadly expansive male parameres, especially the left paramere, and broadly rounded female subgenital plate with the posterolateral corners of mediosternite VI broadly rounded.

Discussion
This species is known only from standing water bodies in three localities in Fianarantsoa Province; two are ponds and one was from pools in a drawn-down stream. Other undescribed species also have broad parameres, but mediosternite VI posterolateral corners have small productions and in some the subgenital plates have convergent lateral margins with a truncated apex. Further, these other populations are of dramatically different body sizes; thus, this group requires further study.

Lectotype designation
In the original description, Montandon [38] indicated specimens were deposited in Genoa (MCSN), Vienna, and his personal collection. Currently, a single female syntype is housed at MCSN, three are in Vienna (one male and two females), and two in NHMUK (one male and one female). We examined the syntype female on loan from MCSN and a pair Montandondetermined specimens from MNHN. The syntypes deposited at NHMUK and NHMW were not examined. In order to fix the identity of this species, we herein designate the female deposited at MCSN as the lectotype (Fig 18A and 18B). The specimens at NHMUK and NHMW are paralectotypes.

Diagnosis
The large size and dark coloration of this species provide the first indication of its identity. This species is among the largest in the genus; it was reported as 9.5-9.8 mm in length in the original description [38]. Our specimens measure 9.12-9.92 in length. The female subgenital plate is broad and its lateral margins are convergent and nearly straight from laterosternite VI to a truncate or shallowly concave apex. The posterolateral corners of mediosternite VI are variable, ranging from broadly to narrowly rounded or with an incipient production. The posterior margin of laterosternite V in females is roundly sinuate and usually without sharp angles, although an incipient angle occasionally occurs at the inflection point. The ventral color of the abdomen is dark-brown to black. The dorsal color can be slightly lighter, with the hemelytra generally concolorous brown to dark-brown.

Discussion
This species is found throughout the country. We have collected it in a variety of aquatic habitats, including stream margins, ponds with lily pads, rock pools, and even pools on a road. The subspecies H. n. ambiguus was differentiated from the nominate form by a smaller and more slender size and shape, and by parameres with substantial differences [37]. When considering all species of Tsingala from across Madagascar, this taxon would seem to warrant species-level recognition. However, in the absence of a type or authoritatively identified specimen, the two-sentence description and illustration of only parameres renders this subspecies as a nomen dubium. Line drawings of abdominal terga 6-8, the aedeagus, and parameres of T. naucoroides were presented by ], and parameres from two populations showing intraspecific variation by Poisson [37,Fig 3)]. https://doi.org/ 10.1371/journal.pone.0272965.g018

PLOS ONE
The Naucoridae of Madagascar

Diagnosis
The inner margins of the compound eyes are subparallel in the posterior half and noticeably convergent in the anterior half [37]. Body length is � 8.5 mm. The parameres are dramatically asymmetrical and with shapes as in Fig 6 of Poisson [37].

Discussion
This species is known only from Antsiranana Province. The type locality is the island of Nossi-Bé and the species has also been reported from Sambirano River [37]. The type specimen was reported by Bergroth [39] to be deposited in the museum at Frankfurt am Main. Montandon [25] reported that he was not familiar with the species; thus, he had not seen the type, and Poisson [37] later reported the type to be missing. In the absence of a type specimen or any authoritatively identified museum specimens, we rely on the original description [39], which gave color characteristics, although generally these are not reliable species descriptors in Tsingala, and that the eyes are convergent anteriorly. Secondarily, we rely on the species concepts of Montandon [25] and Poisson [37], who redescribed the species and provided line drawings of male parameres from two populations showing intraspecific variation [37 (Fig 6)]. It is unknown upon what material Poisson based his redescription, although he gave the locality as Nosi-Be. Poisson repeated the size range given in the original description [39] as 7.8-8.5 mm and that that eyes are noticeably convergent. We have morphospecies with parameres resembling those illustrated by [37], and with female subgenital plates of various shapes; however, all of our specimens have compound eyes that are parallel or barely, rather than noticeably, convergent and some are substantially longer than 8.5 mm; thus, they apparently are not conspecific with T. nossibeanus. As such, we consider these morphospecies to represent new species and described one as T. latiforma n.sp.

Material examined
None.

Macropterous male
Paratypes (n = 5), length 8.24-9.52 (mean = 8.90); maximum width 4.88-5.80 (mean = 5.42). Similar to female in general structure and coloration with following exceptions: Protarsus two-segmented. Pads of setae more pronounced on pro-and mesotibiae and tarsi. Posterior margins of mediosternite symmetrical, III to IV straight, V deeply concave, VI distinctly concave, VII straight. Tergum VIII with pseudoparameres asymmetrical with posterior margin of left lobe mostly straight to rounded posteromesal corner, right lobe broadly rounded from mesal to lateral margins (Fig 20C). Aedeagus elongate, stout, parallel sided and widest in basal 2/3, left lateral margin in distal third straight and angled toward apex, right lateral margin mostly straight to apex (Fig 20D). Pygophore with anterior margin concave between parameres, slight asymmetry in anterior production of lateral lobes, usually with incipient intermediate lobe, brush of long setae most prominent posteriorly (Fig 20D). Parameres asymmetrical; left paramere with lateral and mesal margins generally straight, both corners broadly rounded (Fig 20E); right paramere narrow, with lateral margin broadly angled creating broadly concave appearance, posterior margin straight, mesal margin with slight concavity, both corners broadly rounded, posteromesal corner slightly deflexed (Fig 20F); elongate setae extending mesad from distal 2/3 of mesal margin and anterior corner of both parameres (Fig 20E and 20F).

Diagnosis
This species is characterized by the trilobed posterior margin of the female subgenital plate (Fig 20B) and the narrow, somewhat boomerang-shaped right paramere of the male (Fig 20F).

Discussion
We collected this species from only standing water situations, including pooled water on rocks, vegetated ponds, and mossy rocks near a waterfall. It was collected with Tsingala humeralis at Ranomafana National Park. In the recent phylogeny of the family [21], this species was given as Tsingala sp. D and was sister to Tsingala angulata n.sp.

Etymology
The specific epithet tri-(= three) and lobata (= lobed) from Latin adjectives are in reference to uniquely three-lobed posterior margin of the female subgenital plate.

Additional material examined
Antananarivo, Analamanga, Andranofena River by the bridge of RN4, next to Andranofena Sud village, 18.0844S, 47.1776E, 143018.0844S, 47.1776E, m, 21-XI-2014 [20]. The entire genus currently contains nine species, six of which are restricted to mainland Africa and the other three are in a sister clade and restricted to Madagascar. All species of Macrocoris are moderately sized to very large for the family and dorsoventrally robust. Reports of M. flavicollis occurring in Madagascar (e.g.,[40]) are not supported by our extensive collecting, nor by museum holdings that we have examined; thus, this species is removed from the list of species of Naucoridae occurring in Madagascar. Until the recent phylogeny of the family [21], Macrocoris was contained within the subfamily Naucorinae; however, this subfamily was shown to be polyphyletic and the new subfamily Macrocorinae was established for Macrocoris and its sister mainland African genus Neomacrocoris. Of the five genera of Naucoridae occurring in Madagascar, Macrocoris and Afronaucoris differ from the laccocorine genera Gonioathrix, Temnocoris, and Tsingala in having the labrum originating at the front of the head, rather than being set back posteroventrally.

Discussion
Nothing has been published on this species after its original description other than a few records of occurrence [26,28], brief notes on morphology [26,34], and inclusion in a catalog of the Naucoridae [22]. This species tends to occur among vegetation in muddy margins of slow streams. A record of this species from Cameroon [41] was later discounted as erroneous and blamed on the similarity of this species to M. flavicollis chariensis Poisson [26]. The apically widened phallosoma (Fig 22B) is atypical for the species of Macrocoris from both Madagascar and mainland Africa that we have examined. The other congeners from Madagascar have slender, arcuate phallosomas similar to that of mainland M. flavicollis.
Legs. All segments mostly brownish-yellow except brown protarsus and apices of meso-and metatarsus. Profemur with scattered brown spots on ventral and dorsal surfaces; anterior margin with dense pad of elongate, golden-brown setae, but without intervening spines; posterior margin with narrow band of spines in basal half. Protibia and tarsus with flattened inner surface, tarsus one-segmented, single claw minute. Middle and hind coxae densely covered with short, pale, recumbent setae. Metasternellum (= metaxyphus) with pronounced transverse and longitudinal carinae, thus resembling head of Phillips screwdriver directed posteroventrad. Meso-and metafemora each with posteroventral row of brown, peglike spines; spines more elongate distally on mesofemur; meso-and metafemora and trochanters with posterodorsal row of pale, elongate setae. Meso-and metatibiae with longitudinal rows of stout, reddishbrown spines and two transverse rows of long, stout spines at apices; meso-and metatibiae and tarsi with long, golden brown swimming hairs. Meso-and metapretarsal claws paired, slender, evenly curved, with basal tooth. Leg measurements as follows: foreleg, femur 4.16, tibia 3.36, tarsus 0.68; middle leg, femur 3.76, tibia 3.20, tarsomeres 1-3 0.26, 0.54, 0.84; hind leg, femur 4.52, tibia 5.28, tarsomeres 1-3 0.38, 1.02, 1.04. Abdomen. Margins of terga III-VIII exposed laterally beyond hemelytra; III-V each yellow anteriorly, brown posteriorly, VI-VIII mostly brownish-yellow; lateral margins smooth, with dense fringe of pale setae; posterolateral angles of II-V squared, VI-VII acute but not sharp, VIII rounded. Tergum V extended posteriorly, posterior margin broadly lobed on each side of midline. Tergum VIII right medial lobe strongly curved and heavily setose on posterior margin (Fig 22C). Proctiger covered with pale brown setae, acuminate apically. Ventrally brown and covered with dense, fine pile of short, recumbent setae, except narrow marginal glabrous band; mediosternites also with elongate, erect, brown setae. Sternum V posterior margin asymmetrically concave and mediosternite VI displaced asymmetrically to left. Genital operculum evenly rounded. Pygophore brown, elongate setae generally scattered and with a dense brush posteriorly ( Fig 22D). Phallosoma slender, straight in basal half, then angled left in distal half before deflexing with articulated vesica and endosoma (Fig 22D). Parameres large, 3-dimensionally robust, elongate and flanking phallosoma to end of pygophore (Fig 22D). Left paramere in ventral view with mesal margin deeply concave at middle and broadly rounded distally (Fig 22F); right paramere gently curved and cupped medially at apex (Fig 22E).

Discussion
This large species was collected only in the Namorona River and its tributaries in Ranomafana National Park. Specifically, it occurred in grassy, vegetated margins where the current was moderate to strong.

Diagnosis
This species is nearly indistinguishable from the congeners M. rhantoides and M. sikorae and was recovered as sister to M. rhantoides in the recent molecular phylogeny [21]. We have found only the left paramere to be a reliable diagnostic attribute by which to distinguish among these species. More specifically, the mesal margin in ventral view has a deep concavity at the middle and is broadly rounded distally in M. namorona n.sp., whereas the mesal margin is mostly straight beyond the base in M. rhantoides and M. sikorae. In addition, M. rhantoides is somewhat smaller than the other two. The fourth species of Macrocoris in Madagascar, M. distinctus, is easily distinguished because it is much smaller and rounder than this group of three closely related species.

Etymology
The species is named for the river within which the type series was collected.
Type material examined wings. Montandon [42] established the genus Pseudambrysus based on a superficial resemblance to the American genus Ambrysus, but with little comparative material in collections at the time. After more specimens were available to him for examination, he recognized clear distinctions between these two genera and between Pseudambrysus and Macrocoris [43]. Further, he also realized his Pseudambrysus fairmairei was already described as Macrocoris sikorae; thus, he synonymized the species but transferred it to Pseudambrysus [43]. In that work, he also transferred Macrocoris rhantoides to Pseudambrysus. Poisson continued to recognize Pseudambrysus (and Pseudoambrysus [sic]) as a valid genus [26,28], which continued until La Rivers published a catalog of the species in which the two species were transferred back to Macrocoris [22].

Discussion
In 1893, Bergroth described the three species of Macrocoris known from Madagascar at the time [39]. Four years later, Montandon must have been unaware of Bergroth's species when he erected a new genus, Pseudambrysus, to contain P. fairmairei [42], which he would later synonymize at the species level with M. sikorae, but retain in Pseudambrysus as P. sikorae [43]. Live specimens tend to be moderately green to brown anteriorly with grey to brown wings.

Diagnosis
This is among the largest of the Madagascar saucer bugs; mean length and width (mm) of our specimens are 13.12 × 7.61 (10 males) and 14.13 × 8.22 (10 females). Its general appearance is nearly identical to that of M. namorona n.sp. and M. rhantoides, although significantly larger than the latter. The most distinctive difference separating it from these two congeners is the shape of the male left paramere (Figs 22G and 24D).

Material examined
dimpled and along with additional fine irregularities, the surface has an overall matte appearance (Fig 25A); male genitalic differences between them are negligible (Fig 25B-25D).

Published records
No published records are available.

Discussion
This is the smallest species of saucer bug in Madagascar. Measurements of 16 randomly chosen specimens are length 5.84-6.80 (mean = 6.29); maximum width 3.52-4.16 (mean = 3.71). It is a common inhabitant of aquatic vegetation in ponds, marshes, swamps, rice paddies, and stream margins. This species is abundant and occurs syntopically with A. madagascariensis, but in much greater numbers.

Diagnosis
With the apparent absence of Signoret type specimens, our concept of A. parvulus is dependent on Montandon-examined specimens housed in MCSN and MNHN (see Uknown Province in Material examined). Although there is overlap in size among individuals of both species, A. parvulus is somewhat smaller than A. madagascariensis; however, surface texture of the pronotum will unmistakably distinguish between them. The pronotum of A. parvulus is smooth and glossy with only negligible indications of dimpled punctation (Fig 26A), whereas that of A. madagascariensis is obviously dimpled and less reflective because of its matte appearance ( Fig 25A). Genitalia (Fig 26B-26D) are similar to those of A. madagascariensis.