Ramulus yasini, Hennemann & Tirant, 2023

Ramulus yasini View in CoL n. sp.

( Fig. 10-11, 16 A-B)

ZooBank: http://zoobank.org/ 5D3F32DA-3D41-42EA-8206-B8F162E82FA6

Holotype, ♂, Indonesia, Morotai Island, North Maluku Regency, Daeo Majiko village , XI.-XII.2012 [ IMQC].

Paratypes

- 10 ♂, Indonesia, Morotai Island, North Maluku Regency, Daeo Majiko village , XI.-XII.2011 [ IMQC] .

- 7 ♀, 8 ♂, 3 eggs (ex ovipositor), Indonesia, Morotai Island, North Maluku Regency, Daeo Majiko village , XI.-XII.2012 [FH, No’s 1087–1 to 15, E] .

Etymology. – Dedicated to Alim Yasin (Morotai, Indonesia) who first found this species and provided specimens for study and description.

Differential diagnosis. – Very close to R. redemptus (Brunner v. Wattenwyl, 1907), that was described based on a ♂ from “ Moluccas ” and an immature ♂ from the island of Obi. Males of this new species may be separated from those of redemptus by the larger size (body length of redemptus 95.0 mm) and somewhatmore stocky shape, relatively shorter, more globose and posteriorly less constricted head ( Fig. 10 J-K) and significantly different shape of the hemi-terga of the anal segment, which are more slender, more tapered and rounded apically ( Fig 10G; rather broadened and obtusely angular in redemptus ). The very small poculum, that has the posterior margin protruded into a triangular tooth-like appendix ( Fig. 10G, I), and ventro-apically unarmed meso- and metafemora are shared with the ♂ of redemptus . Among the known Wallacean members of the genus, ♀ most strongly resemble those of R. pelengense Hennemann et al., 2021 from the island of Peleng and R. togianense Hennemann, 2021 from the Togian Islands east of Sulawesi. While the distinct armature of the mid legs is shared with pelengense and the strongly keeled and bulgy subgenital plate and prominent cephalad horns are shared with togianense . ♀ of this species can be separated by the on average larger size and distinct praeopercular organ that is formed by a an obtusely rounded, verrucose median swelling just before the posterior margin of abdominal sternum VII ( Fig. 10F). From redemptus these ♀ can readily be distinguished by the large pair of lobes of the head ( Fig. 10 L-M) and subgenital plate that is more strongly keeled and much bulgier in the posterior half with the apex obtusely angular in lateral aspect ( Fig. 10D). From ♀ of togianense this species can also be separated by the rounded, shovel-like shape of the cephalad lobes (acutely pointed and rather slender upright thors in togianense ) and distinctly armed mid and hind legs. The eggs ( Fig. 16 A-B) show morphological affinity to those of the Sulawesian R. torajanus Hennemann, 2021 but are larger with a larger micropylar plate and a notably lower outer margin of the operculum, which is inserted into the capsule almost at a right angle.

Description.

The description of the ♀ colouration is described only from dried specimens and a few pictures of live specimens taken by A. Yasin (Morotai).

♀ ( Fig. 10 A-B, D-F, L-P, 11B). Fairly large for the genus (body length including subgenital plate 147.0-166.0 mm), form slender, body surface entirely smooth, the head strongly globose and prominently armed and the subgenital plate bulgy and somewhat projecting beyond apex of abdomen ( Fig. 10D, F). Meso- and metafemora and corresponding tibiae with variably shaped triangular lobe-like teeth. General colour various shades of dull ochre and drab to greyish mid brown, sometimes olive or with a greenish hue. Occasionally there may be specimens that are all over speckled with darker tones of brown. Eyes dark reddish brown. Antennae with scapus and pedicellus coloured like the body, then gradually becoming darker towards the apex. Teeth and lobes of mid and hind legs irregularly mottled with dark brown.

Head ( Fig. 10 L-M). – Strongly globose, sub-spherical, just indistinctly longer than wide, broadest at eyes and notably narrowing towards the posterior; vertex rounded and armed with a pair of large rounded and shovel-shaped lobes, that are rather constricted and transverse at the base and gradually widen towards the tip with the anterior margin forward directed; these projecting by roughly half of the height of the head capsule ( Fig. 10L). Frons with two pits that are connected by a slightly trapezoidal impression. Eyes almost circular in outline, moderately projecting and diameter of eye about 0.4x the length of gena Antennae about 1.2x longer than head and pronotum combined, consisting of 26 antennomeres ( Fig. 10 L-M). Scapus strongly flattened dorsoventrally with both lateral margins A. PT right mesofemur in posterolateral aspect [FH]. B. PT right mesofemur in posterolateral aspect [FH]. C. PT right mid leg in lateral aspect [FH]. D. PT terminalia in lateral aspect [FH]. E. PT terminalia in dorsal aspect [FH]. E. PT terminalia in ventral aspect [FH]. G. PTfrom Daeo Majiko, head, pro- and mesothorax in dorsal view [FH]. H. PT from Daeo Majiko, head, pro- and mesothorax in dorsal view [FH]. J. PT (captive reared), head with antennae and prothorax in dorsal view [FH]. K. PT (captive reared), head with antennae and prothorax in ventral view [FH]. L. PT (captive reared), head with antennae and prothorax in lateral view [FH].

strongly deflexed and rounded, basically ovoid in dorsal aspect and roughly 2x longer than wide. Pedicellus small, oval in cross-section and only about one-fifth the length of scapus. III almost 2x longer than pedicellus, IX much shorter than all preceding and the following antennomeres gradually increasing in length. Terminal antennomere almost as long as scapus.

Thorax. – Pronotum shorter and significantly narrower than head, the sub-anterior portion narrower than the widened posterior half and with an distinctly impressed medio-longitudinal line over the entire length ( Fig. 10M). Transverse median sulcus distinct, gently curved, expanding over somewhat more than half the width of the segment and terminating in a Cshaped pit at each end. Outer portions of pronotum weakly rugulose. Meso- and metanotum with a fine and indistinct longitudinal median line and an indistinct obtuse longitudinal ridge close to the lateral margins. Mesothorax about 2.8x longer than the head and pronotum combined and about 1.3x longer than metanotum. Metanotum about 7x longer than wide.

Abdomen. – Median segment scarcely longer than wide, slightly trapezoidalwith anterior marginnarrower thanposterior marginand0.15x the length of metanotum. Abdomen excluding median segment considerably longer than head and complete thorax combined. All abdominal segments roughly uniform in width but sub-equal in length; II about 2.7x longer than median segment and 3.2x longer than wide; II-IV increasing in length, V longest segment and about 4x longer than wide, VI-VII decreasing in length with VII scarcely longer than II. Preopercular organ represented by a prominent, obtusely rounded verrucose median swelling just before the posterior margin of abdominal sternum VII that is marked by a distinctive black triangular marking ( Fig. 10F). Terga VIII-X uniform in width and somewhat narrower than preceding. VIII almost two-thirds the length of VII, IX slightly more than half the length of VIII. Anal segment notably longer than IX, with a fine medio-longitudinal keel and posterior margin distinctly bilobed with a deep median excavation that is wider at the base; the lateral angles semi-circular ( Fig. 10E). Cerci small, tapered towards the tip and gently in-curving. Subgenital plate strongly bulgy and deeply keeled longitudinally, the posterior half higher than anterior half and the apex obtusely angular in lateral aspect with the medio-longitudinal keel meeting the anterior margin almost at a right angle; slightly projecting beyond the tip of the abdomen ( Fig. 10D, F).

Legs. – All long and slender with all carinae covered by fine setae. Mesofemora often with an obtusely triangular sub-basal lobe two outer ventral carinae and more rarely with an additional but smaller tooth-like lobe on posterdorsal carina; sometimes a few small teeth in apical two-thirds of anterodorsal carina. Medioventral carina of meso- and metafemora well defined and with an obtuse tooth sub-apically ( Fig. 10 N-P). Metafemora alike but with sub-basal lobes. Mesotibiae with 1-2 teeth or triangular lobes in basal half of posterodorsal carina and sometimeswithan additionaltooth or triangular lobe at roughly the same position on posteroventral carina; occasionally posterodorsal with a further triangular tooth-like lobe about one-quarter off the apex or with 2-3 smaller teeth( Fig. 10 N-P). Metatibiae similar but with allthe armature much less pronounced and sometimesunarmed; only a few smallserrations present in apical portion. Basitarsi long, slender and wholly unarmed, all notably longer than remaining corresponding tarsomeres taken together.

♂ ( Fig. 10C, G-H, J-K). Medium sized for the genus (body length 107.0-115.0 mm), slender andwitha moderately globose head.General overall colour rather plain dark orange to ochre, the prothorax and legs of a slightly darker tone. Posterior margins of all abdominal terga brown. Eyes dark yellow.Antennae very dark reddish brown except for scapus and pedicellus;the scapus is coloured like the head and the pedicellus is orangey brown.

Head ( Fig. 10 J-K). –Sub-globose, about1.4x longer than wide, broadest at the eyes and strongly narrowing towards the posterior ( Fig. 10K), the vertex convex ( Fig. 10J) and smooth except for a coronal line thar is somewhat indented posteriorly. The posterior margin with a further short longitudinal indentionon each side of the coronal line. Frons with a shallow c-shaped impression above base of each antenna and area between the eyes with two shallow convex swellings. Eyes fairly large, projecting hemispherically, circular in outline and diametre of eye scarcely more than 0.5x the length of gena. Antennae with 23 antennomeres, all (except for scapus and pedicellus) much more elongate than in ♀ and roughly uniform in length, antennae about as long as head, pro- and mesothorax combined. Scapus 2.3x longer than wide, rectangular in outline and compressed dorsoventrally. Pedicellus sub-cylindrical and somewhat a little more thn one-third the length of scapus. III elongate and almost as long as the two preceding segments.

Thorax. – Pronotum basically as in ♀, shorter and narrower than head ( Fig. 10K) and with a prominently indented medio-longitudinal line in anterior half (less pronounced in posterior half). The transverse median sulcus distinct, gently curved and expanding by no more than half the width of segment. Anterior margin strongly concave, bulgy and followed by a transverse furrow, that laterally terminates in a distinct pit near each anterolateral angle of segment. Meso- and metanotum with a very fine and indistinct medio-longitudinal line and minute granulation that can only be seen with strong magnification (appearing smooth to the naked eye). Mesothorax about 3.5x longer than head and pronotum combined and 1.3x longer than metanotum; gently widened posteriorly. Metathorax widened anteriorly and posteriorly.

Abdomen. – Median segment about as long as wide with the posterior margin distinctly concave and 0.12x the its length of metanotum. Abdomen excluding median segment slightly longer than head and complete thorax combined. Segment II about 4x longer than median segment, II-V almost uniform in length and about 5x longer than wide, VI and VII notably decreasing in length with VII only 3.7x longer than wide and about threequarters the length of II-V. VII slightly widening in the posterior half. Tergum VIII about 0.6x the length of VII, distinctly widening towards posterior and trapezoidal in dorsal aspect with posterior margin some 1.6x wider than anterior margin. IX slightly shorter also trapezoidal in dorsal view and narrowing towards the posterior. Anal segment notably longer than the two preceding terga, split longitudinally ( Fig. 10H) and strongly tectiform; the hemi-terga in lateral aspect with a narrowing and shallow ventral impression post-medially, the apical portion slightly downward directed with the apex obtusely rounded ( Fig. 10G) and armed with several dark brown denticles ( Fig. 10 H-I). Cerci small, slender, gently in-curving and with the apex slightly hook-like. Poculum very small, scoop-shaped and with the posterior margin medially protruded into a triangular tooth-like appendix, which projects somewhat beyond posterior margin of tergum IX ( Fig.10G, I).

Legs. – All very long, slender and wholly unarmed except for a single, small and obtuse sub-apical denticle on medioventral carina of meso- and metafemora and a few minute denticlesin apical portionof all outer carinae of metatibiae. Profemora almost 1.5x longer and mesofemora slightly longer than head, pro- and mesothorax combined, metafemora almost reaching to posterior margin of abdominal segment VI and metatibiae projecting strongly beyond apex of abdomen. Basitarsi all very much elongated, slender and considerably longer than the remaining tarsomeres taken together.

Variability. – Females show considerable variability in the armature of the meso- and metafemora and tibiae, which is described above. All lobes and teeth vary in size and shape but the most considerable variability is seen in the dorsal sub-basal lobe of the mesotibiae, which is either a single triangular tooth but in extremes is much elongated with a median indention and two points. The sub-basal teeth or lobes of meso- and metafemora are almost completely lacking in some specimen. Some variability is also seen in the shape of the cephalic lobes, which range from rather broad and obtusely rounded to having the apical portion slenderer and pointed. The chromatic variability is summarized above. No noteworthy variability is seen in ♂.

Eggs ( Fig. 16 A-B): Fairly large, elongate and about 4.25x longer than high, strongly flattened laterally and much higher than wide. Capsule in lateral aspect slightly narrowed towards the anterior and weakly constricted pre-anteriorly with polar area unevenly indented; in dorsal aspect somewhat thickened medially. Entire capsule surface uneven, densely and minutely granulose and sparsely set with irregularly dispersed low wart-like swellings. The posterior portion distinctly verrucose. The lateral surfaces with a distinct but irregularly shaped, elongate impressed area in posterior portion and a medio-longitudinal furrow in anterior one-third, that gradually terminates slightly above the micopylar plate. Dorsal and ventral surfaces each with a very blunt and rounded medio-longitudinal bulge, which is on both sides marked by a slender and shallow A -E. Colour varieties. F. Detail of terminalia during copulation, showing how ♂ grasps the opercular organ of ♀. G. Detail of head and pronotum of a green specimen.

furrow. Micropylar plate fairly large and bilobed, consisting of two oval portions that expand almost half way over the lateral surfaces. Micropylar cup a distinct and obtuse knob-like swelling that is placed in the posteromedian gap of the plate. Median line short but distinct and bulgy. Operculum oval, impressed in centre and with a moderately raised, crenulated outer rim, that is somewhat more protruded dorsally. Colour fairly plain greyish with the warty swellings orangey ochre, micropylar plate slightly darker than capsule. Rim of operculum dark orange at the tip.

Measurements [mm]:

Length (including operculum) 8.5-8.9,

length 8.4-8.8,

width 1.3,

height 2.0-2.1,

length of micropylar plate 1.6-1.8.

Comments. – In its natural habitat specimens were predominantly found on Macaranga sp. (Anarcadiaceae). In captivity in Indonesia guava ( Psidium guajava , Myrtaceae ) is readily accepted as an alternative food plant.

Distribution. – Apparently endemic to the Island of Morotai.