Pachyrhynchus ilgas, Rukmane, 2017

Rukmane, Anita, 2017, New Species Of The Genus Pachyrhynchus Germar (Coleoptera, Curculionidae, Entiminae) From The Greater Mindanao Pleistocene Aggregate Island Complex (Philippines), Acta Biologica Universitatis Daugavpiliensis 17 (1), pp. 85-95 : 86-88

Pachyrhynchus ilgas sp. nov. ( Figs. 1C , 2 , 7 )

Type material. Holotype: Male ( DUBC) ‘’ PHILIPPINES, Visayas, Samar Island , Lope De Vega , II. 2017, / local collector leg. /’’ (typed on white card); ‘’ex. Prof. A. Barševskis coll.’’ (typed on white card) ; ‘’ HOLOTYPE / Male / Pachyrhynchus ilgas / Rukmane, 2017 / det. Rukmane Anita, 2017’’ (typed on red card).

Distribution: Philippines (Eastern Visayas region: Samar Island) ( Fig. 7 ).

Description. M a l e. Dimensions: LB: 15.6. LR: 2.4. WR: 2.05. LP: 4.3. WP: 4.95. LE: 9.3. WE: 6.25. N = 1 for all measurements. Dorsal habitus as shown in Fig. 1C .

Integument glossy, coppery brown; antennae black; tarsi coppery brown with green tingle. Body surface mostly strongly shiny, except antennae and underside with weaker luster.

Rostrum, pronotum, elytra and profemur with shiny pale green markings of round recumbent scales, depending on light exceptive scales have blue luster.

Head dorsaly subglabrous, minutely pubescent; eyes relatively large, moderately prominent from outline of head; outline of each eye highest behind middle; antennae short and stout, scape shorter than funicle, strongly clavate; funicle with segment I more than twice as long as wide, 1.3 times as long as II; segment II 1.5 times as long as wide, twice as long as III; segments III-V subequal in length, slightly wider than long, narrower than segment VI, segment VI slightly wider than long, segment VII 1.8 times as long as wide, club shaped; forehead with narrow linear scaly patch on middle; lateroventral parts below eyes densely covered with pale green markings of round and elliptic scales and short pale hair-like scales. Rostrum minutely pubescent, longer than wide (length/wide 1.17) with profound triangular concavity on basal half, weakly bulging on apical half; linear scaly patch on middle of basal half, connected basally with patch on forehead; lateroventral parts behind antennal scrobes minutely covered with pale green scales and long golden hairs.

Prothorax subglabrous, wider than long (wide/ length 1.15), maximum transverse diameter in middle, finely punctured, with the following two scaly markings: from base of each lateral side of pronotum to median part of disc, sharply interrupting on apex and gradually interrupting on base; anterolateral and posterolateral angles without scaly markings; weak basal impression. Elytra short ovate, striate-punctate, widest just before middle, convex dorsally, wider than prothorax (elytral/pronotal width 1.26), more than twice longer than prothorax (elytral/pronotal length 2.16); two following scaly markings: 1) from lateral margin of each elytron huge transverse band in parallel to base connecting in median part, with triangular imprint without scaly markings on interval I and II reaching half width of transverse band, 2) large band from median part of elytra to apex, with T shaped area without scales from apical 3/5 till apex, one horizontal line from middle of interval VIII of each elytron and second vertical line at interval I, extending gradually to interval II at apical part. Coxae densely covered with pale scales on anterior parts. Profemur minutely pubescent, with roundish scales on basal parts along posterior margins forming irregular patch on subapical part. Tibiae with moderate fine hairs and darker setae on interomarginal and apical parts, hairs become longer apically.

Genitalia as illustrated in Fig. 2 . Sternite IX slender, nearly 1.5 times as long as aedegal body, slightly curved leftward. Aedegal body stretched out, in lateral view moderately curved ventrally in the subbazal part, and gradually attenuated in the apical part, apex with angle-shaped ventral margin, curvature raised dorsally and sharply incurved ventrally at middle; two prominent bulges near base of ostium. In frontal vision widest at base, gradually narrowed at apical plate.Aedegal apodemes slender, neatly 2.4 times shorter than aedegal body. Tegmen with slender apodeme, nearly twice as long as diameter of tegminal ring.

Female unknown.

Diagnosis. Pachyrhynchus ilgas is related to P. absurdus Schultze, 1919 known from Mindanao, but P. ilgas is distinguishable from it by it’s wider pronotum and elytra with characteristic scaly markings ( Fig. 1C ). Sutural apex is rounded, less peaked. Superior 1 st and 2 nd metatarsomere. Clypeus without slight dent in central part. Characteristic shape of male genitalia ( Fig. 2 ). Species also shows similarity in body pattern and shape of male genitalia to P. orientalis sp. nov. described from Mindanao Island, but is distinguishable by characteristic scaly markings, shape of male genitalia, brighter body color, rostrum with weaker apical bulge. Species might be confused with P. samarensis Schultze, 1923 by it’s similarities of scaly markings and distribution, but according to unique shape of male genitalia, species is more close related to ‘ ’ absurdus ’’ group.

Etymology. Species is named after Daugavpils University study and research center ‘’Ilgas’’, where is located one of the biggest collections of genus Pachyrhynchus , accumulating more than two thousands of specimens with over one hundred of detected species. Place keeps it’s mystery and is overwhelmed with peace and good atmosphere, calling any friendly company for visit.

Taxonomical notes

Pachyrhynchus ilgas sp. nov. shows morphological relationships with a small group of Pachyrhynchus species distributed within the greater Mindanao Pleistocene Aggregate Island Complex ( PAIC), which includes Samar, Leyte, Bucas Grande and mainland Mindanao ( Fig. 7 ). This group is called ‘ ’ absurdus ’’ species group. Initially P. absurdus belonged to ‘’ speciosus ’’ species group created by Schultze ( Schultze 1923), but on the basis of highly divergent morphological characters, new division is required. The species of this group share the following combination of morphological characters:

1. Integument glowing red, coppery or black, marked with pale green to orange scale stripes and bands;

2. Eyes weakly convex from outline of head;

3. Rostrum in basal half with an oblong triangular shallow depression;

4. Two curves in apical part of rostrum, size of curves species specific;

5. Linear scaly patch from forehead to median part of rostrum;

6. Elytra elongated, with strongly extended apex;

7. Phallobase of aeadeagus increased and curved following: curvature raised dorsally and sharply incurved ventrally at the middle.

Figures

Fig. 1. Dorsal habitus of A- P. occidentalis, male; B – female; C – P. ilgas, male; D – P. orientalis, male; E – female; F – P. neoabsurdus, female.

Fig. 2. Male genitalia of P. ilgas. A – aedegal body in lateral view; B – aedegal body in frontal view; C – sternite IX; D – tegmine. Scale 1mm.

Fig. 7. Distribution map of Pachyrhynchus ‘’absurdus’’ group.