Phaelota semifasciata Jacoby

Prathapan, K. D. & Viraktamath, C. A., 2004, Revision of Phaelota Jacoby (Coleoptera: Chrysomelidae) with descriptions of three new species, Zootaxa 447, pp. 1-18 : 8-10

Phaelota semifasciata Jacoby

( Figs. 12–14 )

Phaelota semifasciata Jacoby, 1887 , 94. Syntype Ψ Sri Lanka [BMNH, examined]; Maulik, 1926, 176, 280; Heikertinger & Csiki in Junk, 1940, 511; Scherer, 1969, 218.

Distribution. Sri Lanka (Jacoby, 1887).

Host plants. Unknown.

Description. General colour reddish brown. Elytron with dark brown broad outer band and two inner narrow stripes which become indistinct posteriorly. Pronotum almost piceous, margins and middle longitudinal stripe reddish brown. Last six antennomeres dark brown.

Frons and vertex form almost a straight line. Vertex sparsely punctate, moderately flat, slightly depressed behind antennal calli. On each side, adjacent to anteromesal region of supraorbital puncture, one more puncture present. Antennal callus broader than long, transverse, high near border with antennal socket than near border with supracallinal sulcus. Midfrontal depression shallow, not passing below lower border of antennal sockets. Frontal ridge sparsely minutely punctate with a narrow, slightly raised carina along middle in anterior half. Carina forms a denticle in middle of anterofrontal ridge. Maxillary palpus with preapical palpomere as long as half of apical.

Antennomeres second, third, and fourth subequal in length. Fifth slightly longer than fourth; sixth thicker but slightly shorter than fifth. Seventh slightly longer and thicker than sixth. 7–11 thicker than sixth. 7–9 subequal in length, tenth slightly shorter than ninth. Tenth two times as long as wide. 11th 1.4 times as long as 10th.

Pronotum slightly narrower proximally than distally. Lateral margins strongly curved. Anterolateral callosity low, forming a blunt obtuse denticle at pore. Disc shiny, covered with small punctures. Punctation in antebasal transverse impression not stronger than that on rest of pronotum. Scutellum wider than long, widely rounded at apex, extremely minutely punctate.

Elytron with humeral callus poorly developed with a somewhat longitudinal depression on mesal side of humerus, without depression posteriorly. Maximum width at anterior 1/3. Surface shiny, punctures small, shallow, indistinct posteriorly. Interstices flat, minutely punctured. Lateral sides moderately flat. Width of interstices 3–5 times diameter of a puncture. Elytral punctures indistinct beyond 2/3. Epipleuron oblique, reaching apex.

Metatibia nearly straight in lateral view, very slightly curved in ventral view. Dorsal surface flat in distal 3/5, rest of it convex.

Receptacle of spermatheca longer than pump, internal side more convex than external side, oblong, about 2.5 times longer than wide with maximum width below middle. Pump with horizontal part longer than vertical. Pump and receptacle not differentiated by a rim. Pump apically widened. Duct shorter than receptacle, bent at an acute angle before middle ( Fig. 12 ). Vaginal palpus with anterior sclerotization shorter than posterior sclerotization. Apex somewhat transparent, posterior sclerotization not emarginate at apex. Sides narrowed preapically, apex widened, rounded and lateral margin not forming angle with medial margin ( Fig. 13 ). Tignum slightly curved, widened proximally, narrowed preapically, sclerotized part of apex slightly widened ( Fig.14 ).

Measurements (all values in mm; n=1). Length 5.00; width 3.15; length of pronotum 1.25; width of pronotum 2.30; width across eyes 1.40; distance between eyes 0.77; distance between antennal sockets 0.31; length of vaginal palpus 0.97; length of receptacle 0.14.

Type specimens examined. Phaelota semifasciata . Syntype Ψ. Labels: 1) Ceylon G. Lewis 1910­320; 2) Bogawantalawa 4900–5200 ft 21.III–4.IV.82 (=1882); 3) Phaelota semifasciata Jac. ; 4) Right hind leg mounted in balsm S. Maulik 1929; 5) 114/82; 6) Examined & dissected K. D. Prathapan 2003 ( BMNH).

Remarks. P. semifasciata is very distinct from the three Indian species in having flat humerus without a posterior depression (humeral callus is well developed with a posterior depression in the three Indian species), second antennomere as long as third (third antennomere is distinctly longer than second in the other three species) and the median longitudinal carina that forms a denticle in the middle of the anterofrontal ridge (median longitudinal carina is absent in P. sindhoori and P. vaishakha , though present, it does not form a denticle in P. jacobyi ). Distal antennomeres in the Indian species are much thicker than those in P. semifasciata . Transverse diameter of the antennal sockets is also less in P. semifasciata compared to others.

Figures

FIGURES 12 – 14. Phaelota semifasciata. 12, spermatheca; 13, vaginal palpi; 14, tignum.