Phaelota vaishakha, Prathapan, K. D. & Viraktamath, C. A., 2004

Prathapan, K. D. & Viraktamath, C. A., 2004, Revision of Phaelota Jacoby (Coleoptera: Chrysomelidae) with descriptions of three new species, Zootaxa 447, pp. 1-18 : 14-16

Phaelota vaishakha , new species

( Figs. 26–35 )

Distribution. India (Kerala).

Host plants.? Christella sp. ( Thelypteridaceae ), Microlepia speluncae (L.) Moore ( Dennstaedtiaceae ) and Stenochalaena palaustris (Burm.) Bedd. ( Stenochlaenaceae ).

Description. Colour variable. Reddish brown with varying shades of black on dorsal side ( Figs. 24, 25 ) and hind femora. Sometimes sternites also tainted black. Five distal antennomeres always black. Two specimens resemble P. sindhoori in colour: entirely reddish brown except five distal antennomeres that are black. In general elytron black with a reddish patch in middle, pronotum reddish with a black patch along posterior margin. One specimen has reddish elytron with four black spots including one on humerus. Anterior pronotal callosity, labrum, clypeus, first antennomere sometimes yellowish brown.

In lateral view proximal end of frons slightly higher than vertex. Margin of vertex with frontal calli distinctly depressed. Vertex moderately flat, minutely punctate. Area surrounding supraorbital pore depressed. Antennal calli transverse, highly convex, narrowly separated from each other, low along margin with vertex. Midfrontal depression extremely short and narrow hence appears as if absent. Frontal ridge without median longitudinal carina. Frontal ridge proximally distinctly convex and punctate. Maxillary palpus with preapical palpomere longer than half of apical.

Third antennomere distinctly longer than second; fourth subequal to or slightly longer than third; fifth subequal to fourth or slightly shorter; sixth slightly shorter than fifth, not distinctly thicker than fifth; seventh longer and thicker than sixth; eighth shorter than seventh; eighth to tenth subequal in length; eleventh two times as long as tenth; width of tenth antennomere more than half of its length.

Pronotum distinctly narrower proximally than distally. Lateral margin strongly curved. Anterolateral callosity moderately low, forming blunt obtuse denticle at pore. Disc shiny, covered with small punctures distinctly larger than those on vertex. Antebasal transverse impression with punctures stronger than those on rest of pronotum. Scutellum shiny, extremely minutely punctate, wider than long, apex widely rounded. Elytron with well developed humeral callus, with depression posteriorly, maximum width at proximal 1/4. Interstices flat with a mixture of small to moderate sized punctures. Width of interstices subequal to 4–6 times diameter of a puncture. Epipleuron horizontal, not reaching apex.

Metatibia apparently straight in lateral view; slightly curved from dorsal view; distal half dorsally flat, rest of surface convex. Claw subequal to metatibial spur in length. Ridge along mesal edge of metafemur in male with a denticle in middle followed by emargination, serrulation not prominent ( Fig. 34 ).

Last abdominal sternite of male with a rectangular lobe in middle of posterior margin ( Fig. 26 ). In ventral view median lobe of aedeagus widened at distal 1/3, apex conical, lateral margins slightly emarginate preapically; ventral side moderately convex ( Fig. 27 ). Distal 2/3 nearly straight in lateral view ( Fig. 28 ). Dorsal opening partially covered by two laminae ( Fig. 29 ). Arms of tegmen slightly shorter than stem ( Fig. 30 ). Receptacle of spermatheca subeqaul to pump in length, internal and external sides moderately convex; oblong, longer than wide with maximum width below middle. Pump with horizontal part longer than vertical. Pump and receptacle not differentiated by distinct rim. Duct nearly twice as long as receptacle, not coiled, forms loop away from receptacle ( Fig. 31 ). Medial margin of vaginal palpus narrowed at distal 1/3; proximal sclerotization lighter than distal sclerotization, both subequal, shorter than unsclerotized area in middle. Posterior sclerotization not emarginate at apex. Lateral margin does not form angle with medial margin ( Fig. 32 ). Tignum slightly curved and narrowed proximally. Sclerotized part of apex slightly widened ( Fig. 33 ).

Measurements (all values in mm; n=10). Length 3.40–5.00 (4.13); width 2.68–3.95 (3.26); length of pronotum 1.05–1.75 (1.3); width of pronotum 2.20–3.00 (2.46); width across eyes 1.10–1.50 (1.25); distance between eyes 0.53–0.69 (0.58); distance between antennal sockets 0.17–0.22 (0.19); length of aedeagus 1.9; length of vaginal palpus 0.80; length of receptacle 0.18.

Types. Holotype ɗ. Labels 1) India: Kerala Ponmudi 10.V.2003 Prathapan Coll. 2) Phaelota vaishakha sp. nov. Prathapan & Viraktamath, 2003 3) Holotype (BMNH). Paratypes: 8ɗ, 6Ψ. The same data as holotype (1 NHMB, 5 PKDC, 4 PNC, 2 UASB, 2 USNM).

Etymology. Date of collection of the types according to the Saka era is 20th Va is h akha, 1924 and hence the name.

Remarks. Phaelota vaishakha closely resembles P. sindhoori . Colour in P. vaishakha is variable and some specimens are coloured exactly like P. sindhoori . But they can be separated based on the following characters. In lateral view, frontal ridge joins vertex at a higher level in P. vaishakha while in P. sindhoori they are in the same plane. P. sindhoori has a distinct midfrontal depression reaching well below the level of antennal sockets while midfrontal depression is extremely short and appears as if absent in P. vaishakha . Frontal calli are transverse in P. vaishakha (oblique and longer than wide in P. sindhoori ). In P. vaishakha , the sixth antennomere is not distinctly thicker than fifth while in the other three species the sixth antennomere is distinctly thicker than the preceding one. Aedeagus of P. vaishakha (distinctly widened at distal 2/ 3 in ventral view) is distinct from that of P. jacobyi and P. sindhoori (not widened at distal 2/ 3 in ventral view) and the distal end is covered by two laminae (covered by a single lamina in P. jacobyi and P. sindhoori ). P. vaishakha resembles P. semifasciata especially in the shape of the antennal calli which is wider than long and strongly curved lateral margin of prothorax. But P. vaishakha can be separated from P. semifasciata based on the well developed humeral callus (humerus is flat in P. semifasciata ) and lack of carina along middle of frons (carina present in P. semifasciata ).

Figures

FIGURES 24 – 35. Phaelota vaishakha. 24 & 25, variation in elytral pattern; 26, last abdominal sternite of male; 27, median lobe of aedeagus, ventral view; 28, median lobe of aedeagus, lateral view; 29, median lobe of aedeagus, dorsal opening; 30, tegmen; 31, spermatheca; 32, vaginal palpi; 33, tignum; 34, metafemur of male, ventral view; 35, metafemur of female, ventral view.