Lanka ramakrishnai, Prathapan & Viraktamath, 2008

Prathapan, K. D. & Viraktamath, C. A., 2008, The flea beetle genus Lanka (Coleoptera: Chrysomelidae) in India with descriptions of three new species and notes on the identity of the pollu beetle infesting black pepper, Piper nigrum, Zootaxa 1681 (1), pp. 1-30 : 9-14

publication ID	https://doi.org/ 10.11646/zootaxa.1681.1.1
persistent identifier	https://treatment.plazi.org/id/727987BB-FFBF-D316-FF11-F38AFCDDFFB3
treatment provided by	Felipe
scientific name	Lanka ramakrishnai
status	sp. nov.

Treatment

Lanka ramakrishnai New species

( Figs 13–35 View FIGURE 13 View FIGURES 14–18 View FIGURES 19–26 View FIGURES 27–35 , 55)

Longitarsus nigripennis ( Motschulsky, 1866) : Ramakrishna Ayyar, 1919 (misidentification); Maulik, 1926 (misidentification); Scherer, 1969 (misidentification).

Lanka bicolor (Chûjô) : Doeberl, 2003 (misidentification).

Distribution. India (Karnataka, Kerala, Tamil Nadu).

Host plants. P. nigrum L. ( Figs 59, 60) and P. trioicum Roxb. ( Figs 62, 63).

Description. Head, antennae, prothorax, fore and middle legs, hind tibiae and tarsi brown; under side and hind femora dark brown to shining black; scutellum brownish black, elytra shining black.

Vertex minutely punctate without moderate sized punctures. In lateral view, vertex and frons form a concave line. Supraantennal sulcus apparently stronger than supracallinal sulcus. Antennal calli slightly high near postcallinal sulcus than near supraantennal sulcus. Anterofrontal ridge with a weak vertical carina along middle. Labrum with distance between middle two setiferous pores being less than distance between lateral pairs (found to vary in a few specimens where the distance between the middle pairs equal to or more than that between lateral ones). Antenna reaches slightly beyond half of elytron; fourth antennomere slightly shorter than third; fifth to seventh subequal, slightly longer than fourth; antennomeres 8–10 each slightly shorter than preceding one; 11 th subequal to first in length, subequal to or longer than tenth; distal one or two antennomeres slightly wider than first.

Pronotum with stronger punctures posteriorly, lateral margin anteriorly wider than posteriorly. Anterolateral callosity convex, as long as 1/3 of lateral margin including anterolateral callosity. Posterolateral callosity without minute setae on ventral side. Prosternum 2.5 times longer than width of intercoxal prosternal process, length of prosternum 6.2 times distance between anterior margin of prosternum to procoxal cavity. Intercoxal prosternal process with slightly raised lateral, posterior margins, preapically with a pair of depres- sions separated by a longitudinal ridge. Mesoscutellum wider than long, impunctate, minutely granulose. Mesosternum 0.9 times longer than width of intercoxal part, length of mesosternum 2.7 times distance between anterior margin of mesosternum to mesocoxal cavity. Mesosternum with raised lateral margin, posterior margin slightly raised, depressed in middle. Metasternum 1.3 times longer than prosternum. First protarsomere ventrally with sparse, pointed, minute setae in female. Elytron with maximum width at anterior 1/3, punctures arranged in regular rows distinct till distal 3/4, distance between two adjacent rows 4–7 times diameter of a puncture in middle of disc. Metatibia indistinctly curved in lateral view, gradually widening from proximal end to slightly beyond half of it, then narrowing again. In dorsal view, maximum width at distal 1/3. Dorsal surface convex in proximal 1/4, rest of it more or less concave; lateral edge much higher than mesal edge in middle, metatibial spine slightly longer than claw, thicker than claw; second metatarsomere slightly shorter than half of first, slightly shorter than two times length of third; claw tarsomere slightly shorter than two times length of third. All metatarsomeres together slightly shorter than metatibia. Ridges on first abdominal ventrite extend beyond 2/3, converge distally, nearly parallel sided in middle ( Fig. 27 View FIGURES 27–35 ).

Spermatheca with pump smoothly curved, horizontal part slightly longer than vertical, bluntly pointed; receptacle narrowed towards duct in distal 1/4, outer side slightly concave, inner side convex, length slightly more than two times width; duct makes three s-curves not clearly visible in lateral view ( Fig. 34 View FIGURES 27–35 ); proximal 1/ 4 th of vaginal palpus narrower, curved, medial margin slightly concave ( Fig. 33 View FIGURES 27–35 ). Tignum with arrow-head shaped posterior sclerotization narrowing distally ( Fig. 35 View FIGURES 27–35 ). Aedeagus in lateral view with slightly recurved apex; in ventral view gradually narrowed towards apex in distal 1/3 ( Figs 29, 31 View FIGURES 27–35 ).

Measurements (n=10). Length: 2.28–2.71 (2.50), width: 1.45–1.73 (1.57), body length-width ratio: 1.52– 1.63 (1.59), length of pronotum: 0.73–0.88 (0.80), width of pronotum: 1.00–1.18 (1.08), width across eyes: 0.67–0.75 (0.70), transverse diameter of one eye: 0.25–0.27 (0.26); distance between eyes: 0.24–0.30 (0.27), distance between eye and antennal socket: 0.02–0.03 (0.02); distance between antennal sockets: 0.06–0.08 (0.08); diameter of one antennal socket: 0.07–0.09 (0.08), length of median lobe of aedeagus: 0.95, length of receptacle: 0.18, length of vaginal palpi: 0.27.

Types. Holotype ♂. Labels 1) INDIA Kerala Vellayani 4. vi. 2005 Prathapan Coll. 2) Lanka ramakrishnai sp. nov. Prathapan & Viraktamath, 2005 3 ) Holotype ( BMNH) .

Paratypes (92 specimens). 10♂, 6 ♀ data as for holotype , 6♂, 6♀ data as holotype except the date 4.x.2002 , 1♀ 28.x.2002, 2♂ 15.vii.2003, 6♂, 1♀ 25.v.2005; 2♂ Malabar Dt., Taliparamba, 20.ix- 4.x.-17 (=1917) (Ramakrishna); 1♂ Thekkady , 27.iii.1997 (B. Mallik) ; 3♂, 5 ♀ Trivandrum, 7. xii.1997 (Prathapan); 1♂ P. muzhy (= Peruvannamuzhy), 1.ii.1998 (Prathapan), 1♂ same data except the date 20-21.iv.2003 ; 2 ♀ Chengannur , 8. ix.1998 (Prathapan) ; 1♀ Kottarakkara, 26.xi.2000, ex. Piper nigrum (Prathapan) ; 3 ♀ Ponmudi , 29.ii. 2002 (Prathapan) , 5♂, 5 ♀ Ponmudi, 29.ix.2002, ex Piper argyrophyllum (Prathapan) ; 1♂. Ala, 15.x.2002 (Prathapan); 2♂, 2 ♀ Eramallikkara, 16.x.2002 (Prathapan); 1 ♂ Munnar Top Station , 28.xi.2002 (Prathapan) ; 1♂ Munnar-Vattayar , 29.XI.2002 (Prathapan) ; 4♂, 1 ♀ Neyyar W. L. S. (=Neyyar Wildlife Sanctuary), 12.ii.2004 (Prathapan); 2♂, 5 ♀ Periyar Tig. Res. (= Periyar Tiger Reserve ), 15.ii.2004 (Prathapan) ; 3♂ Arippa , 12.vi.2005 (Prathapan) ; 3♂ Karnataka, 18 km S.Virajpet, Brahmagiri WildLife Sanctuary, 20.XI. 2003, 303m, N12°28'20" E75°42'30" (Konstantinov, Prathapan, Saluk) GoogleMaps . (8 BMNH, 50 PNC, 5 UASB, 2 USNM, 9 NHMB, 4 KUJ, 4 EUJ, 1 LMRC, 9 PKDC)

Other material examined. 3 ♂, 1♀ Panniyoor , 1.i.1981 ; 4♂, 2♀. Kerala (No data) ( BMNH) ; 6 ♂, 1♀ Western Ghats Tamil Nadu, 35 km SW Kodaikanal, 25-26. x. 2006, 2060 m Kukal (=Kookal) Shola (Prathapan) ( PKDC) .

Etymology. This species is named after the well known pioneer Indian Entomologist, T. V. Ramakrishna Ayyar, who first discovered this species (identified for him as “ Longitarsus nigripennis ”) as a pest of black pepper and described its unique biology.

Diagnosis. Lanka ramakrishnai is distinct from all other species of Indian Lanka in having a yellowish head and pronotum and black elytra.

Remarks. T. V. Ramakrishna Ayyar, who first recorded this insect as a pest of black pepper at Taliparamba in northern Kerala in 1917, sent the specimens to the British Museum for naming (These specimens are here designated as paratypes.). G. A. K. Marshall, an authority on weevils working there, determined them as “ Longitarsus nigripennis ” based on the single sentence description by Motschulsky (1866) in French: “ A closely related but smaller species from the continent of India, T. nigripennis, Motsch. , is very remarkable for its coloration, having the head and pronotum testaceous and the elytra black”. The genus Teinodactyla Chevrolat was later synonymised with Longitarsus Latreille by Weise, 1888. The type of Motschulsky’s T. nigripennis was neither accessible to Maulik (1926), who published the monumental work on leaf beetles in the Fauna of British India series, nor to Scherer (1969) who subsequently published a monograph on the flea beetles of the Indian subcontinent. Hence, both of them continued to use the name L. nigripennis as it had already gained popularity through literature as being the pollu beetle. Maulik (1926), Scherer (1969) and Medvedev (2000a) treated it as a species mistakenly placed in the genus Longitarsus .

A study of Motschulsky’s type of T. nigripennis has ultimately led us to the correction of the misidentification of Marshall in 1917 and it is now shown that the pollu beetle infesting black pepper in south India is not “ nigripennis ”. Scherer (1969) has recorded L. ramakrishnai (as L. nigripennis ) from Assam and Tamil Nadu. Record of L. ramakrishnai outside of south India needs confirmation. Extensive field work in Sri Lanka by one of us (PKD) did not yield L. ramakrishnai , although its host plant – P. nigrum – is common in the Island. Lanka bicolor (Chûjô) recorded by Doeberl (2003) from the pepper growing tracts near Kottayam in Kerala is undoubtedly L. ramakrishnai . L. bicolor has yellowish head and reddish pronotum (both head and pronotum are yellowish in L. ramakrishnai ) and the third antennomere is only slightly longer than second (third antennomere almost two times as long as second in L. ramakrishnai ). L. bicolor has a strongly punctate pronotum and elytron. Elytral punctures are larger than half the distance between two adjacent punctures, whereas they are much smaller in L. ramakrishnai . Besides the above external features, their geographical ranges are also separate. L. ramakrishnai was collected from sea level to an altitude of 2060 m above mean sea level. At higher altitudes of about 1000 m and above, it prefers P. trioicum to P. nigrum .