Lanka aruna, 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 : 6-8

Lanka aruna New species

( Figs 4–12 , 54)

Distribution. India (Kerala).

Host plants. Piper trioicum Roxb. (Piperaceae) ( Figs 62, 63).

Description. Head, pronotum, elytron, sternites bright brick red. General color of antennae and legs piceous; labrum, basal two or three antennomeres, apex of last antennomere, distal one or two tarsomeres dark brown. All coxae, trochanters reddish brown. Distal palpomere of maxilla and apex of all femora brown.

Vertex minutely punctate with a few moderate sized punctures. In lateral view, out line of vertex and frons forms a straight line. Supraantennal sulcus slightly weaker than supracallinal sulcus. Antennal callus dis- tinctly high near post callinal sulcus than near supraantennal sulcus. Anterofrontal ridge with a denticle in middle. Labrum with middle two setiferous pores being closer to each other than to lateral ones. Antenna reaches proximal 1/3 of elytron. Antennomeres 3–6 subequal, seventh distinctly longer than sixth; 8–10 each slightly shorter than preceding one; tenth subequal to sixth; 11 th slightly longer than first, distinctly longer than tenth; fourth onwards antennomeres thickened, distal 5–6 antennomeres distinctly wider than first antennomere.

Pronotum uniformly punctate with lateral margin anteriorly wider than posteriorly. Anterolateral callosity convex, slightly longer than 1/3 of lateral margin including anterolateral callosity. Posterolateral callosity with one or two minute setae on ventral side. Prosternum 1.5 times longer than width of intercoxal prosternal process, length of prosternum 3.0 times distance between anterior margin of prosternum to procoxal cavity. Intercoxal prosternal process with raised rim along posterior as well as lateral margins, distally depressed with a ridge in middle. Mesoscutellum wider than long, minutely punctate. Mesosternum 0.6 times longer than width of intercoxal part, length of mesosternum 1.3 times distance between anterior margin of mesosternum to mesocoxal cavity. Mesosternum appear highly depressed as flat on top with sharply raised lateral and posterior margins. Metasternum 2.4 times longer than prosternum. First protarsomere in female ventrally with long setae different from those on dorsal side. Elytra with maximum width in proximal 1/3, punctures semi-regular, two lateral rows distinct, rest uncountable; distance between punctures of adjacent rows in middle of elytron 1–4 times diameter of a puncture. Metatibia straight in lateral view, gradually widening from proximal end to distal 3/4, slightly narrowing there after, widest point being nearly two times as wide as proximal end; in dorsal view, maximum width at distal 1/4, dorsal surface convex in proximal 1/6, about flat till middle, gradually becoming concave thereafter with callosity distally. Lateral margin higher than mesal margin in middle 1/3. Second metatarsomere shorter than half of first, slightly shorter than two times length of third; claw tarsomere about two times as long as third. All metatarsomeres together slightly longer than metatibia. Longitudinal ridges on first abdominal ventrite reach up to half of its length, diverge in middle, slightly converge distally ( Fig. 4 ).

Spermathecal pump with horizontal part about two times longer than vertical, narrowing to apex, apex hooked, widest at proximal 1/3. Receptacle 3.5 times longer than wide, slightly shorter than two times length of pump, widest near pump, gradually narrowing towards duct, outer side concave, inner side convex, duct forms acute angle with receptacle, nearly three times as long as receptacle, folded twice ( Fig. 11 ). Vaginal palpi appear separate in dissection, slightly more sclerotised along mesal margin which is widest proximally, narrowing towards apex, curved, medial margin concave in distal 2/3, transversely wrinkled proximally ( Fig. 10 ). Tignum with posterior sclerotization wider towards posterior margin ( Fig. 12 ). Aedeagus robust, slightly widened near posterior 1/ 3 in ventral view; with acute, distinctly recurved apex in lateral view ( Figs 6–8 ).

Measurements (n=5). Length: 3.23–3.57 (3.37), width: 2.05–2.24 (2.15), length of pronotum: 0.91– 1.01 (0.93), width of pronotum: 1.41–1.60 (1.47), width across eyes: 0.91–1.03 (0.97), transverse diameter of one eye: 0.32–0.33 (0.33), distance between eyes: 0.41–0.47 (0.45), distance between eye and antennal socket: 0.03–0.05 (0.04), distance between antennal sockets: 0.10–0.19 (0.15), diameter of one antennal socket: 0.10– 0.12 (0.11), length of aedeagus: 0.51, length of receptacle: 0.16, length of vaginal palpi: 0.40.

Types. Holotype ♂. Labels 1) INDIA: Kerala: Ponmudi 10.V.2003 Prathapan Coll. 2) Lanka aruna sp. nov. Prathapan & Viraktamath, 2005 3 ) Holotype ( BMNH) .

Paratypes (4 specimens). 2♂, 2 ♀. Arippa, 8.ii.2004 (Prathapan) (1 PKDC, 1 PNC, 1 UASB, 1 USNM) .

Etymology. ‘Aruna’ means red in Malayalam, the language spoken in the state where the type locality is situated, and refers to the color of the species. The species name is a noun in apposition.

Diagnosis. This distinct species can be differentiated from the other Indian species by its red dorsum and black antenna. Antenna in L. aruna is thicker and reaches 1/3 of elytron when extended over pronotum (thin and longer in the other two species). Antennal calli are rather transverse in L. aruna while they are obliquely placed in the other Indian species. Frontal ridge in L. aruna is wider between antennal sockets and the vertical carina on anterofrontal ridge is indistinct compared to other species. Transversely wrinkled vaginal palpi and a robust aedeagus are the other distinct features of this species.

Remarks. L. aruna is also the largest species of the genus in India and is probably confined to the lower reaches of Agasthyamalai hills located at the southern end of Western Ghats ( Fig. 67 ) where endemism is frequent ( Nayar, 1996).

Figures

FIGURE 67. Distribution of Lanka spp. in India.

FIGURES 4–12. Lanka aruna. 4. intercoxal ridges on first abdominal ventrite; 5. male last abdominal ventrite; 6. aedeagus, ventral view; 7. aedeagus, lateral view; 8. distal opening; 9. tegmen; 10. vaginal palpi; 11. spermatheca; 12. tignum.