Madurasia andamanica, Prathapan, Kaniyarikkal Divakaran, 2016

Prathapan, Kaniyarikkal Divakaran, 2016, Revision of the legume-feeding leaf beetle genus Madurasia Jacoby, including a new species description (Coleoptera, Chrysomelidae, Galerucinae, Galerucini), ZooKeys 597, pp. 57-79 : 61-63

Taxon classification Animalia Coleoptera Chrysomelidae

Madurasia andamanica sp. n. Figs 21, 22, 24, 26, 28, 30, 32, 33

Diagnosis.

The new species can be recognized by the following characters: 1) elytral stripe not reaching the elytral apex, narrowing in distal 1/4; 2) labrum with a transverse row of eight well developed setae; 3) posterior margin of apical ventrite in male distinctly lobed medially; 4) apex of aedeagus in lateral view curved like a parrot’s beak with an acute tip; 5) ventral side of aedeagus depressed in basal 1/2, then distally raised in the form of a narrow ridge which reaches the apex.

Description.

Body: length 2.1-2.6 mm; width 1.1-1.2 mm; 1.8-2.1 times longer than wide (Fig. 21). Dorsum straw colored. Head dark brown. Antenna with basal three or four antennomeres a pale straw color, distal antennomeres becoming progressively darker. Mandible, maxilla, and labium paler than labrum and anterior aspect. Pronotum with pale orange hue. Elytra a pale straw color, the dark elytral stripe not reaching the elytral apex (Fig. 21), widest anteriad of middle, narrowing distinctly posterior of humerus as well as in distal 1/4. Thoracic sternites and pronotum concolorous, metathoracic sternite often a slightly darker laterally. Abdominal ventrites pale brown, with lateral margins and apical abdominal ventrite darker in many specimens. Legs straw colored, tibia and first two tarsomeres often a slightly darker than femur. Antenna reaching slightly beyond middle of elytron. Proportionate length of antennomeres 1-11: 1: 0.48: 0.45-0.50: 0.63-0.67: 0.63: 0.61-0.62: 0.66-0.67: 0.62-0.70: 0.63-0.69: 0.62-0.63: 0.75-0.88. Transverse diameter of eye 6.3-8.0 times width of orbit, 3.3-3.8 times width of interantennal space, 1.7-1.9 times width of antennal socket, 0.7 times distance between eyes. Pronotum 1.2-1.3 times wider than long, posterior width 1.1-1.2 times wider than anterior width.

Proportionate length of femur:tibia:tarsomeres 1-4 as follows: 1: 1.0-1.1: 0.2-0.3: 0.2: 0.1-0.2: 0.2-0.3 (foreleg); 1: 0.9-1.0: 0.3: 0.1-0.3: 0.1-0.2: 0.2-0.3 (midleg); 1: 1.0-1.1: 0.4: 0.1-0.2: 0.1: 0.2 (hindleg).

Posterior margin of apical ventrite in male distinctly lobed medially (Fig. 22). Receptacle of spermatheca 2.4 times wider than long (Fig. 28). Tignum widened proximally; membranous apex wider towards posterior (Fig. 32).

Aedeagus in lateral view (Fig. 26) with greatest width near middle, narrow in proximal 1/4, apex curved like a parrot’s beak with an acute tip. In ventral view (Fig. 24), greatest width at base, narrowing abruptly in apical 1/3; ventral aspect depressed in basal 1/2, then distinctly raised in the form of a narrow ridge which reaches the apex.

Etymology.

Named after the Andaman Islands, where the new species occurs.

Material examined.

Holotype ♂ "INDIA: Andaman & Nicobar / North Andaman: Diglipur / 13°14'53.9"N, 92°58'37.5"E, / 15 mts. 24.iv.2014. At light / Yeshwanth H. M." (white label); "HOLOTYPE / Madurasia andamanica / Prathapan sp. nov., 2015" (red label) (BMNH).

Paratypes (104). 5♂, 8♀ same data as holotype; 7♂, 19♀ same data as holotype, but 23.iv.2014; 2♀ INDIA: Andaman & Nicobar / South Andaman: Sippighat / 11°67'26"N, 92°67'12"E, / 44 mts. 18.iv.2014, Light trap / Yeshwanth H. M.; 1♂, 16♀ India: South Andaman / Garacharama / 12.xi.2014 / Bharathimeena Coll. / Ex Redgram; 16♂, 7♀, 1 unsexed same data but 8.I.2015; 2♂, 20♀ same data but 4.XII.2014 and collector Krishnaveni (5 BMNH, 5 USNM, 5 JBC, 5 KAU, 5 UASB, 40 NBAIR, 39 INPC).

Distribution.

India (Andaman Islands) (Fig. 34).

Remarks.

Color pattern in Madurasia andamanica sp. n. (Fig. 21) appears to be consistent and less variable compared to that in Madurasia undulatovittata (Motschulsky, 1866), where the color of specimens collected on the same host at the same locality on the same day varied greatly. Madurasia andamanica sp. n. resembles Madurasia undulatovittata externally. However, it can be distinguished based on the structure of the aedeagus and the number of labral setae, as described under Madurasia undulatovittata .

Host.

Cajanus cajan (L.) Millsp. ( Fabaceae ) (red gram or pigeon pea) (Bharathimeena T., pers. comm. 2015).