Madurasia Jacoby, 1886

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 : 58-61

Taxon classification Animalia Coleoptera Chrysomelidae

Madurasia Jacoby, 1886

Madurasia Jacoby, 1886: 280 (Type species: Madurasia obscurella Jacoby, 1886, southern India, by monotypy)- Maulik 1936: 72- Wilcox 1973: 435- Seeno and Wilcox 1982: 107- Jolivet and Hawkeswood 1995: 101 (host plants)- Medvedev and Sprecher–Uebersax 2005: 316 (key)- Beenen 2010: 481.

Neorudolphia Laboissière, 1926: 190 (Type species: Neorudolphia bedfordi Laboissière, 1926, Sudan, by monotypy)- Wilcox 1973: 435- Aslam 1972: 500 (= Madurasia Jacoby 1886: 280).

Description.

Body: length 2.0-3.0 mm; 1.8-2.3 times longer than wide. Moderately small, oblong, flattened in lateral view, length 3.1-3.4 times height. General color straw brown to dark brown with a characteristic, more or less distinct, dark, broad longitudinal stripe on each elytron (Figs 1, 3, 5-7, 21); mesal margin of stripe nearly straight; each stripe nearer to suture than to lateral margin of elytron; stripe narrowing laterally posteriorly of humerus and in distal 2/3 of elytron.

Head (Fig. 8) hypognathous with frontal view slightly longer than wide. In lateral view anterior margin forms a moderately convex line with a notch where vertex meets antennal calli and a second notch at anterior end of frontal ridge. Supraorbital pore represented by a large setaceous pore adjacent to orbital sulcus near eye. Seta in supraorbital pore upcurved. Vertex shiny, indistinctly wrinkled, nearly impunctate. Antennal calli trapezoidal, longer than wide, moderately convex, raised above adjacent border of vertex, separated from each other by a deep midfrontal sulcus; anterior ends acutely triangular, enter into interantennal space, reaching well below midlevel of antennal socket. Orbital sulcus short, deep, represented by supraorbital pore and adjacent area. Supracallinal sulcus represented by punctures arranged in an irregular transverse row, each puncture in supracallinal row bearing a short down-curved seta. Midcranial suture absent. Supraorbital sulcus less distinct than midfrontal sulcus. Suprafrontal and supraantennal sulci well defined. Subgenal suture distinct. Transverse diameter of eye 5.2-8.8 times distance between eye and antennal socket, 2.9-4.4 times distance between antennal sockets, 1.7-1.9 times width of antennal socket, 0.6-0.7 times distance between eyes. Eyes lateral, medium sized, convex, inner margins indistinctly concave, and ventrally divergent. Frontal ridge narrowest between antennal sockets, joins anterofrontal ridge anteriorly. Anterofrontal ridge transverse, gently curved. Frontal ridge together with antero-frontal ridge forms T–shaped ridge. Anterofrontal ridge lower than frontal ridge. Frontolateral area coarsely punctate, each puncture bearing a long seta. Frontoclypeal suture with a row of eight setae. Clypeus narrow. Visible part of labrum much wider than long, with a transverse row of eight pores; all eight pores in Madurasia andamanica sp. n. with a well-developed seta; while only six pores, excluding third pore from either end, with seta in Madurasia undulatovittata . Labrum (Fig. 13) with anterior margin incised medially; about seven sensillae on either side of incision, arranged along anterior margin of labrum’s inner surface; tormae longer than width of labrum. Mandible (Fig. 12) palmate with six sharp denticles. Maxilla (Fig. 11) with four palpomeres: first shortest, second and third subequal, both longer than first, but shorter than apical palpomere, apical longest; lacinia wider than galea. Labial palpi (Fig. 10) with three palpomeres, basal two wider than long, middle widest, apical palpomere longer than wide and longest of three. Antenna (Fig. 9) reaches more or less middle of elytron. First antennomere longest, club shaped; second smallest; third a little longer than second; fourth distinctly longer than third; 4-10 subequal in length; eleventh longer than all except first antennomere; five to six distal antennomeres wider than preceding three or four (Fig. 9).

Dorsum glabrous. Pronotum (Fig. 14) 1.2-1.3 times wider than long; greatest width slightly anterior of middle. Posterior margin 1.1-1.2 times wider than anterior margin, lateral margin gently convex, posterior margin nearly straight in middle, curved laterally, and narrowly margined. Anterolateral callosity longer than wide, setigerous pore posterolaterally situated, not forming denticle at pore; posterolateral callosity protruding slightly laterally, setigerous pore laterally situated. Disc without impressions, shiny, uniformly punctate, punctures small, smaller than those on elytra. Anterior coxal cavity open behind (Figs 4, 16); intercoxal prosternal process short, acutely pointed, not reaching midlevel of procoxa (Fig. 16); procoxae longer than wide and closely associated; shortest distance from anterior margin of prosternum to procoxal cavity about 1/4-1/5 of longitudinal procoxal diameter. Mesoscutellum triangular, about two times wider than long, flat, impunctate to minutely punctate. Intercoxal mesosternal process short, not reaching midlevel of mesocoxa (Figs 4, 17). Mesepisternum broader than mesepimeron (Fig. 17). Metasternum no longer than first two abdominal ventrites combined (Fig. 4).

Elytra broader than pronotum basally, maximum width posterior of middle. Humeral callus well developed; elytral border narrow, becoming indistinct towards apex; elytral apex broadly rounded; epipleuron (Fig. 4) oblique, maximum width near anterior 1/4 of elytron, maximum width subequal to about 1.5 times maximum width of mid-femur, narrows abruptly before middle and then continues very narrowly, becoming indistinct towards the elytral apex. Hind wings present. Metanotum (Fig. 15) well developed with full complement of internal ridges.

All femora oblong in cross section; all tibiae subcylindrical, subcircular in cross section with a minute apical spur; metatibial spur subequal to claw in length; proportionate length of femur–tibia–tarsomeres 1-4 as follows: 1: 1.0-1.1: 0.2-0.3: 0.1-0.2: 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: 1.1-1.2: 0.4: 0.1-0.2: 0.1: 0.2 (hindleg); joint where metatibia and first metatarsomere meet, black; third tarsomere always bilobed; claws simple and appendiculate, appendix small and basal. Abdomen (Fig. 4) with five distinct ventrites; ventrites 2-4 becoming progressively slightly shorter; fifth ventrite slightly longer than fourth; intercoxal projection of first abdominal ventrite acute; apical abdominal tergite (Fig. 19, 20) without a median longitudinal groove, posterior margin slightly concave medially in male of Madurasia undulatovittata (Fig. 20) and distinctly emarginate in Madurasia andamanica sp. n.; posterior margin of apical tergite broadly convex (Fig. 19) in females of both species; posterior margin of apical ventrite more or less lobed medially in male (Figs 22, 23), entire in female.

Female genitalia with receptacle of spermatheca (Figs 28, 29) pot-shaped, wider than long; pump curved, longer than receptacle and enlarged distally, appendix well developed; spermathecal duct shorter than receptacle, glandular duct beyond middle of spermathecal duct. Tignum (Figs 32, 33) gently curved near middle, grooved medially, with long setae near distal margin of broad membranous apex. Vaginal palpi (Figs 30, 31) fused from proximal end to a short distance beyond middle, separate distally, each palpus narrowing towards rounded apex, lateral margin concave preapically, with long distal setae. Median lobe of aedeagus strongly curved in lateral view (Figs 26, 27), acutely pointed. Tegmen with stem much longer than arms.

Host plants.

Fabaceae .

Distribution.

Asia, Africa (Sudan).

Remarks.

Madurasia closely resembles Medythia Jacoby, 1887, and species of both genera are pests of legumes. The general morphology, including the structure of the head, female genitalia, and even the presence of elytral stripes in some species of Medythia , are similar to those in Madurasia , making differentiation of these genera difficult. Madurasia can be separated from Medythia by the structure of the pronotum. The pronotum in Medythia is elongate and narrows posteriorly, whereas the pronotum is transverse and a little wider posteriorly in Madurasia . The elytral epipleuron is short in Madurasia , hardly extending beyond middle of the elytron. In Medythia quadrimaculata Jacoby, type species of the genus, the elytral epipleuron is longer, extending beyond the middle of the elytron. However, the epipleura are identical to those of Madurasia in a few Indian Medythia species examined. In Madurasia , the distal antennomeres are darker, while antennomeres 8-10 are whitish in most Medythia species, including the type species.

Adults are attracted to light.