Revision of the legume-feeding leaf beetle genus Madurasia Jacoby, including a new species description (Coleoptera, Chrysomelidae, Galerucinae, Galerucini)

Abstract Madurasia Jacoby is revised and Madurasia andamanica sp. n., endemic to the Andaman Islands in the Indian Ocean, is described and illustrated. Madurasia obscurella Jacoby, syn. n., is a new junior synonym of Madurasia undulatovittata (Motschulsky), comb. n. A lectotype is designated for Madurasia obscurella. Literature on the biology and management of Madurasia undulatovittata is reviewed.


Introduction
The monotypic galerucine genus Madurasia was described by Jacoby (1886) for a new species, Madurasia obscurella, from southern India. Aslam (1972) synonymized Neorudolphia bedfordi Laboissière, 1926, the only species in this monotypic genus from Sudan, with M. obscurella Jacoby. Examination of the type of Monolepta undulatovittata (Motschulsky 1866) (originally described in Teinodactyla Chevrolat = Longitarsus Latreille) from Sri Lanka has shown that Madurasia obscurella is a junior synonym of Motschulsky's species. The genus is here revised and a new species is described from callosity protruding slightly laterally, setigerous pore laterally situated. Disc without impressions, shiny, uniformly punctate, punctures small, smaller than those on elytra.
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.
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.
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.
Paratypes ( Distribution. India (Andaman Islands) (Fig. 34). Remarks. Color pattern in M. andamanica sp. n. (Fig. 21) appears to be consistent and less variable compared to that in M. 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 M. undulatovittata externally. However, it can be distinguished based on the structure of the aedeagus and the number of labral setae, as described under M. undulatovittata.
Paralectotype ♀. "Type / H. T." (white circular disc with red border); "Madura"; "Jacoby Coll. 1909-28a."; "Madurasia / obscurella / Jac. Type" (Blue label); "SYN-TYPE" (white circular disc with sky blue margin); "Paralectotype / Madurasia obscurella Jacoby / des. K. D. Prathapan, 2015" (BMNH).  13°25'48"N, sent); elytral stripes are highly variable in M. undulatovittata, even in specimens from the same locality, collected during the same season and on the same host. The elytral pattern in M. andamanica sp. n. is rather consistent. The stripe in M. undulatovittata is wider apically in specimens where it is well defined, while in M. andamanica sp. n., it is narrowed apically. In M. andamanica sp. n., the stripe is distinct and well defined against the pale background color. Verma (1995) recorded variation in elytral color pattern. Lobe in the middle of the posterior margin of the apical abdominal ventrite in males distinct in M. andamanica sp. n., but poorly distinguishable in M. undulatovittata. The two species can easily be separated by the structure of the aedeagus. In lateral view, the apex of aedeagus of M. andamanica sp. n. is curved and pointed, like the beak of a parrot (Fig. 26), while the same in M. undulatovittata is narrowly rounded, and smoothly curved in apical 1/3 (Fig. 27). The sharply raised ridge on the ventral aspect of the aedeagus in M. andamanica sp. n. (Fig. 24) is characteristic, however, this ridge is absent in M. undulatovittata (Fig. 25). Madurasia andamanica sp. n. is confined to the Andaman Islands and reported to feed on pigeon pea, while M. undulatovittata is transcontinental in distribution and a significant pest of a number of species of pulses in southern Asia and Africa (Sudan).
A photograph of the labels provided by Wagner & Bieneck (Fig. 38a in Wagner and Bieneck 2012) shows three labels, two of which show different information for M. undulatovittata (Fig. 2). Labels currently on the specimen indicate that M. Döberl designated the lectotype in 2005. However, no publication by Döberl could be traced in which this specimen is mentioned. According to Wagner and Bieneck (2012), the lectotype was designated by Wagner, and they provide photographs of both the lectotype and its labels. The photograph (Fig. 38b) in Wagner and Bieneck (2012), confirms that the specimen examined by me is the one designated as lectotype by Wagner (Fig. 1). Moreover, Wagner and Bieneck (2012) also mention that the only other specimen, a paralectotype in Motschulsky's collection, is a male from which the aedeagus has been dissected and subsequently lost. Dr Wagner's lectotype designation stands valid as that alone is published (Wagner and Bieneck 2012). Dr Döberl designated the same specimen as lectotype in 2005 as there was a long gap of nearly a decade between the lectotype designation by Dr Wagner and the publication of the same in Wagner and Bieneck 2012 (T. Wagner and M. Döberl, pers. comm., 2016). The specimen collected by Bedford on 22.ix.1923, identified as Neorudolphia bedfordi by Laboissière from the BMNH, probably belongs to the type series of N. bedfordi. The lectotype for M. obscurella is here designated, to have a unique name bearer and standard for its application. Biology and management. Information on the host plants and biology of M. undulatovittata was generated by agricultural entomologists in India, under the name M. obscurella, where it is a widely distributed pest of legume crops across many agro climatic zones. The first record of this species as a pest of pulses is that by Menon and Saxena (1970). According to Naresh and Thakkur (1972), it was reported as a major pest of black gram by Naresh and Nene in 1968. However, there is no mention of this leaf beetle in Naresh and Nene (1968). Saxena et al. (1971) described it as a pest of cowpea, green gram or moong and black gram or urd, indicating that it made holes in the leaf lamina. Other recorded host plants include Glycine (CAB International Institute of Entomology 1990), moth bean (Pareek et al. 1983), lablab bean (Gupta and Singh 1984a, b), pigeon pea (Saxena 1977, Mishra andSaxena 1983), rice bean (Satyanarayana et al. 1995a, b) and Vigna radiata (L.) Wilczek var. sublobata (Roxb.) (=Phaseolus sublobatus Roxb.) (Kalaichelvan and Verma 2005).  Gupta and Singh (1984a, b) provided the first account of its life cycle. They recorded the total life cycle as varying between 32 and 44 days and that it completes two generations a year on green gram. A second, more detailed study of the life history was reported by Oza et al. (1996) on cowpea. Eggs were laid singly on soil near the root zone of the plant. The total duration of the life cycle, from egg to death of adult, varied between 35 and 48 days in males and 43 to 58 days in females.
The growth of plants is retarded by severe foliage injury, especially in young plants (Srivastava and Singh 1976). Leaf damage on green gram in summer and rainy season crops ranged between 5-10% and 15-50% respectively . Larvae are soil dwelling and feed on root hairs (Srivastava and Singh 1976;Gupta and Singh 1981). Odak and Thakur (1978) reported larval feeding on the root nodules. Gowda and Kaul (1982) recorded adult feeding on leaves, buds and flowers. Gowda et al. (2006) also observed feeding damage by adults on the buds and flowers of pigeon pea. Reddy and Varma (1986) established transmission of southern bean mosaic virus in cowpea by M. undulatovittata. The success in transmission varied from 25 to 43%.
The extent of damage on black gram, green gram and cowpea was 20-60% (Srivastava and Singh 1976). This is a common pest of mung bean in the first crop season (kharif) in India, coinciding with the southwest monsoon (June to October) (Tiwari 1978). Singh and Gupta (1982) estimated damage to the leaves of green gram and black gram. Infestation was more pronounced in black gram than in green gram. Infestation starts when the plants are in the two leaf-stage and the insects remain active until flowering Singh 1983, Nayak et al. 2005).
In Haryana, Yadav and Yadav (1983) recorded it from cowpea and Mrig and Singh (1985) observed maximum damage on D. lablab during the third week of September, with the pest disappearing after the first week of November. Feleiro and Singh (1985) carried out yield-infestation studies to fix the critical stages of crops requiring protection. They observed that infestation in summer resulted in heavy yield losses, while the pest attack during the rainy season had no significant effect on yield. Lal (1985) reviewed information on the biology and control of insect pests of mung bean, including M. undulatovittata, in India.
According to Faleiro et al. (1986), M. undulatovittata is a sporadic, but major pest of cowpea. A peak population of 10.0-10.25 beetles/10 plants in summer and 29.50-30.25 beetles/10 plants in the rainy season were recorded by Gupta and Singh (1993) in green gram. Sahoo and Patnaik (1994) recorded the incidence of insect pests in green and black gram, and their seasonal activity and the extent of damage in Orissa. Madurasia undulatovittata was severe on both the crops in the seedling and vegetative stages, and was the first pest to appear at seedling stage on rice bean, continuing to occur until flowering (Satyanarayana et al. 1995b). Ganapathy and Durairaj (1995) reported it as an important pest on black gram and green gram in drought prone Pudukottai District, Tamil Nadu. There was more damage in black gram (9.78%) than in green gram (1.45%). However, there are also reports of M. undulatovittata only being a minor pest (Devesthali andJoshi 1994, Kumar et al. 1998). Dhuri et al. (1984) observed population buildup of M. undulatovittata under ambient temperature of about 32°C, longer duration of bright sunshine and high relative humidity coupled with intermittent rainfall. Sardana and Verma (1986) showed that maximum temperature and sunshine were negatively, but significantly, correlated with the population of the pest, while rainfall showed a significantly positive correlation. Maximum temperature, minimum temperature, sunshine hours and wind velocity had a significantly negative correlation with damage (Irulandi and Balasubramanian 1999). Nayak et al. (2004) reported a significantly negative correlation with minimum temperature and relative humidity during population buildup on black gram. The population did not show any correlation with maximum temperature, relative humidity and rainfall, but it was highly and significantly correlated with minimum temperature (Kumar et al. 2007).
Various cultivars of green gram (Srivastava et al. 1975, Sahoo et al. 1989, Sahoo and Hota 1991 and black gram (Sahoo et al. 1989) vary significantly in their susceptibility to the pest. Pandey et al. (1995) reported that varieties with thicker leaves were preferred by the pest.

Discussion
A revision of the genus Medythia is required to define the boundaries between it and the genus Madurasia. Medythia and Madurasia share the same ecological niche and are often collected together on the same host plants, as well as at light. It is likely that economic entomologists have often misidentified one for the other. Medythia bukit and Medythia marginicollis, described by Mohamedsaid (1999) from Malaysia, with pronotum broader than wide, as well as a little narrower anteriorly than posteriorly, appear atypical for the genus. Reports of a 6.05mm, ovate beetle as M. obscurella from Pakistan ) are incorrect.
Madurasia andamanica sp. n. is a significant pest of red gram or pigeon pea (C. cajan) in the Great Andaman Islands (Bharathimeena T., pers. comm. 2015), similar to the pest status of M. undulatovittata elsewhere. This endemic pest of the islands, in case of accidental introduction to the mainland India, is likely to become a pest of various pulses and spread far and wide, as in the case of M. undulatovittata.