Lilioceris cheni Gressit & Kimoto, 1961

Tishechkin, Alexey K., Konstantinov, Alexander S., Bista, Sanjay, Pemberton, Robert W. & Center, Ted D., 2011, Review of the continental Oriental species of Lilioceris Reitter (Coleoptera, Chrysomelidae, Criocerinae) closely related to Lilioceris impressa (F.), ZooKeys 103, pp. 63-83 : 65-67

Lilioceris cheni Gressit & Kimoto, 1961 Figs 16, 814, 2123, 24

Lilioceris cheni Gressit & Kimoto, 1961: 46 (type locality: SE China Fukien, E. Kwangtung. Type depository: BBM).

Diagnosis.

Occipital area with a shallow furrow, at least with a deep small fovea at mid-point. Apical elytral punctures strong. Pronotal disc with scattered larger punctures, mid-line alignment of punctures usually evident, at least in anterior half. Pronotum posteriorly with single weak, irregular, variable, transverse impression. Lateral sides of pronotum around constriction with large punctures. Outer metasternal disc almost completely covered with setae. At least half of metepisternal disc covered with setae. Apical elytral intervals distinctly raised. Internal sac of aedeagus with posterior part of dorsal sclerite in dorsal view more or less parallel-sided, directed medially. Posterior part of dorsal sclerite in lateral view more or less parallel-sided, bent ventrally, directed ventrally.

Comments.

The holotype of Lilioceris cheni is housed in the Bishop museum collection. This collection contains 5 more specimens of this species all identified as Lilioceris cheni by Kimoto in 1967 and 1977, none of them are marked as paratype.

Biology.

Pale white, oblong eggs of Lilioceris cheni are deposited in loosely aggregated clusters on leaves of its host plant, Dioscorea bulbifera (air potato: Dioscoreaceae ). Females deposit, on average, more than 1200 eggs during their lifetime. The eggs become yellowish as the embryo develops and dark reddish eye spots appear mid-way through the incubation period. The entire incubation period requires about 4 days. The larvae are yellowish at first, becoming grayish in later instars, with black legs, head capsule, and prothoracic shield. They are often covered with a slimy substance to which fecal material adheres. Larvae feed gregariously and skeletonize the leaves from the underside. Young leaves are preferred but they also consume older, tougher leaves and are able to feed on the aerial bulbils. Complete development of the four larval instars requires about 8 days, with each instar lasting about 2 days each. When fully grown, larvae drop from the host plant to the soil which they quickly enter. They then produce a whitish oral exudate that hardens into a foam-like cocoon. Pupation often occurs gregariously, with several pupae clumped together within a matrix of this material. Adults emerge in about 16 days, begin mating in about 10 days following emergence, and initiate oviposition about 5 days later. The adults live 3 months or more and can survive a month without food.

In the Katmandu Valley of Nepal, the host plant drops its leaves during the cool, dry winter forcing the adult beetles to over-winter beneath debris on the ground. The adults emerge during mid-May to early June. Oviposition begins during late May and continues till mid-June. Females lay about 90 eggs/day during a 13-day period of ovipositional activity. Overwintered adult beetles live until mid-July, for about 76 days after emergence.

Type material examined.

Lilioceris cheni : Holotype male: 1) Fukien, S. China, Shaowu city to Kaoyang, T. C. Maa Coll.; 2) July 30, 1945; 3) Holotype Lilioceris cheni J. L. Gressitt + K.; 4) L. cheni sp. n. Det. S. Kimoto (BBM).

Material examined.

CHINA.Yunnan: Ma-Chang, 1000 m, 1 specimen (USNM); Tche-Ping-Tcheou, 1 specimen (USNM); 13-18.X.2010, RCVDIPRL 25. Oct. 10, M. Percell (USNM). INDIA. Indie orientales, 1 specimen (USNM). Assam: Chabua, 8.V.1944, G. Butler, 1 specimen (USNM). LAOS.Sayaboury Prov., Sayabouri, 30.V.1965, native collector, 1 specimen (BBM); Vientianne Prov., Vientianne, 21.IV.1965, J. A. Rondon, 1 specimen (BBM). NEPAL. On road to Dhunche, 5 km SW Ranipawa, 27°48.92'N, 85°13.41'E, 1700 m, 28.IV.2000, A. Konstantinov, S. Lingafelter & M. Volkovitch, 1 specimen (USNM); Gairigaonbelow Nagarkot,Kathmandu Valley, host Dioscorea bulbifera , 27.VIII.2002, Pemberton & Rayamhji, 1 specimen (USNM); Env.ofKathmandu, Palchoki Mount, 27°34.65'N, 85°24.04'E, 2300-2730 m, sweeping, 14.V.2000, A. Konstantinov, S. Lingafelter & M. Volkovitch, 1 specimen (USNM); Lalitpur, Kathmandu, 4.VIII.-15.X.2007, Yukawa & Junichi, 29 specimens (USNM); Seutikhola Dharan road, Sunsan, host Dioscorea bulbifera , 4.IX.2002, Pemberton & Rayamhji, 1 specimen (USNM); Tarai Reg., Narayangarh, along Rapti River, 27°42.31'N, 84°21.11'E, beating, 26.IV.2000, A. Konstantinov, S. Lingafelter & M. Volkovitch, 1 specimen (USNM).