Ph.D

The study entitled ‘Shining leaf beetles of south India (Coleoptera, Chrysomelidae, Criocerinae)’ was carried out at College of Agriculture, Vellayani from March 2022 to March 2025, with the major objectives of collection and documentation of shining leaf beetles and the associated ecological data; preparation of descriptions and illustrations including that of genitalia; and provide an illustrated key to south Indian species of Criocerinae. The study area comprised the states of Kerala, Tamil Nadu, Karnataka and Goa.
One thousand four hundred and fourteen specimens belonging to 42 species in four genera were studied. Detailed descriptions and illustrations of the dorsal, ventral and lateral habiti, frontal view of head, male and female genitalia including everted internal sac of aedeagus or endophallic sclerites are provided. Measurements and pertinent ratios were worked out. An illustrated key to four genera and 41 species of south Indian Criocerinae and a checklist are provided. Detailed morphological descriptions, measurements and photographs of the genitalia of south Indian Criocerinae are given for the first time.
Prior to this study, host plant information was available for all the five Indian genera of criocerines; however, at the species level, the same was known for only 14 (11.80%). The present study has added host plants of 13 species of criocerines. These include Crioceris fasciatipennis Jacoby and Lilioceris sp.1 on Smilax zeylanicus L. (Smilacaceae), Lema constrictofasciata Jacoby, Lema fulvula Lacordaire, Lema horni Weise, Lema maindroni Jacoby, Lema nilgiriensis Jacoby, Lema paradoxa Jacoby, Lema signatipennis Jacoby on Commelinaceae, Lema quadripunctata (Olivier) on Costus speciosus (Koenig) (Costaceae), Lema yerburyi Jacoby on Orchidaceae, Lema palpalis Lacordaire, and Lilioceris sp. 2 on Dioscorea sp. (Dioscoreaceae). The study has added three new country records including L. cribricollis Weise, L. westwoodi Jacoby and L. horni Weise from Kerala and 6 new records for south India, including L. cardoni Jacoby, L. constrictofasciata Jacoby, L. flavimana Jacoby,L. suturella Baly, L. jansoni Baly and Oulema downesi (Baly).
A research article on the redescription of the economically important pest species Lema yerburyi Jacoby infesting orchids in south India and its biology was published from this study. Its developmental period from egg to adult ranged from 19 to 24 days, with an egg period of 2–5 days, larval period of 5–9 days and pupal period of 10–14 days. The adults lived for 68– 187 days. The host plant of Lema quadripunctata is Costus speciosus (Koenig) (Costaceae). Eggs were laid on tender leaves near the whorls of the pseudostem and the hatching larvae bored into the stem and fed from within, creating tunnels and destroying the growing apical region. Pupation took place in soil. Adults fed on unfurled leaves, making characteristic incisions on the lamina. Field collected beetles lived for 148–156 days in captivity.
One hundred and nineteen criocerines are listed for India and 55 for south India. Of the 55 known south Indian species, 37 were recovered in this study. Lema sp. 1, Lema sp. 2, Lilioceris sp. 1 and Lilioceris sp. 2 are putative new species.