Browsing by Author "Akshaja Suresh"

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    Identity, morphology and natural history of lema species (Coleoptera: Chrysomelidae: Criocerinae) infesting orchids (Asparagales: Orchidaceae) in India
    (Department of Agricultural Entomology, College of Agriculture , Vellayani, 2021-12-21) Akshaja Suresh; Prathapan, K D
    The present study entitled “Identity, morphology and natural history of Lema species (Coleoptera: Chrysomelidae: Criocerinae) infesting orchids (Asparagales: Orchidaceae) in India” was conducted at the College of Agriculture, Vellayani from 2019-2021 to ascertain identity of the Lema species (Coleoptera: Chrysomelidae: Criocerinae) infesting orchids in India and describe them; and study the immature stages as well as lifecycle of Lema sp. infesting orchids in south India. The orchids in north-east India are attacked by Lema pectoralis unicolor Clark, distributed in China and the Indo-Malayan subregion. The Lema beetles attacking orchids in south India (Kumari and Lyla, 2001) and the Andaman and Nicobar Islands (Baskaran et al., 2016; Bharathimeena, 2016) belongs to a new species, here named as L. vimala n. sp. This is the first report of L. pectoralis unicolor in India. The beetles infesting south Indian orchids were collected from different orchid farms in Thiruvanathapuram. It was reared under laboratory conditions and the life cycle was studied in detail. The external morphology of Lema pectoralis unicolor and Lema vimala n. sp. was studied, illustrated and descriptions were prepared. The male and female genitalia of both the species were dissected, studied and photographed. Endophallus of L. vimala n. sp. was fully everted and the endophallic sclerites were studied and illustrated. Illustrations and descriptions of egg, and final instar larvae as well as pupa were prepared. The duration of life cycle ranged from 19 to 24 days, with egg period of 2 to 5 days, larval period of 5 to 9 days and pupal period of 10 to 14 days. The adults lived for 68 to 170 days. Other biological observations such as feeding and breeding behavior were also recorded. Eggs were found only on flowers and the grubs fed only on flowers while the adults fed on flowers, epiphytic roots and leaves. The grubs carry fecal shield on their back. Egg cannibalism by first instar grubs was recorded. Adults perform thanatosis. Pediobius sp. on eggs, Tetrastichus sp. nr julis on larva, and an unidentified Ichneumonidae on pupa were the parasitoids recorded on L. vimala n. sp.
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    Shining leaf beetles of south India (Coleoptera, Chrysomelidae, Criocerinae)
    (Department of Entomology ,College of Agriculture ,Vellayani, 2025-10-08) Akshaja Suresh; Prathapan, K 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.