Ph.D

The present study entitled “Chaetocnema species of south India (Coleoptera, Chrysomelidae, Galerucinae, Alticini)” was carried out at the College of Agriculture, Vellayani from September 2019–September 2024. The study was designed with the objectives of collection and identification of Chaetocnema species from south India, documentation of host plants and other ecological data in all possible cases, preparation of illustrations and descriptions, with emphasis on characters of the male and female genitalia and preparation of an illustrated key to species. The study area encompasses the states of Kerala, Tamil Nadu, Karnataka, Goa and Andhra Pradesh. Two thousand six hundred and fifty-two specimens belonging to 29 species from south India were studied. Detailed descriptions and diagnosis with color photographs of dorsal, ventral and lateral habiti as well as other diagnostic characters, including male and female genitalia, were prepared. Relevant measurements and proportions were worked out. An illustrated key to Chaetocnema species of south India is provided. Three putative new species are described and illustrated. These were collected from Kollam and Malappuram districts in Kerala and Madurai district in Tamil Nadu. Type specimens of ChaetocnemanagpurensisDuvivier, 1892 are lost and hence a neotype is designated for nomenclatural stability. Male genitalia of C. reteimpunctata and female genitalia of C. appendiculata, C. paraumesaoi, C. latapronota and C. westwoodi are newly described and illustrated. Eighteen new host plants are recorded: C. puncticollis on Celosia argentea L., Amaranthusspinosus L., A. viridis L., A. dubius Mart. ex Thell, Alternantheratenella var. bettzichiania (Regel) Veldkamp, Allmanianodiflora (L.) R. Br. Ex Wight (Amaranthaceae), Basella sp. (Basellaceae); Spinaciaoleracea L. (Chenopodiaceae); C. bella on Panicumsumatrense Roth. Ex Roemer and Schultes, Cynodondactylon Pers., Oryzasativa L., Eleucineindica (L.) Gaertn., Brachiariadistachya (L.) Stapf, Brachiariamutica (Forssk.) Stapf, (Poaceae); C. gracilis and C. yiei on Oryzasativa L., C.brettinghami, C. concinnipennis on Cynodondactylon Pers. (Poaceae), and C. angustifrons on Brachiariamutica (Forssk.) Stapf (Poaceae), C. modesta on Setariahomonyma (Steud.) Chiov., Eleucineindica (L.) Gaertn., Cynodondactylon Pers., Oryzasativa L. and Brachiariamutica (Forssk.) Stapf (Poaceae). The following are new records for India: C. kingpinensis from Meghalaya and Manipur, C. yunnanica from Manipur, C. tristis from Meghalaya, C. angustifrons from Kerala and Tamil Nadu and C. reteimpunctata from Kerala. Taxonomic significance of labrum and characters of the elytralepipleura in Chaetocnema were discovered and used during this study. Angle of articulation of labrum with the long axis of the body was found to be a species-specific character. Epipleura are punctured in: C. puncticollis, C. bella, C. bretinghami. C concinnipennis, C.malayana, C. paraumesai, C. pusaensis, C. reteimpunctata (shallow punctures), C. westwoodi, Chaetocnema sp. 2, Chaetocnema sp. 3, C. nigrica, C. latapronota and C. midimpunctata. In all other species epipleura are impunctate.