Odonates, one of the ancient most insect groups have always stayed in the point of interest of many biologists because of their unique kind of wing pattern and flight ability, exclusively carnivorous and predatory feeding habit and mostly because of their amphibiotic life history.
The larvae probably have become aquatic secondarily as they indicate terrestrial origin, presumably to escape the interspecific competition for space and food. The respiratory, predatory feeding behavior and concealment techniques of the larvae make them more interesting to study.
Study of Indian Odonates started long back when Linnaeus (1758) described Neurobasis chinensis (though from a Non-Indian specimen) followed by Rhyothemis variegata in 1763. Later Fabricius, Rambur etc. gradually added several species to the Indian list.
 |
N. Annandale (Founder of Zoological Survey of India). Laidlaw (1920) described the larvae of Megalestes major, Rhinocypha unimaculata and Anotogaster sp. from North East India. Then a remarkable knock was made by Tillyard (1921), the description of Epiophlebia laidlawi from Darjeeling, for which adult was unknown for many years. Later Fraser added more descriptions Rhinocypha sp. in 1920, Heliocypha bisignata in 1921, Chlorogomphus atkinsoni in 1923 and Euphaea fraseri in 1929. Fraser (1928) studied Anisopleura subplatystyla but represented only in figure. The excellent compilation work Fauna of British India: Odonata by Fraser (1933, 1934 and 1936) also included larvae of several species but many of them were only in figures. Lieftinck (1940) contributed description of five Dragonfly species viz. Macromia zeylonica, Burmagomphus pyramidalis, Megalogomphus ceylonicus, Ictinogomphus rapax and Anax immaculifrons and Fraser (1943) again contributed with four more species viz. Protosticta mortoni, Caconeura gomphoides, Disparoneura apicalis and Caliphaea confusa. Knowledge about larvae of few species including Epiophlebia laidlawi were later added by Asahina (1958, 1961a & 1961b), Lieftinck (1956, 1962) and Svihla (1962). After almost another decade St. Quentin (1970) described larvae of two species and Dr. Arun Kumar started working on larval stages of odonates in Dehra Dun valley. Eventually Kumar (1970, 1971a, 1971b, 1971c, 1972a, 1972b, 1973a, 1973b, 1973c, 1973d) described larval stages of about 40 species including 21 new descriptions which included several species of genera such as Elattoneura, Pseudagrion, Ceriagrion, Agriocnemis, Ischnura, Bayadera, Burmagomphus, Paragomphus, Anax, Cordulegaster etc. and many libellulid species such as Potamarcha congener, Orthetrum Sabina, O. bruneum, O. taeniolatum, O. pruinosum, Acisoma panorpoides, Diplacodes trivialis, Trithemis festiva, T. aurora, Pantala flavescens, Trame basilaris and Zyxomma petiolatum. By the time Sangal & Kumar (1970a, 1970b), Kumar (1977, 1980, 1981, 1984a, 1984b, 1984c), Kumar and Prasad (1977a, 1977b, 1977c, 1977d, 1978), Kumar and Negi (1989) contributed with description and life history studies of several species from India. Ultimately Kumar and Khanna (1983) published a review on larval studies of odonates in India stating that almost 102 species larvae were known, but contained several flaws indeed. Later Prasad and Varshney (1995) and Kumar (1997) spared some effort on larval studies of few odonata species. Within last 20 years throughout the world study of Odonata larval stages has got some revolutionary contributions from Terence de Foneska (2000) on Sri Lankan odonata fauna; Okudaira et al. (2005) for odonates of Japanese archipelago; Theischinger (2009) for the Australian odonates and Heckman (2006, 2008) for South American odonates, but there is no such comprehensive work available in India so far. In recent years Bedjanic (2000), Bedjanic and Salamun (2002), Nesemann et al. (2011) studied larval stages of odonates from Indian subcontinent. Xu Ql-han (2009) described Macromia flavocolorata [from China]; Das et al. (2013) found Lyriothemis tricolor larvae to breed in Phytotelmata; Takhelmayum & Gupta (2014) studied some larvae from Manipur and Xu Qi Han (2015) described Heliocypha perforata with a revision of larvae the genus. Dawn (in press) studied larvae of 21 species from Chhattisgarh including Gynacantha millardi. So, till date larvae of about 100 species of Odonata is reported. Some of them have detailed description and some are known only with photographs. Other than the taxonomic studies some behavioral studies are also done in last few years. Begum et. al. (1992) described the emergence patterns of Tholymis tillarga, Neurothemis tullia tullia, Diplacodes nebulosa, Crocothemis servilia servilia and Ictinus sp. in Ramna Lake of Bangladesh. Biswas et. al. (1994) examined the emergence pattern of Brachythemis contaminata, Tholymis tillarga, Crocothemis servilia servilia Diplacodes trivialis, Orthetrum pruinosum neglectum and Ictinus angulosus from Bangladesh. Kumar (1989) studied the emergence pattern of Pantala flavescens in relation with the monsoon in India. Kumar and Negi (1989) reported the emergence and sex ratio of Bradinopyga geminata and Crocothemis servilia servilia at Dehra Dun Valley, India. Mitra (1998) studied the emergence behaviour of Trithemis festiva in laboratory condition at Dehra Dun, India. Further details of emergence of Pantala flavescens was studied by Andrew & Patankar (2010). It is clear that only 20% of the Indian Odonata are known in there larval stages and more extensive studies are needed to explore the knowledge about the larvae, their habitat preferences, seasonal abundance and more importantly effect of climate change and pollution over them. Due to their carnivorous feeding habit odonates are very important insect group as biological control measure for the insect pests (Khaliq, 2002). The larval stages are equally important as potential bioindicator (Catling, 2005) and to control mosquito larvae as well (Stav et al., 2000). Toxicological studies using odonata larvae are still lacking in India though being a part of our freshwater food-chain they may hold an important role in Biomagnification.
