International Journal of Entomology Research 11 International Journal of Entomology Research ISSN: 2455-4758 Impact Factor: RJIF 5.24 www.entomologyjournals.com Volume 2; Issue 6; November 2017; Page No. 11-15 The juvenile hormone mimic, pyriproxyfen, increases the level of the major haemolymph protein in the larvae of Spodoptera mauritia Boisd. Lepidoptera: Noctuidae Resmitha C, Dr. Kannan Vadakkadath Meethal Department of Zoology, University of Calicut, Thenjipalam (PO), Malappuram, Kerala, India Abstract Insect Growth Regulators (IGR's) belong to a group of compounds which interfere with normal growth, development and reproduction in insects by disrupting hormonally regulated physiological processes of insects. Pyriproxyfen is an IGR which mimics the action of Juvenile Hormone (JH). The influence of IGRs on haemolymph protein profile of lepidopteran pests is not well characterized. Exposure of 5 th instar larvae of S.mauritia to sub lethal concentration (LD10) of pyriproxyfen led to an increase in size of the larvae. Concomitantly haemolymph protein concentration of the treated larvae also increased compared to control. In pyriproxyfen treated larvae, on SDS-PAGE, there was an increase in the intensity of the predominant haemolymph protein band (83kDa) indicating a specific effect of pyriproxyfen on this protein. The pyriproxyfen-responsive protein is a glycoprotein and is synthesized/ stored in fat body. The identified pyriproxyfen-responsive protein is likely to be a member of hexamerins, the major storage protein in the haemolymph of insects. Keywords: JH-analogue, insect growth regulator, pyriproxyfen, protein profile 1. Introduction The rice swarming caterpillar, Spodoptera mauritia Boisd. (Lepidoptera: Noctuidae) also known as paddy army worm is a sporadic pest distributed all over the world. In India, earlier it was considered as a minor pest of rice but for the last one decade, it has emerged as serious pest of rice seedlings. In India it is found in all the rice growing areas especially along the west coast and delta in Kerala and Tamil Nadu [1] . Pest management is an integral part of any successful agriculture. Application of conventional insecticides poses great threat to the human health and environment. Insect Growth Regulators (IGR's) belong to a group of compounds which interfere with normal growth, development and reproduction in insects by disrupting hormonally regulated physiological processes of insects. Insect growth regulators adversely affect insect growth and development. Several such compounds are known and their effects on metamorphosis and reproduction in a number of insect species have been extensively studied [2, 3, 4] . Insect growth regulators are more selective in their mode of action and thus less toxic to non- target organisms. An IGR does not necessarily have to be toxic to its target, but instead they may lead to various abnormalities that impair insect survival [5] . Many of the IGRs are mimics of insect hormones, juvenile hormone (JH) or ecdysone. Pyriproxyfen is an IGR which mimics the action of JH. Advantages of IGRs includes species specificity, less or zero toxicity to other animals, fast penetrance through the insect cuticle and they get degraded to non toxic compounds in a short time period. Already around 500 analogues with JH activity have been discovered. Among the well known juvenile hormone analogues (JHAs) are, Epofenonane, Methoprene, Hydroprene, Kinoprene, and Phenoxy carbamate [6] . The first JHA of commercial success were Methoprene and Hydroprene [7] . Methoprene is active against dipteran insects and fleas and hydroprene is active against cockroach. These compounds however, were too unstable under field conditions to be used in agriculture. The photostable JH analogue, fenoxycrab was effective not only on household pests but also on agricultural pest such as leaf rollers, the codling moth and Psylla pyricola. [8] Pyriproxyfen is a juvenile hormone analog with relatively low mammalian toxicity that was registered in Japan in 1991 for controlling public health pests [9] . Timely application of JHs could be employed to control insects because of their ability to disrupt normal physiological functions [10] . Pyriproxyfen mimics the action of JH and maintains the insect in an imma- ture state which inhibit the successful molting of the insect or normal reproduction [11] . Most common morphogenetic effect of JHA treatment is the production of extra larval, nymphal or pupal form. The formation of extra larval instar depends on stage and age of the larvae at the time of treatment. Pyriproxyfen is a commonly used insect growth regulator against homopoteran insect pests, including whiteflies [12, 13] . The utility of pyriproxyfen in whitefly management was demonstrated based on suppression of embryogenesis and adult formation in Bemisia tabaci (Gennadius) [14] and Trialeurodes vaporariorum [14] . Protein metabolism plays a very important role in rebuilding adult structures during the transformation of larvae/pupae into adult. In general hemolymph protein levels increase during each instar but decline during moulting. In haemolymph typically two to four physicochemically distinct storage protein species occur. Storgae proteins of insects such as hexamerins are also involved in transport of hormones, phenols /or some cuticular proteins to the hypodermis. In holometabolous insects, active synthesis of arylphorins