Insect Fauna of Paddy in Nalgonda District of Biology of Root

4 Insect Environment, Vol.17(1), April-June 2011 Insect Environment, Vol.17(1), April-June 2011 5 Insect fauna of paddy in Nalgonda District of green leaf hopper (Nephotettix sp) and panicle mite (Steneotarsonemus Andhra Pradesh spinki Smiley) were also found causing moderate damage. The panicle mite which in recent times gained importance has already achieved status R. Muralidhar Naik and P. Rajanikanth Agricultural Research Station, Kampasagar, Acharya N.G Ranga Agricultural of major pest in the region due to its heavy economic damag. It may be University, Rajendranagar, Hyderabad - 500 030, India due to the favourable climatic conditions i.e high temperatures existing in the region. Gall midge, Orseolia oryzae, Woodmason incidence was Rice is grown in an area of 10 lakh hectares in Nagarjuna Sagar project found to be very negligible in the region but its incidence was observed command area of Nalgonda district of Andhra Pradesh (South India). under late transplanted conditions particularly when there is delay in Inspite of the cultivation of high yielding rice varieties the average yield of release of water from the project. Paddy leaf folder, Cnaphalocrocis rice per hectare in the area is still very low. Among the various constraints medinalis Guenee was observed during the months of September and in low land rice production, the damage due to large number of insect October, but its damage was found to be low in the region. Rice hispa, pests right from sowing in nursery till the harvest of the crop is substantial. Dicladispa armigera Olivier, and whorl maggot, Hydrellia phillipina Ferino An attempt has been made to study the insect fauna associated with rice were noticed rarely and was found to cause low damage. The minor pests crop, along with their seasonal incidence and economic importance. namely, rice butterfly (Melanitis leda ismene Godfrey), rice grass hopper Roving survey and fixed plot survey indicated that totally 13 insect species (Oxya nitidula Walker) and paddy spider mite (Oligonychus oryzae Hirst) were found attacking paddy during Kharif season and all of them have incidence was also recorded in the crop but the pests caused not much been identified (Table 1). economic loss. During the survey, brown plant hopper (Nilaparvata lugens Stal), and white backed plant hopper (Sogatella furcifera Horv.) were found to be the key pests of rice under irrigated conditions during kharif season. The paddy Biology of root mealy bug, Geococcus citrinus Kuwana stem borer Scirpophaga incertulas Walker caused moderate damage (Rhizoecini: Pseudococcidae), a new pest on banana which was comparatively low in Kharif than in Rabi.The other major pests inKerala Maicykutty P. Mathew, K.C. Soumya and M.S. Smitha Table 1: List of Pest of Paddy Banana Research Station (Kerala Agricultural University), SI. Scientific Period of Economic Kannara, P.O., Trichur, 0487- 2699087, India name infestation No status The mealy bug, Geococcus citrinus Kuwana (Pseudococcidae: 1 Orseolia oryzae September to Homoptera), was recorded as a pest attacking the roots of banana c.v. Woodmason October Low Nendran in Kerala (Smitha et al., 2007). The biology of the pest was not 2 Dicladispa armigera Olivier July Low studied fully as the rearing method was not standardized. Males were 3 Hydrellia phillipina Ferino August to September Low also not recorded. Hence to bridge the gap, a detailed study was 4 Cnaphalocrocis September to undertaken on the biology of G. citrinus at Banana Research Station, Kannara, Kerala, South India. medinalis Guenee October Low 5 Scirpophaga incertulas Walker October Low The mealy bugs were reared on sprouted green gram seeds, surface 6 Melanitis leda ismene Godfrey October Very low sterilized with cairbendazim 0.01% for 5 minutes. The study showed that G. citrinus is a bisexual species. The life cycle of females consisted of 7 Nephotettix sp. August to December Moderate three stages, namely,egg, nymph and adult while that of male 8 Nilaparvata lugens Stal October to December Severe consistedof four stages, namely, egg, nymph, pupa and adult. Adult 9 Sogatetella furcifera Horvath October to December Severe female:- apterous, white, body covered with thin wax filaments. The 10 Steneotarsonemus November to average length and breadth were 2.9 mm and 1.48 mm respectively. spinki Smiley December Moderate Adult male: - winged ,pale brown, with a pair of narrow, elongate opaque wings. Average length is 1.64 mm and width, 0.19 mm. Egg: - 11 Mythimna sp nr Albavena November to December Very low pearly white, elongate oval, translucent, covered with wax filaments 12 Oxya nitidula Walker September to November Very low produced by the female and are laid in groups or in chains. The 13 Oligonychus oryzae Hirst September to October Very low average length was 0.37 mm and average width was 0.15 mm. The 6 Insect Environment, Vol.17(1), April-June 2011 Insect Environment, Vol.17(1), April-June 2011 7 number of eggs laid was 128. 2 per female. Nymph: - white; elongate of 5.20±0.78 days. The larvae measured 24.0 to 29.0 mm in length with oval and body covered with wax filaments. There were three nymphal an average of 25.80 ± 1.80 mm and head capsule width measured from instars. The first instar nymphs measured 0.47 mm in length and 0.14 1.65 to 1.96 mm with an average of 1.79 ± 0.11 width. This instar lasted mm in breadth, second instar with 0. 52 mm in length and 0. 16 mm for 5 to 7 days with an average of 5.70 ± 0.67 days and larvae measured in breadth and third instar with 1.23 mm in length and 0. 43 mm in 37.0 to 49.0 mm in length with an average of 42.68 ± 4.21 mm and head breadth. Pupa:- smaller in size, pale white, and has an average length capsule was 2.78 to 3.30 mm with an average of 3.02 ± 0.19 mm in width, of 0.89 mm and breadth of 0.28 mm. respectively. Fifth instar occupied six to eight days with an average of 7.05 The average duration of different life stages were as follows: eggs- 10.8 ± 0.83 days and this instar measured 55.0 to 64.0 mm in length with an days, nymphs- 18days and pupa- 5.0 days. The total life cycle took average of 59.26 ± 3.51 mm and 4.60 to 5.04 mm with an average of about 29-34 days. The average life span of adult female was 15.1 days 4.89 ±0.15 mm head capsule width, respectively. Under laboratory and that of male was 5.0 days. The ratio of male: female was observed conditions A. convolvuli occupied 21 to 30 days with an average of 26.35 to be 1: 22.5. The complete biology is being reported for the first time. ± 2.47 days (Table. 2). References: Fully grown larvae stopped feeding and wriggled into the soil. The body Smitha, M. S. and Mathew, M. P. 2007, Root mealybug -Anew pest problem on size gradually shortened became rough inside the soil and entered pre- banana in Kerala. In Proc. National Conference on Banana, October 25-28, pupal stage. The pre-pupal stage occupied 2-4 days with an average of 2007, pp.18-19 2.95 ± 0.68 days. Pre-pupal length varied from 52-57 mm with an average Acknowledgement : of 54.26 ± 2.50 mm. Pupal stage lasted for 12-17 days with an average The authors acknowledge the financial support by Kerala State Council for of 14.8 ± 1.11 days. Under laboratory conditions the sphingid completed Science, Technology and Environment. one generation (egg to adult) in 41 to 59 days with an average of 51.80 ± 5.60 days. The sex ratio was 1:1.Emergence of the adult usually occurred during night. Rarely emergence occurred during day time Biology of hawk moth, Agrius convolvuli L. on blackgram but rare. Mallappa Chandaragi, R. R. Pail! and R. K. Pail! The longevity of the adult female ranged from 13-15 days with an average Department of Agricultural Entomology, College of Agriculture, of 13.8 ± 0.92 days. While in male it was 10-12 days with an average of University of Agricultural Sciences, Dharwad - 580 005, India 10.7 ± 0.83 days. Mating was observed during night hours a day after emergence, copulation lasted for 30 minutes. Fecundity ranged from 82 Among different pests of blackgram, Agrius convolvuli has gained major to 129 with an average of 104.0 ± 16.53 eggs per female. Similar studies pest status in recent years. Biology of this pest was studied on blackgram at Department of Agricultural Entomology, University of Agricultural have been reported by Chougala (1993) on black gram, while with that Sciences, Dharwad, Karnataka. Nagaraja (1993) and Jayaram (2006) on greengram, respectively. From this is clear that host does not make any difference in growth and The females laid small bright bluish eggs individually on all parts of the development of Agrius convolvuli on black gram and green gram, plant. The eggs were short ovoid, slightly concave at one end and the respectively. surface of the egg was smooth and shiny. The incubation period lasted for 6 to 9 days with an average of 7.80 ± 1.03 days (Table 1). Egg References: measured from 0.96 to 1.02 mm. Neonate larva was tiny, cylindrical with Chougala, D. C.(1994). Biology and management of hornworm, Agrius convolvuli pale green body and head. First instar lasted for 4 to 5 days with an L. on greengram, Vigna radiata (L) Wilczek.

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