Browsing by Author "KOTESWARA RAO, POLURU"
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ThesisItem Open Access SEASONAL ABUNDANCE AND MANAGEMENT OF MAJOR CITRUS PESTS OF SOUTH ZONE(ACHARYA N. G. RANGA AGRICULTURAL UNIVERSITY, RAJENDRANAGAR, HYDERABAD, 2004) KOTESWARA RAO, POLURU; SAVITHRI, PStudies on seasonal abundance of major pests of citrus were under taken on Sathgudi sweet orange and Balaji acid lime during June 2003 to May 2004. On sweet orange incidence of leaf miner Phyllocnistis citrella Stainton was peak during January and was negligible during April to July whereas on acid lime, peak incidence was noticed during December and negligible from April to June. Larval population of citrus butterfly Papilio demoleus Linnaeus was high during December and November and there was negligible during summer period (April and May) on both hosts viz., sweet orange and acid lime respectively. The incidence of citrus psylla Diaphorina citri Kuwayama was moderate during November and December on sweet orange and acid lime respectively, and incidence was recorded little during the months of July to October and February to April on both hosts. In case of weevil Myllocerus sp. population, peak occurrence recorded during October. No incidence of weevil was recorded during April and May on sweet orange and during May and June on acid lime. High incidence of leaf folder Psorosticha zizyphi St. was recorded during February on sweet orange whereas on acid lime it was high during February and December. There was no activity of black fly Aleurocanthus woglumi Ashby. throughout the year. In case of green mite Schizotetranychus hindustanicus Hirst. the incidence was more during November on sweet orange while on acid lime peak population was noticed during March. Rust mite Phyllocoptruta oleivora Ash. attained peak during March and January on sweet orange and acid lime respectively. During the study of seasonal occurrence of various pests some of the insects like psychids, Clania crameri, W. chaliella vitrea, Pteroma sp., loopers, Gonodontis clelia, Somatina purpurescens, and semi looper Paralellia palunba L. were also recorded as pests of citrus, which is first record in this region. During the period of study a larval parasitoid, Tetrastichus sp. on the larvae of leaf miner, P. citrella, two braconid parasitoids viz., Apanteles papilionis Viereck, Bracon hebetor S. and one predator Rhynocoris marginatus Fab. were found to be associated with a larval population of citrus butterfly, P. demoleus. Four coccinellid predators viz., Coccinella septumpunctata L., Chilonemus sexmaculata F., and Brumus suturalis F. and Chilochorus nigritus F., one lace wing Chrysopa sp. and an unidentified preying mantid as well as a parasite Tetrastichus sp. were found associated with nymphs of psylla, D. citri. A pentatomid bug, Amyotea malabarica Fab. was identified as predator of adult weevil, Myllocerus discolor Boh. Natural and synthetic insecticides were evaluated against citrus leaf miner, P. citrella under field conditions both as prophylactic and curative control measures. In the prophylactic control of leaf miner with natural products, all the treatments viz., NSKE, azadirachtin, neem soap, pongamia oil, pongamia soap, garlic extract, Bacillus thuringinesis (0.005% and 0.0025%) offered total initial protection keeping the citrus plants free from leaf miner attack upto three days. However NSKE, azadirachtin and Bt. (0.005%) effectively checked the incidence even upto five days. In curative method of leaf miner control Bt at both concentrations (0.005 and 0.0025%) found highly effective upto 10 days recording 100 per cent reduction. This was followed by azadirachtin and NSKE. Among synthetic insecticides, profenophos, lambda cyhalothrin and fenvalerate were the most effective as prophylactic treatments which checked the leaf miner incidence upto seven days. Cartap hydrochloride was comparatively less effective as it lost its efficacy in three days after spraying. As curative method of evaluation by synthetic insecticides, thiodicarb, lambda cyhalothrin and fenvalerate offered effective control by offering cent per cent mortality by third day. Cartap hydrochloride and chlorpyriphos were comparatively less effective treatments. Against larval population of citrus butterfly, P. demoleus both concentrations of Bt. (0.005 and 0.0025%) were to be as the most effective treatments showing cent per cent mortality at five days after spraying. All the synthetic insecticides offered cent per cent larval mortality at five days after spraying.