SAXENA, S.P.PATEL, KETANKUMAR B.2016-04-292016-04-292012-01http://krishikosh.egranth.ac.in/handle/1/65656Investigations were carried out on seasonal cyclicity, population dynamics, reaction of different mango cultivars, estimation of avoidable losses and evaluation of non-chemical treatments against important insect-pests of mango under field conditions at RHRS (ASPEE farm), Navsari Agricultural University, Navsari, during 2009-2011. During the course of investigation, insect-pests studied were mango hopper complex, thrips complex, leaf gall midge, leaf webber and fruit fly along with their natural enemies were observed. Population of mango hopper complex was observed throughout the year with higher population from flower initiation or panicle emergence to the stone-sized fruits stage. Highest population of mango hoppers (8.46 hopper/panicle) was observed on 14th standard week (SW) coinciding with stone sized fruit stage. It was positively influenced by maximum temperature, sunshine and evaporation and negatively by evening relative humidity, wind velocity and rainfall. Similarly, thrips appeared from third week of August to second week of June and was at peak during second week of April. Peak populations of flower thrips (43.33/panicle) and foliage thrips (29.46/twig) were observed on 15th and 42nd SW coinciding with stone sized fruit and emergences of new flush stages, respectively and were positively influenced by maximum temperature, sunshine and negatively by minimum temperature, relative humidity, wind velocity and rainfall. The leaf gall midge damage was observed throughout the year, wherein peak damage of the pest (60.49 %) was observed on 7th SW coinciding with pea cum marble stage. It was also positively influenced by sunshine and negatively by temperature (minimum and average), relative humidity, rainfall and wind velocity. Leaf webber or tent caterpillar was seen infesting mainly the old foliage during October and November with highest webbing (8.13/tree) on 42nd SW. Similarly, it was positively influenced by minimum temperature, relative humidity and rainfall and negatively by maximum temperature, wind velocity, sunshine and evaporation. Highest fruit fly infestation (36.67 %) was observed on 22nd SW coinciding with ripening cum harvesting period of mango and it increased with increase in temperature, relative humidity, wind velocity and evaporation. Highest spiders (3.50/panicle) were observed from 9 to 10 SW, when, the days were bright sunny and resulting in high evaporation witnessing higher population of hopper, thrips and leaf gall midge damage and lower webbing of leaf webber. Population of Chrysoperla was highest (2.00 larvae/twig) on 40th SW and was not influenced significantly by any weather factor. Hoppers and thrips remained high during 10-17 SW (5.20 to 8.46) (25.44 to 43.33) and were low in numbers during 23-28 SW (0.61 to 0.97) (0.00 to 5.68) respectively, indicating positive synchronization between the two. Hoppers were negatively associated with damages of leaf gall midge (‘r’= -0.2654) and leaf webber (‘r’= -0.2977). Similarly, thrips were negatively associated with leaf webber (‘r’= -0.2425) and fruit fly (‘r’= -0.2495) and there could be some type of pest displacement or interspecific competition between them. Association of leaf gall midge with leaf webber was inverse (‘r’= -0.4711) indicating displacement or interspecific competition between the two. Alphonso was considered most susceptible mango cultivar followed by Kesar. Whereas, Totapuri was considered least susceptible cultivar. Application of recommended as well as need based insecticides in protected plots resulted in significantly lower hoppers (3.95 hoppers/twig or panicle) and thrips (5.47 thrips/twig or panicle) and damages of leaf gall midge (7.24 % leaf damage), leaf webber (3.54 web/tree) and fruit fly (7.86 % fruit infestation) as compared to the unprotected plots. Number of fruits set at stone (378.54/tree) and harvest stages (232.25/tree) were higher in protected trees giving significantly higher yield in protected (58.06 kg/tree) over untreated (21.82 kg/tree) trees followed by significant lower fruit dropping (38.51 %) in the former over the latter (50.58 %). The avoidable yield losses due to insect-pests was to the tune of 61.51 per cent resulting into net profit of Rs. 69,780/ ha. in protected trees over control. Package of Non Pesticide Management (NPM) proved most effective indicating lowest hoppers (3.40), thrips (5.04) and leaf gall midge damage (11.02 ), leaf webber (2.41) and fruit fly (6.76 ) and it also led to the highest fruit setting at marble cum stone (1158) and harvest (922.50) stages. Highest fruit yield (230.63 kg/tree) in NPM treated trees provided highest Net Incremental benefit cost ratio (NICBR) of 1:31.60 per ha.enmangoes, fruits, developmental stages, harvesting, budding, peas, relative humidity, biological phenomena, biological interaction, cropsThesis