Population dynamics and insecticidal management of the mango thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) in South Gujarat.
Kumar S., Patel C. B., Bhatt R. I., Rai A. B.
Author Affiliation: Agriculture Experimental Station, Gujarat Agricultural University, Paria, District Valsad, Gujarat, 396 145, India.
Pest Management and Economic Zoology 2 : 59-62
Abstract : Field experiments were conducted during 1990-93 at Paria, Gujarat, India, to study the population dynamics and control of Scirtothrips dorsalis on mango cv. Alphonso. Higher incidence of S. dorsalis was observed during March-April and September-October coinciding with the new flush. The leaf infestation was highest (30.5-31.5%) during October and remained at a low level during the remaining months. The impact of temperature, relative humidity, rainfall, rainy days and sunshine hours on infestation was non-significant. Application of monocrotophos (0.05%) was most effective (1.61 nymphs/panicle, 11.26% leaf infestation) and was on a par with carbaryl (0.1%) which in turn was on a par with cypermethrin (0.003%), deltamethrin (0.0075%), fenvalerate (0.01%), quinalphos (0.05%) and endosulfan (0.05%). Monocrotophos (0.05%) recorded the greatest fruit bearing (467.75 fruits/tree) and yield (117.04 kg/tree) and differed significantly from other treatments. Maximum additional income over control was achieved with monocrotophos (Rs 600.97/tree) followed by carbaryl, quinalphos, endosulfan and synthetic pyrethroids. Cypermethrin gave the greatest cost benefit ratio (1:209) followed by deltamethrin (1:89), fenvalerate (1:73), endosulfan (1:66), monocrotophos (1:62), carbaryl (1:39), quinalphos (1:33), dimethoate (1:32), methyl demeton (1:11) and Neemark (1:10).