Seasonal occurrence of and injury caused by thrips and their control on mangoes.
Lee H. S., Wen H. C.
Author Affiliation: Department of Plant Protection, Fengshan Tropical Horticultural Experiment Station, Taiwan Agricultural Research Institute, Kaohsiung 830, Taiwan.
Plant Protection Bulletin, Taiwan 24 : 179-187
Abstract : Studies were carried out in Taiwan on the seasonal occurrence, injuriousness and control of Rhipiphorothrips cruentatus Hood, Scirtothrips dorsalis Hood and Thrips hawaiiensis (Morg.) on mango. In general, injury was caused by puncturing and sucking sap from the epidermis of leaves and fruits. Affected areas turned dark or developed scars; leaves became blackened on their growing points, curled and finally dropped. In extreme cases, there was almost complete defoliation. Feeding punctures served as sources of entry for fungal attack. S. dorsalis was abundant throughout the year at both Fengshan and Yuching, whereas R. cruentatus was abundant only at Fengshan. T. hawaiiensis occurred only at the blooming stage. The population density of R. cruentatus and S. dorsalis was inversely related to the amount of precipitation. The percentage of damaged fruit, which was closely related to populations of S. dorsalis, was 36 at Fengshan and 40 at Yuching. Applying insecticides and fungicides prior to full blooming and then wrapping paraffin paper bags on the whole fruit cluster before fruits were 1 cm in diameter prevented damage.