Citrus fruit pests and management practices in Tapli Rural Municipality, Udayapur District, Nepal

Abstract

The study was conducted in Tapli Rural Municipality, Udayapur, Nepal from 31 st

August to 31 st October, 2022. Altogether 21 mandarin and 10 lime orchards were selected for the field data collection of citrus pests. The orchards belonged to 24 farmers. Direct observation, hand picking, sweeping, knockdown method, suction trap and commercial pheromone trap (Pheromate F) were used to collect insect pests. Questionnaire interview and focal group discussion was done to obtain details on insect pests damage and their management practices. Altogether 13 insect pest species belonging to 3 orders and 8 families were reported from the study sites. The pests include Bactrocera dorsalis, B. sculetaris, B. correcta, Toxoptera citricidus, T. aurantii, Pseudococcus longispinus, Coccus viridus, Ceroplastes sp., Diaphoria citri, Halyomorpha halys, Rhynchocoris poseidon, Phyllocnistis citrella and Papilio demoleus. Hemiptera (62%) was found to be the most abundant followed by Diptera (23%) and Lepidoptera (15%). The diversity of citrus insect pests of mandarin and lime orchard was 2.125 and 1.897 respectively. Bactrocera dorsalis (21.55%) was most abundant in mandarin orchard while Toxoptera citricidus (27.7%) was most abundant in lime orchard. Ten of the 13 species were categorized into major pests which were Bactrocera dorsalis, B. sculetaris, B. correcta Toxoptera citricidus, T. aurantii, Halyomorpha halys, Rhynchocoris poseidon, Diaphoria citri, Phyllocnistis citrella and Papilio demoleus. Insect pests mainly targeted fruits, foliages, leaves and shoot. Chemical pesticides used by farmers include ATSO mineral oil/Servo Agrospray mineral oil, Monocil (Monocrotophus), Rogar/ Thiodin and pheromone traps. Cultural methods included ploughing, racking, hoeing, pruning and blocking the holes in stems created by borers with mud. Mechanical methods include hand picking and pit digging.