Studies on the control of Dubas bug, Ommatissus lybicus DeBergevin (Homoptera: Tropiduchidae), a major pest of Date Palm in the Sultanate of Oman

• Main Author: Al Sarai Al Alawi, Mamoon
• Other Authors: Wright, Denis
• Published: Imperial College London 2015
• Subjects: 634
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.694010

Date Palm (Phoenix dactylifera L. Family: Arecaceae; sub-family: Poaceae) is thought to be the oldest fruit tree grown in the Sultanate of Oman and is a major crop in terms of the number of trees and their distribution. Dates are widely considered to be a strategic source of food security as well as an important cash crop, and have always been looked upon as a key source of stability for oasis agro-ecosystems. Several insect and mite pests and plant pathogens attack Date Palm trees. The Dubas bug, Ommatissus lybicus DeBergevin (Homoptera: Tropiduchidae), has been considered the key pest of Date Palm plantations in Oman for 40 years due to the total area infested, the severity of infestations and the scale of the crop losses. Current control programmes for Dubas bug are reliant on chemical pesticides, applied by air and from the ground over an area ranging from 12,000-20,000 ha annually. These pesticides are currently the only feasible control measure against this pest, although research is underway on bio-control technologies. The cropping environment resulting from traditional Date Palm cultivation - high planting density, high temperature and humidity, topography of the plantations, intercropping and variability in cultivars and plant height - has an influence on pest and disease incidence and also affects the control options available. The present research attempts to determine the effects of technical, environmental and biological factors on the control of Dubas Bug in order to develop a more integrated control strategy. Data have emerged from this study on: 1) optimal spray droplet spectrum and application rates for improved coverage and placement of spray deposits, including under leaf deposition; 2) information on how Dubas bug daily movement can influence control efficacy; 3) on the selective use of insecticides against Dubas bug at economic threshold levels as a supplement to other IPM methods, including cultural practices such as thinning to maintain optimal distances between trees, irrigation management, the removal of old leaves including pruning cuts and surrounding tissues that may support and harbour Dubas bug.