Seasonal Abundance of Thrips hawaiiensis (Morgan) and Scirtothrips dorsalis (Hood) (Thysanoptera: Thripidae) in Mango Orchards in Malaysia

Investigation on seasonal abundance of mango flower thrips was carried out during a flowering season of December 2008 - March 2009 in a commercially managed mango orchard and a control orchard, where no pesticide was applied to control mango pests. Thrips hawaiiensis (Morgan) and Scirtothrips dorsalis (Hood) were the most prevalent species in the commercial and the control orchards, respectively. The highest number of adults was significantly found in flowers on the upper canopy, while more immatures were collected from the lower canopy in both orchards. Three major population peaks were discernible for the two species of thrips in this season. The population of T. hawaiiensis first peaked two weeks after the onset of flowering in both orchards. Meanwhile, the population of S. dorsalis peaked one week earlier in the commercial orchard, but the growth was slower in the control orchard, with the first peak occurring three weeks after the start of the flowering season. Abiotic factors, such as temperature and relative humidity, were found to have significantly influenced the abundance of thrips in this season. The effect of pesticides on the thrips population was also noticeable, with lower abundance recorded in the commercial orchard compared to the control orchard. The findings of this particular research can contribute in improving the management strategies of thrips in mango orchards