RUGOSE SPIRALING WHITEFLY INFESTATION ON COCONUT: THREATS AND REMEDY

Abstract

Rugose spiraling whitefly (RSW) Aleurodicus rugioperculagus (Hemiptera: Aleurodidae) is an invasive pest causing severe damage to coconut plant, having higher percent of infestation (70.2% to 165.4%). The nymph and adults suck cell sap from the underside of the leaves and secret honeydew that develop sooty mold fungi and interfere the growth of the plants. It was first identified in Bangladesh in 2019 on coconut plants in Jashore.Then it has spread to almost all other districts in Bangladesh. Highest coconut tree infestation was observed in southwestern part (97.5%) and lowest (68.0%) was in central part of the country and there was no significant difference among locations. In the coastal regions, the highest percent (97.0%) of infested coconut tree, infested fronds (96.2%) and leaflet area (84.0%) was recorded in Bagerhat district while the lowest percent infested tree (68.0%), fronds per tree (67.2%) and leaflet area (48.0%) was in Cox’s Bazar. The abundance of RSW increases as the number of leaves increased. Higher percent tree infestation (85.7%) was noticed in native while it was lower(81.2%) in dwarf coconut plants although no significant difference was observed.Low abundances of adult RSW were also found in dwarf coconut plants than that of native ones. The highest incidence of whitefly of coconut was observed in summer months of April-May andthe lowest was in June-July. Biological control is an effective measure where Encarsia guadeloupae, lady bird beetleand lacewings are common predators and entomopathogenic fungi Isaria fumosorosea reduces the incidenceof RSW from 77.8 to 75.1%. Various cultural and mechanical practices also significantly reduce the pest incidence, infestation, abundance of egg, nymph and adult by 50.0%, 49.9%, 49.7%, 50.1% and 49.8% respectively. Different systemic neonicotinoid insecticides also showed successful result in controlling rugose spiraling whitefly