Persistence of neem-based products against sweetpotato whiteXy Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) was tested in air conditioned rearing rooms and tropical netted greenhouses (GHs). Two commercial neem products, NeemAzal ® -T/S (1% azadirachtin) and NeemAzal ® -U (17% azadirachtin), were used. Foliar application, under room conditions at dose-rates of 7 and 10 ml NeemAzal ® -T/S, induced an immature mortality of 32 and 44%, respectively, whereas 7 days post-application, under GH conditions, mortality rates declined to 5 and 7%, respectively. This result indicated rapid dissipation of the active ingredients. However, systemic application by soil drenching resulted in more stable eVects under both laboratory and GH conditions. After soil drenching with solutions of 3.0 g NeemAzal ® -U until 7-day, immature mortality declined from 88% for the Wrst day to almost half (45%) by day-7 in the GH, and from 90% on Wrst day to 64% by day-7 under laboratory condition. Similar response trends for B. tabaci were obtained for other parameters such as adult colonisation, egg deposition, and egg hatch. The loss of eYciency of the neem products was clearly related to dose-rate, methods of application, and environment (temperature and UV). Soil application is therefore, a convenient approach to achieve high eYciency and persistence with neem products under the conditions in tropical GH environments for whiteXy management.