Suppression of white mango scale, Aulacaspis tubercularis (Hemiptera: Diaspididae) on mango trees in El-Beheira Governorate, Egypt.

Abstract

White mango scale, Aulacaspis tubercularis Newstead (Hemiptera: Diaspididae) is a serious pest on mango (Mangifera spp.), (Sapindales: Anacardiaceae) which became recently a troublesome pest in all mango orchards in Egypt. It causes fatal damage especially to late cultivars by sucking leaves which turn pale-green or yellow and ultimately die or fruit causing conspicuous pink blemishes around insect feeding sites resulting in external lesions rendering it unmarketable for export. Seasonal abundance was ‎estimated ‎throughout 2 successive years (2008 and 2009) and showed that the white mango scale (A. ‎tubercularis) had four peaks for its population density during the two studied ‎years, (April, ‎August, October and December, 2008) and (March, July, September ‎and ‎December, 2009). ‎Study of weather factors, [daily mean temperature (oC), relative ‎humidity (%), dew ‎point (oC) and wind speed (Km/h)] effects on A.tubercularis population ‎density illustrated that there was significant positive relationship between ‎‎(daily mean temperature and relative humidity) and counted population ‎density, but there was a significant ‎negative ‎relationship between ‎(wind speed ‎and dew point) and counted population ‎density. Two successive field experiments for eight weeks during early spring (2009 – 2010) aimed to test some summer/light mineral oils, (super masrona®, CAPL2® and Diver®) against A. tubercularis on ‎mango trees. The tested mineral oils were effective by the following descending order : Diver > CAPL2® > super masrona® without significant differences between diver and CAPL2 and significant differences with super masrona, with the same effective trend and same statistical means, during the two seasonal experiments. The study recorded a little numbers of natural enemies (Parasitoids (Aphytis mytilaspidis (Le Baron)andEncarsia citrina (Craw) (Hymenoptera: Aphelinidae)), and ‎predators (Chilocorus bipustulatus (L.) andScymnus syriacus Marseul (Coleoptera: Coccinellidae)). ‎It may be killed by previous bad history of chemical insecticides usage in this area.