Abstract
The aim of this study was to determine the effect of intercropped crops under date palm trees on the infestation level by P. blanchardii (Hemiptera: Diaspididae) infesting seedy Balady date palm leaflets at Esna district, Luxor Governorate during the two years of (2010/2011 and 2011/2012). The obtained results showed that P. blanchardii occurred on all the tested date palm trees all the year round. As well as, the half monthly observations of this insect had four peaks of seasonal activity per year were recorded in all tested date palm trees (only and intercropped). Also, the highest population density of P. blanchardii with mean number of 8.51 and 7.08 individuals per leaflet was recorded when Alfalfa plants were intercropped under date palm trees. Followed by sugarcane plants were intercropped under date palm trees when observed the mean number reached (8.00 and 6.76 individuals per leaflet) during the two years, respectively.
In contrast, the least infestation as average 5.54 and 5.57 individuals per leaflet was observed when banana trees cultivated under date palm trees for two years, respectively. While, the moderate infestation with mean number of 7.29 and 6.36 individuals per leaflet was recorded when date palm trees were single during the first and second years of study, respectively. The results showed that the climatic conditions of autumn and summer months during the first year and winter, spring and summer months during the second year were the optimal for the insect multiplication and build up were recorded on tested date palm trees, since the highest R.M.V.P value was achieved during two years.
The analysis of variance indicated highly significant differences between the population means among the different intercropped crops under date palm trees through the two years. On the other hand, there were insignificant differences among Alfalfa and sugarcane plants were intercropped under date palm trees regarding the level of infestation.
Finally, this work may add some information to be used in integrated pest management programs for controlling white date palm scale insect, P. blanchardii.