LAUSR

This study was conducted in the apiary of Faculty of Agriculture, Cairo University, Egypt, to examine and determine the effect of Imidacloprid & Chlorpyrifos and their nano compounds on certain morphological characteristics of honeybee workers. This study proved that: Chlorpyrifos and nano-chlorpyrifos compounds showed more toxicity and harmful than Imidacloprid and nano-imidacloprid towards honeybee workers, especially on body balling extent and mouthparts out & straight by percentages 80.27% and 78.71% for nano-chlorpyrifos and chlorpyrifos, respectively. Imidacloprid and its nano form had the same effect approximately for body balling, legs shrinkage and abdomen length. In contrast, nano-imidacloprid recorded the lowest damage on honeybee wings horizontality and mouthparts out & straight by percentages 46.40% and 16.92%, respectively. Also, only nano-chlorpyrifos showed negative and significantly effect on abdomen length of honeybee worker by value 0.48 cm.