Abstract
In this study, honeybees have been exposed to tau-fluvalinate to assess survival and determine the concentration at which the highest mortality occurred, and the extent to which this pesticide affects the internal organs of the digestive system. Four different concentrations of tau-fluvalinate were used (3.6, 6.25, 12.5, 25.5 mg/L) on the forager honeybee worker. The adult workers were under continuous observation and assessed after 12, 24, 48, 72, and 96 h following the treatment by LC(50)( )of tau-fluvalinate to determine adult workers' longevity. According to the results of this study, a 13.700 mg/L concentration of tau-fluvalinate kills half of the individuals. Also, there is a direct relationship between the time of exposure to the pesticide and its effect on the survival of adult workers. Also, the midgut was found to be torn and incoherent and showed signs of shrinking. The colour of the ileum became transparent also after the treatment, its walls shrunk, and thin lines appeared. Also, it was found that the rectum, after the treatment had very thin walls that were almost lacerated. This provides a useful indicator of the possible effect of tau-fluvalinate, which was found to have negative effects on worker body parameters and bee anatomy.