Spinosyns are new neurotoxins mixtures produced during fermentation of a soil actinomycete that have high activity
towards different pests. Spinosyns compounds were represented in Spinosad and its evoluted compound ,Spinetoram
,which were tested for their toxic effects under laboratory conditions against adult females of Aphis gossypii Glover
and Tetranychus urticae Koch ,and the fourth instar larvae of Spodoptera littoralis (Boisd.)by leaf-dip technique.
Spinosad LC50's of A. gossypii , T. urticae and S. littoralis were 30.417,25.982 and 5.379 ppm, respectively but they
were 0.596,0.370 and 1.742 ppm,respectively in case of Spinetoram.The superior Spinosyn compounds,Spinetoram
gained the best results against piercing-sucking pests compared with Spinosad which was the best against S. littoralis
,so the present histological studies were concerned with Spinetoram.Each pest was treated with its LC50 value.
Histological defects after treatments in the neuromuscular nicotinic receptors were detected and discussed.