The giant grey slug Limax maximus  measures 10-20 cm in length and is generally light grey or grey-brown colored with darker spots and blotches. Concerning tree slug Limax marginatus, it can grow up to 7 cm in length, body colour is pale grey and is marked by two dark lines on both sides of the body and it is found mostly climbing trees. Since few years, certain terrestrial slugs became serious gardenpests in Egypt infesting numerous agronomic, horticultural and ornamental plants. Gamil  studied, in details, ultrastructure of spermatogenesisstages of the garden slug Limax flavus as well as Cuezzo in mollusks of family Orthalicidae (Stylommatophora). On the other hand, several wild plants have been screened for their molluscicidal activity against them. The plant molluscicides must have a high potency to slugs and low toxicity to non-tested living organisms. These plants must further be the source of cheap, effective and environmentally acceptable products. In this concern, many plant extracts are products favoured as biocontrol agents against such slugs, from which the wild Za’ater plant (O. syriacum) was recommended.