The effect of Metarhizium acridum and four bioactive compounds (Neem, L-Glutamic acid, Schinus molle and abamectin) in sole treatments and in combination with M. acridum was studied on the mortality of 5 th nymphal instar of desert locust Schistocerca gregaria as well as the time mortality responses and the ultra-structure of females ovary. The obtained results showed that mortality in case of Metarhizium acridum treatment reached to 100% after 14 days, while in case of neem treatment the mortality reached to 60 % after 12 days, at the same time the mortality reached up to 20 % after 10 days post treatment with L-Glutamic acid, but such mortality reached to 50 % after 14 days post treatment with Schinus molle extract, finally the mortality reached to 60 % after 11 days of abamectin treatment. All the mixtures with M. acridum caused 100 % mortality by the 5 th day post treatment. However the sole treatments caused long time to kill 50 % of treated insects (LT50), where the LT50 of M. acridum was 7.261 day as the fastest treatment, while all mixtures caused accelerate in the mortality,but the best result was obtained in case of M. acridum + neem treatment which LT50 was only1.625 day.Any way there were different effects on ultra-structure of the ovary as result of treatments used. Such effects varied between changes in nucleus shape to changes and destruction of nuclus it self.