The infectivity of three Egyptian Heterorhabditid nematode species Heterorhabditis bacteriophora (Poinar), Heterorhabditis indica (Poinar)and Heterorhabditis baujardi (Poinar) ( Rhabditida : Heterorhabdilidae) and one imported Steinernematid species, Steinernema abbasi (Elawad) (Rhabditida: Steinernematidea) were evaluated against preadult of  the citrus mealybug Planococcus citri (Risso) (Hemiptera: Pseudococcidae)and adult of Egyptian mealybug Icerya aegyptiaca (Douglas) (Hemiptera: Monophlebidae)under laboratory conditions. Also, laboratory and semifield evaluation of the efficiency of entomopathogenic nematodes (EPN) alone or mixed with wax remover Oleyl-polypeptide, against adults and nymphs ofthe mealybug Ferrisia virgata  (Cockerell)  (Hemiptera: Pseudococcidae)were carried out. Nematode reproduction in their cadavers were detected. Moreover, the effect of Steinernema carpocapsae alone or with medical additive (Docusate Sodium) comparing with Super Misrona oil were studied on the grape mealybug, Planococcus ficus (Signoret). Three methods of formulation of Egyptian entomopathogenic nematodes were tested for their effectiveness on H. bacteriophora and S. carpocapsae. These formulations are water-dispersible granules (WDG), Calcium alginate geland infected cadavers. The infectivity of the formulated nematodes was tested against I.  aegyptiaca adults.