Laboratory experiments were carried out in the Insectary of Economic Entomology Department, Faculty, of Agriculture, Mansoura University, from the beginning of February 2012 tell the end of March 2013 under three constant temperature degrees (20±1, 25±1 and 30±1C^o) to study the influence of three constant temperature degrees on certain biological characteristics of the coccinellid predator Nephus includens (Kirsch) when reared on the third nymphal instars of Planococcus citri Risso, Icerya seychellarum (Westwood) and Maconellicoccus hirsutus (Green) The data cleared that with increasing the temperature degrees the duration periods of the immature stages decreased, with significant differences. The obtained results revealed that the average of total consumption per larva was the highest at 25±1^oC and when this predator fed on the mealybug species P. citri during its larval stage. The results revealed that, the longevity of the predator adult stage decrease with increasing the temperature degrees, also it can be noticed that, the highest consumption rate per female at 30±1^oC comparing with the other temperature degrees. The number of deposited eggs per female was the highest 185.74± 1.92 eggs when this predator female reared on P. citri at 25±1^oC. As a conclusion the best mealybug species for the mass rearing this predator on P. citri at 25±1^oC comparing with the other tested mealybug species and the other temperature degrees.