The Predators, Stethorus gilvifrons (Coleoptera), Scolothrips Ion­gicorns (Thysanoptera) Onus spp. (Heteroptera), and Amblysieus spp. (Parasitiformes), were surveyed on castor trees, (Ricinus communis) throughout 1997 and 1998 seasons in Ismailia Governorate. The preda­tors were found over the two years, despite the temperature and rela­tive humidity that affected their population density. The first two preda­tors were more abundant than the other two. The four predators were found in each of the five surveyed districts (Fayed, Quantra Gharb, Ismai­lia, Quantra Shark and El-tall El-Kebeer) with no significant differences. S.glivifrons and Orius spp. showed negative correlation with temperature and R.H. in 1997, however, positive correlation with temp. was evident in 98. S.longicornis and Arntolyseius spp. showed positive and negative cor­relation with temperature and relative humidity, respectively during both seasons. Moreover, the effect of ten insecticides and acaricides varied in their action on the predators, while five fungicides; four herbicides and the nematicide Vydate did not prove to be harmful against the collected predators. It is recommended that castor bean plants can be planted in farms and as hidge or border where wind is blowing to serve as a source of predators owing to their existence throughout the whole season. The use of harmful pesticides to the predators against pest on economic crops must be avoided to preserve such predators.