Green pea Pisum sativum,leguminasae is one of the most popular vegetable crops in Egypt. It is liable to be attacked by several destructive pests that cause great yield damage, which can result in greater than 50 %yield reduction. Many insect pests belonging to the different orders, such as Liriomyza trifolii (Burgess), white fly Bemisia tabaci Genn and red spider Tetranychus urticae. The goal of the present work is to determine the population activities of certain pests infesting Green pea as well as the numbers and duration of seasonal field generations. The combined effects of some climatic factors on the tested insect pests also were studied. Experiments were conducted at Manawat district, Giza Governorate on the autumn's of 2014 and 2015 seasons. The relationship between the minimum, maximum temperatures and relative humidity average as well as the age of plants against the population of the target pests infesting on the leaves of green peas were studied in 2014 and 2015