A survey was conducted on seven deciduous fruit trees (apple, apricot, fig, grapevine, peach, pear and plum) to detect the borers at‌tacking these trees. Collected borers were 37 species which belong to seven families of two orders: Coleoptera (34 species) and lepidoptera (3 species). Seasonal activity of Agrilus lituratus beetle occurred during the period from 4th week of May until 3 rd week of August with one peak in the 1st week of July, while the activity period of Ptosima undecim - ma‌culata extended from 1st week of March until last week of September recorded three peaks of population. However, two peaks of Sphenoptera tapped beetle showed during its activity period extended from 4 th week of April until 3 rd week of September. Relative susceptibility of different hosts by some borers indicated that high differences were detected between the percentages of infes‌tation of each borer on different hosts. Seasonal abundance and transformation of developmental stages of Niphona picticornis borer on fig trees exhibited that this insect has one generation yearly. larval duration average was 205 ± 75.67 days, while the prepupal and pupal durations recorded 9.4 ± 4.05 and 18 ± 4.78 days, respectively. The highest popuftion percentages of prepupa and pupa recorded in September. The adults stay inside the branches between 63 to 168 days, while their longevity from 7-80 days. The highest population percentage of beetles inside host recorded in Decem‌ber, while the highest percentage of emerged beetles detected in Janu‌ary and March. Sphenoptera trispinosa beetle has two peaks of population, while its parasite, Cratocentrus sp., has three peaks during the activity period extended from April to setpember. Monthly percentages of parasitism differ during successive months of activity, general percentages of para‌sitism were 29.4% and 29.6% in 1996 and 1997, respectively. Highest percentage of emerged parasites recorded from eastern direction•and at 50-100 cm. height.