اﻻﺳﺘﺠﺎﺑﺔ اﻟﻮظﯿﻔﯿﺔ ﻟﯿﺮﻗﺎت اﻟﻤﻔﺘﺮس Chrysoperla carnea (Stephens ﺗﺠﺎه اطﻮار ﻣﺨﺘﻠﻔﺔ ﻣن ﺣﻮرﯾﺎت دوﺑﺎس اﻟﻨﺨﯿﻞ Ommatissus lybicus De Berg.

The functional response of second and third larval instars of Chrysoperla carnea (Stephens), against different nymphal instars of Dubas bug Ommatissus lybicusDe Berg. was studied.Thelarval instars of the predator exhibited Type II functional responses against the prey. Based on disk equation the attack rate(a) of the second larval instars of the predator were estimated to 1.03±0.043 , 0.94±0.015 , 0.88±0.009 and 0.77 ±0.02 and the handling time (Th) were 0.0031, 0.0039, 0.0083, and 0.008 day for second, third, fourth and fifth nymphal instarsrespectively. The third instarslarvae of the predator, the attack rateagainst these nymphal instars were 1.11±0.01, 1.04 ±0.29 , 0.97±0.017 and 0.89 with handling time 0.0019, 0.0028, 0.0064, and 0.0067 day respectively. The theoretical maximum predation(T/Th)ofthe second larval instars were322, 256,120 and114 nymphs for second, third,fourth and fifth nymphal instar respectively; while they were526, 357, 156, and 149 for the third larval instar. According to this study this predator have a good predation potential in preying on nymph of Dubas bugespecially the small nymphs (second and third ).