FUNCTIONAL-RESPONSE OF ENCARSIA-FORMOSA (GAHAN) PARASITIZING CASTOR WHITEFLY, TRIALEURODES RICINI MISRA (HOM, ALEYRODIDAE)

Laboratory experiments were conducted to measure the functional respon se of Encarsia formosa parasitizing castor whitefly, Trialeurodes rici ni. Parasitoids were isolated singly for 24 h in 10 cm Petri dishes wi th either 4, 8, 16, 32, 64 or 128 prepupal stages of T. ricini. Result s showed a typical Type II response, with up to 12 prey attacked when 128 were provided. The rate of attack and handling time were 1.43 and 0.077 (days), respectively. Theoretically, one T. ricini prepupa could be parasitized by E. formosa every 111-115 minutes (0.077-0.080 days) , and an adult E. formosa could parasitize a maximum of 13 castor whit efly prepupae per day.