روي دو ميزبان گياهي در دو دماي متفاوت APHIS CRACCIVORAKOCH نسبت به تراكم هاي مختلف شته سياه يونجه LYSIPHLEBUS FABARUM MARSHALL واكنش تابعي زنبور پارازيتوييد

Functional Response of Lysiphlebus fabarum Marshall to Different Densities of Alfalfa Black Aphid, Aphis craccivora Koch (Hom.: Aphididae) on Two Host Plants at Two Different Temperatures

The functional response of Lysiphlebus fabarum Marshall to different densities of alfalfa black aphid. Aphis craccivora Koch (Hom.: Aphididae) on two host plants, alfalfa(Medicago sativa L.) and locust tree (Robinia pseudacacia L.) were studied in a growth chamber conditions (55±5 R.H.. L:D 14:10 H.) and at temperatures of 20 and 27"C in 2002 in Kerman, Iran. The objectives of the present study were to find the relationship between host densities and number of hosts parasitized by parasitoid and the effect of temperature and host plant on this relation. Functional responses of Lysiphlebusfabarum in both temperatures and host plants, to different aphid densities was fitted to the Hollingʹs type II model. Searching efficiency (aʹ) and handling time (Th ) on alfalfa and locust tree were 0.0173, 2.6642 and 0.0104, 1.6005, respectively at 20"C. They were 0.0109, 3.6187 and 0.0098, 3.1269, respectively at 27 C.