Application of Serology to Evaluate the Relationship between Some Sugar
Beet Insect Pests and Their Predators

• Asmhan E. Youssef*, H.A. Boraei*, E.M. El-Kady** And A.A. Farag***
• * Econ. Entomol. Dept. Fac. of Agric. Kafr El-Sheikh Tanta Univ., Egypt.
• ** Agric. Botany, Dept. Fac. of Agric. Kafr El-Sheikh Tanta Univ., Egypt,
• *** Plant Protection Res. Institute., Sakha, ARC.
• The Third International Conference onIPM Role in Integrated Crop management and Impacts on Environment and Agricultural Products.

Abstract

Prey predator relationships had been studied by three methods; using serology by double diffusion test, analyzing statistically the correlation between population fluctuations of both groups in sugar beet fields and evaluating the feeding efficiency of the predators in the laboratory. This work was conducted from 2001-2003 at the experimental farm and Economic Entomology Department, Kafr El-Sheikh Faculty of Agriculture. Serological studies by doubled diffusion test revealed sharp reactions (positive) between antigens of aphids the tortoise beetle, the beet fly, the stink bug, the beet moth, and Chrysoperla carnea (Steph.) antiserum, the precipitin lines were 5, 6, 4, 2 and 2 lines, respectively. Sharp reactions were found also between the antiserum of the ladybird and all of the aphids, the tortoise beetle, the beet fly the stink bug and the beet moth antigens, the precipitin lines were 6, 4, 5, 0 and 3 lines, respectively. The two antisera of the two tested predators when tested with the antigens of the other predators, no reactions were detected. The lacewing, Ch. carnea appeared from Nov. to Apr. larvae had one peak (41 and 25 individuals. in the first and second seasons, respectively, during Apr. That peak followed by peaks of Cassida vittata Vill., Pegomyia mixta Vill., Scrobipalpa ocellatella Boyd., Aphis spp. and Nezara viridula L. in the same month. Coccinella undecimpunctata L. had two peaks of abundance. In the first season, the first peak was recorded in Nov. (45 individual), associated with the aphid. The second peak (30 individi.) was found at the same time of the peaks of C. vittata, P. mixta, S. ocellatella, Aphis spp. and N. viridula, in Apr. In the second season those peaks were found in Nov. and Mar. (48 and 24 individuals.), respectively.

When Ch. carnea was reared on the tortoise beet beetle, the beet fly and the beet moth it consumed 175.35 beet beetle eggs, 79.75 of the tortoise beet beetle larvae, 179.75 beet fly larvae and 67.5 beet moth larvae during 9.75, 10.05, 9.50 and 10.25 days, respectively. C. undecimpunctata consumed 428.51 beet beetle eggs, 168.25 beet beetle larvae, 270.25 beet fly larvae, , 127.25 beet moth larvae during 9.25, 9.75, 11.80, 13.75 days, respectively. Those results suggest that serological techniques might be used in detecting the relationship between the predators and the insect pests, the precise and quick method which now widely used in insect researches and rarely used in Egypt.