Utilization of Some Biological Control Agents For Controlling Certain Sugar Beet Insect Pests At Kafr El-Sheikh Region In Egypt

• Ibrahim I. Mesbah, Shawky M. Metwally, Fayez A. Abo Attia, Ahmed M. Bassyouni and Gamal A. Shalaby
• Faculty of Agric., Tanta University, Kafr El-Sheikh, Egypt.

Abstract

This study was carried out during 1999/2000 and 2000/2001 sugar beet seasons at Kafr El-Sheikh region to evaluate the effectiveness of the egg-parasitoid, Trichogramma evanescens West. and the two microbial insecticides Dipel 2x and Biofly in reducing some sugar beet insect populations. Data indicated that the egg-parasitoid released on 5^th March reduced Scrobipalpa ocellatella Bayd infestation by 13.96 and 31.98% at rates of 30,000 and 60,000 parasitoids /fed., respectively. The corresponding reductions in the larval populations were 43.77 & 69.52%. When the parasitoid was released on 5^th April, the reductions in infestation were 23.56 & 45.44%, and those in larval populations were 35.27 & 58.29% for the rates of 30,000 and 60,000 parasitoids/fed., respectively. Data also showed that the parasitoid was more capable of reducing Ostrinia nubilalis Hb. when released on 5th April than when released on 5th March. The early release reduced the borer infestation by 31.28% at a rate of 30,000 parasitoids, and by 61.50% at a rate of 60,000 parasitoids. These levels increased to 32.48 and 69.01% at both rates, respectively. The reduction in larval population took the same trend, 30.43 and 52.01% when the parasitoid was released on 5th March, and 31.91 and 72.34 % when the parasitoid was released on 5th April for both rates, respectively. As for the application of biocides, Dipel 2X (Bacillus thuringiensis) and Biofly (Beauveria basssiana); in the first season (1998/1999), Dipel 2X eliminated 27.78% of Cassida vittata Vil population, 28.66% of S. ocellatella and 15.82% of Pegomyia mixta. In the second season (1999/2000), the corresponding values were 19.01, 27.10 and 38.41% insect reductions. As for Biofly, the preparation removed 6.53 & 35.53% of P. mixta population, and 24.42 & 29.65% of C. vittata l and 39.42 & 26.43% of S. ocellatella in 1998/1999 and 1999/2000 seasons, respectively.