EVALUATION OF Coccinella undecimpunctata L. AGAINST Brevicoryne brassice (Linnaeus) ON DILL PLANTS

Abstract

Field experiment was conducted at El-Fayoum Governorate during two successive seasons 2007and 2008 to study the population fluctuation of Brevicoryne brassice (Linnaeus) and Coccinella undecimpunctata L. and evaluation of C. undecimpunctata against B. brassice. Moreover, to evaluate the effect of certain weather factors (daily mean temperature, daily mean R.H.) on the pest and predator on Dill plant. The obtained data revealed that, the mean number of aphid species individuals began to appear on January and population increased to reach the maximum average on April during 2007 season. In the second season, the infestation of the individuals started to appear at the last week of December The mean number increased gradually to record two highly peaks on March and April The correlation between population fluctuation of aphid species and means of weekly (max., min. and mean Temps.) was positive and significant during 2006/2007 and 2007/2008 seasons. In addition, the correlation between insect infestation and mean of relative humidity was negative significant correlation during 2006/2007 and 2007/2008 seasons. Generally, mean of the total number of C. undicempunctata was higher in the second season than the first one. Releasing of C. undecimpunctata at rate 6 adult/ 2 m 2 gave the best reduction of aphid individuals recording general mean reduction percentage 93.14%. Followed by the second level (4 adult / 2 m 2 ) this suppressed the population by 85.62% and the low level (2 adult / 2 m2) with 81.86%, respectively.