IDENTIFICATION AND BIOASSAY OF ENTOMOPATHOGENIC BACTERIAISOLATED FROM FIELD INFECTED LARVAE OF ARTOGIA RAPAE (L.) AND THEIR EFFECT ON CERTAIN BIOCHEMICAL COMPONENT OF THE LARVAE

Nine isolates of bacteria were taken from field infected larvae of Artogia rapae (L.). Two species of bacteria from the isolates were determined according to the morphological, physiological and biochemical characteristics. The identified bacteria species were, Pseudomonas mendocina Kri and Erwinia nimipressuralis Cart. In laboratory assay, the L.C50 values for both P. mendocina Kri, and E. nimipressuralis Cart, after feeding of the 2^nd instar larvae on cabbage leaves treated with different concentrations were 1.8x10^9 and 9x10^7 CFU/rnl (Colony Forming Units) respectively. The weight of 2^nd instar larvae after two days of treatment with both bacterial species was drastically decreased as compared with the untreated one. Biochemical analysis for total soluble proteins, carbohydrates and lipids in uninfected and infected larvae with entomopathogenic bacteria were studied. The obtained results from experiments of larvae treated with the above mentioned bacterial species indicated that, both amounts of soluble protein and lipids in the infected larvae were significantly increased (16.71and 21.17 mg protein and 8.65and 13.81 mg lipids /g body weight, respectively) compared with that of the uninfected larvae (5.98 mg protein and 4.41 mg lipids /g body weight). On contrast, total soluble carbohydrates of the infected larvae with both respective species of bacteria are significantly decreased, being 1.80 and 3.88 mg/g body weight, respectively compared with control (7.01 mg/g body weight).