Biological control of the turnip moth, Agrotis segetum Denis & Schiffermüller (Lep.: Noctuidae) by Bacillus thuringiensis (Bt) semisolid bait on sugar beet

The turnip moth, Agrotis segetum is considered as one of the most important pests of sugar beet. The larvae of this pest feed on sugar beet crown from the second age onwards and cut off the root from the stem causing seedling dryness. This research was conducted during 2013-15 in West Azerbaijan and Lorestan provinces. The efficacy of Bt Semisolid bait was compared with an organophosphate pesticide, Dursban in West Azarbaijan and Lorestan provinces. Four treatments including Dursban (Chlorpyrifos) EC 40.8% 2 l/ha, Bt bait (5l Bt (Biolop) + 50l water + 100 kg wheat bran)/ha, Bt (Biolop) Spray (3 ml/l), Semisolid Bt bait (100 Kg/ha) were used on the turnip moth in sugar beet fields in a randomized complete block design with four replications, in two periods of 7 and 10 day after emergence. In the province of West Azerbaijan, results of combined analysis of variance showed that the treatment of premature Bt semisolid bait with 4.3% damage had thehighest rate of damage reduction and was significantly better than other treatments. In the Lorestan province, the efficacy of Semisolid Bt bait and Dursban was better than the other treatments.