Bio-control efficiency of Bacillus thuringiensis (Berliner) against the citrus leaf miner, Phyllocnistis citrella Stainton (Lep., Gracillariidae) under laboratory conditions

The citrus leaf miner, <em>Phyllocnistis citrella</em> Stainton (Lep., Gracillariidae), is one of the most destructive pest of citrus and related Rutaceae and ornamental plants in Iran. Larvae damage leaves by creating serpentine feeding mines, which have been lead to reduce yield. Resistance and toxicity problems derived from synthetic insecticides have made it necessary to find more effective and healthier alternatives; therefore, bio-insecticides (<em>i.e</em>., <em>Bacillus thuringiensis</em>) are becoming an important component in plant protection. The aim of the present study was to evaluate the efficiency of <em>B. thuringiensis</em> against <em>P. citrella</em>. Eight <em>B. thuringiensis</em> concentrations were used against <em>P. citrella</em> L3 on orange and mortality was recorded at 1, 4, 7 and 10 days after spraying. The results showed that <em>B. thuringiensis</em> significantly affected mortality of <em>P. citrella</em>. After 1, 4, 7 and 10 days of spraying 108 concentration of <em>B. thuringiensis</em> had significantly caused the highest mortality to the pest with 59.8, 68.4, 73.6 and 77.0%, respectively. Then the mortality percent decreased until it reached 6.5, 9.5, 39.3 and 46.7% at 101 concentration, respectively. In conclusion, the study indicated that <em>B. thuringiensis</em> is effective in controlling <em>P. citrella</em> under laboratory conditions