In an experiment of liming and potassic fertilization conducted at Mococa Experimental Station, State of São Paulo, Brazil, there was a natural infestation of caterpillars dominated by Anticarsia gemmatalis (Hbn.) (Lepidoptera: Noctuidae). Samples of the leaves of the top and the middle part of the plants were utilized for visual evaluation of the percentage of foliar area eaten. These leaves were also analysed for macro and micronutrients. The results showed that the caterpillars had preference for leaves in plots that received liming and caused more damage than without liming. Potassium fertilization did not cause any influence on the damage caused by the caterpillars on the soybean leaves.