The viability of the use of an image analyzer (scanner), was compared with the use of leaf weight and planimeter techniques, to measure leaf area consumption by insects. The tests were conducted with 5th instar Anticarsia gemmatalis Hübner (Lep.: Noctuidae) larvae reared on artificial diet. Soybean leaves (cultivar "IAC - 8") were offered to velvetbean caterpilars held in Petri dishes. Two experiments were conducted in a completely randomized design: (1) with whole soybean leaves, and (2) with leaf disks. The image analyzer use was compared with the leaf weight method in the first experiment and with the planimeter. The image data was analyzed with PCXAREA software. There were no significant differences between the image analyzer and the standard techniques. The evaluation time with image analyzer reduced by 88.5 and 87% the time consumed with planimeter and leaf weight methods, respectively. Based on the results, it is concluded that the use of a scanner is viable for measuring leaf area consumption by insects.
Insecta; leaf area consumed measurement; velvetbean caterpillar; scanner