Abstract
Laboratory tests using image analysis are one of the types of experimental methods in plant protection. They are used in the evaluation of crop damage by pests, also useful in testing the effectiveness of active substances of plant protection products. The most popular of these analyses are the so called “circular tests”, comprising in administering to the insects and snails the fragments of leaves and measuring the amount of consumed surface. The paper presents a method of analysis of damage to lettuce leaves using ImageJ application. The way of presenting the results was also proposed. This procedure can be used in various analyses of biological sciences and evaluating the dietary preferences of pests. Access to the application ImageJ is free, and flexible configuration allows for any setting parameters of the program, the opportunity to work in different environments and low system requirements allow you to make many accurate measurements in a short time without the need to purchase expensive specialized hardware.