在偏远大面积林区如苏联的西伯利亚难以及时发现松毛虫或其它害虫,以采取措施及时消灭。因此列宁格勒林业科学研究所于1946—1948年研究出了航空与地面相结合的侦察病虫害的方法。这种方法比单纯地面侦察迅速,并且成本低7—9倍。1953—1955年该所又研究出了简单的预报松毛虫大量繁殖的方法,预报使侦察方法得到进一步改善, It is difficult to find dendrolimus or other pests in time in Siberia, a large area of ​​remote forests such as the Soviet Union, so that measures can be taken to eliminate it in time. Therefore, the Leningrad Forest Research Institute in 1946-1948 developed a combination of aerial and ground detection of pests and diseases. This method is faster than simple ground reconnaissance and costs 7-9 times less. 1953-1955 the Institute has also developed a simple method of forecasting large numbers of pine caterpillars, forecasting to make reconnaissance methods to be further improved,