Riom, J., Goillot, C., & Fabre, J.P. 1979 [Remote sensing of Matsucoccus feytaudi (Coccoidea, Margarodidae) attacks in the maritime pine forests of southeastern France, using trichromatic microdensitometry on IR color films.]. Annales des Sciences Forestières 36: 299-320.

Notes: Title in English: [Remote sensing of Matsucoccus feytaudi (Coccoidea, Margarodidae) attacks in the maritime pine forests of southeastern France, using trichromatic microdensitometry on IR color films.] Scale population levels and signs of attack were investigated on individual trees of various Maritime pine stands which were selected for the development of a remote sensing investigation method using small scale (1/250; 1/500; 1/2500), low altitude IR color photography (37, 75 and 375 m). Tree crowns were analyzed by means of trichromatic microdensitometry; the optical density of green (dv) and blue (db) layers indicates the degree of attack. Healthy trees have high dv and db values (1.8 and 2); heavily infested trees have low dv and db values (1.2 and 1.3); trees undergoing an attack produce values between these two extremes. The red film layer (i.e., sensitive to IR) does not indicate the degree of attack. Trees were distributed into six classes. The IR color digitized film with 256 levels using trichromatic densitometry is processed through an interactive unit based on micro-processing. This allows automatic classification and quantifying corresponding to various degrees of attack in the stands.