[Population structure and niche of main scale insects in jujube orchards intercropped with wheat].

To effectively control the scale insects in jujube orchards, a field study was made on the population structure and niche of Pseudococcus comstock Kuwane, Ceroplastes japonicus Green and Quadraspidiotus perniciosus Comstock in the jujube orchards intercropped with wheat in Taigu area of Shanxi Province. The results showed that at the early development stage of jujube trees, these three kinds of scale insects mainly distributed on the southeast direction of the lower and central parts of the tree crown, and P. comstock was the dominant species, with a wider breadth of two-dimensional temporal-spatial niche than the other two scale insects. At the mid-stage of jujube trees development, these scale insects mainly distributed on the northwest direction of the upper part of the tree crown, C. japonicus had a wider breadth of two-dimensional temporal-spatial niche than the other two scale insects, and the niche proportional similarity and interspecific competition of the three kinds of scale insects were not obvious. At the later stage of jujube trees development, there was no significant difference (P > 0.05) in the population structure of the three kinds of scale insects on the different parts and directions of tree crown, but the density of Q. perniciosus was bigger, and C. japonicus had a wider breadth of two-dimensional temporal-spatial niche. The average values of niche proportional similarity and interspecific competition of the three kinds of scale insects were smaller (P < 0.05) at the later development stage of jujube trees. Therefore, P. comstock should be controlled at the early development stage of jujube trees, all the three kinds of scale insects should be controlled selectively at the mid-stage of jujube trees development, and their overwinterings should be decreased by all means at the later development stage of jujube trees.

[Study on the method of skin's spectral analysis and diagnosis].

A kind of systematic structure to test skin color with optic-fiber probe is introduced. The system can be used to measure skin's reflecting spectrum by using a grating instrument system and a linear CCD sensor. According to the color theory and skin's reflecting spectrum, the formulae for calculating skin's color tri-stimulus value and chromatic error and the identified area of diseased skin's color are given. By measuring skin's surface color and reflecting spectral curve, a way to distinguish its feature, automatically and objectively, is offered. Some skin disease auto-diagnosis can be realized, comparing the reflecting spectrum and chromatic aberration of malignant skin with those of healthy skin. Good results were achieved by using this system to analyze and diagnose skin disease.