IN-SITU ASSESSMENT AT SUBCELLULAR LEVEL OF THE EFFECTS OF MACROTETROLIDE INSECTICIDES ON MITES BY ELECTRON-MICROSCOPY AND X-RAY-MICROANALYSIS

Macrotetrolides, a group of microbial metabolites with high insecticid al and acaridical activity, were tested for their effects on mite Tetr anychus urticae, a plant pest. Serious damage in ultrastructure was ob served at a concentration of macrotetrolides as low as 5 mu g/ml. Elec tron microprobe X-ray analysis was used to measure the elemental conte nt in single organelles directly in situ on ultrathin sections, in bot h macrotetrolide-treated and control tissue. These two techniques (use d in concert) were complementing each other while evaluating the effec ts caused at subcellular level by these insecticidal/acaricidal agents . Comparison of their effects is thus possible for single organelles. This approach may find numerous applications in the assessment of the effects of various noxas on environment. (C) 1997 Academic Press.