CORONA DISCHARGE EFFECTS ON SOME PARASITIC INSECTS OF CULTURED PLANTS

The paper presents the results of inter-disciplinary research which de monstrates the effectiveness of a.c. corona discharges as non-pollutin g means of annihilating the pests of various cultured plants. The labo ratory tests involved the seen malt bug (Phorodom Humuli) and the comm on red spider (Tetranicus Urticae). The corona discharge was generated between a grounded plate electrode and a brush-type electrode, connec ted to a 25 kV, 50 Hz, adjustable high-voltage supply. The electrode s ystem was placed under a 63 1 glass bell, in air at atmospheric pressu re. The pest annihilation tests were carried out in two ways: direct e xposure to the corona discharge and exposure to the ionised air genera ted by corona. Immediately following the treatements effects upon the insects were at 2, 24, 48, 72, 96 hours, the following effects were ob served: paralysis/lack of motion coordination; important reduction of the digestive functions; dehydration; death (60-80% of the exposed ins ects after 48 hours; up to 99% after 72 hours). The excess of ozone ge nerated in the corona field of application is forseen, especially in d estroying the pests of the plants usually cultivated in greenhouses.