Abstract

The hazards caused by large scale use of insecticides for: the control of crop pests have focussed the attention of investigators to switch over to other alternative methods involving minimum risks: One of the recent developments in this direction is the use of antibiotics and sulphanilamides which are reported to induce sterility in insects either by contact or when ingested along with the plant, by interfering with the normal physiology of the insect. The first report on the possible use of these substances in the control of crop pests was made on recently by Harries (1961) in two spider mites viz., Tetranychus telarias (L) and Panomychus ulmi (Koch), Harries and Mattson (1963) extended the use of antibiotics against the aphids Myzus persicae (Sulz) Aphis pomi De Geer and Macrosiphum pisi (H). Later workers like Ehrhardt and Schmutterer (1966), Jayaraj and Schmutterer (1966), Ehrhardt et al., (1966) and Jayaraj et al., (1967) established that certain antibiotics and sulphanilamides have got irreversible effect in Aphis fabae. Scop and that sterility can be induced to the progenies indicating the possibility of permanent control. These authors attributed the effect to the destruction of symbionts in the insect.

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