Studies on the effectiveness and utilization of systemic insecticides upon the injurious insects of citrus trees I

Abstract

The author carried out some experiments, on the effectiveness of three systemic insecticides (Pestox 3, Systox, Sodium selenate) by soil and foliage application upon the citrus red mite (Metatetranychus citri MCG.), and toxicity of Pestox 3 and Systox to the 7-spotted ladybird (Coccinella septempunctata bnuckii MULSANT). Results obtained are summarized as follows. 1. When three systemic insecticides were wat-ered with water solution on potted Yuzu plant for control citrus red mite, Pestox was most effecti-ve, and the residual action of from 0.075 to 0.15 per cent water solution of this material was con-tinued for 3 months or more after the treatment. Systox was less effective than the Pestox 3, and the residual effect was lost after 11 or 12 weeks. Sodium selenate was little or no effect. The foliage treatments of Pestox 3 and Systox were less effective than their soil treatments. 2. When Pestox 3 and Systox were applied to the fo lige on yo ng Citrus tree in field, both Pestox 3 and Systox gave good control of the citrus red mite, and 0.075 per cent water solution of each material maintaining control for a peiriod of 6 or more weeks after treatment even under condition of heavily infestation of mites. 3. Pestox 3 was nontoxic to the 7-spotted ladybird (Coccinella septempunctata bnuckii MULSANT), but Systox was found highly toxic.