Three organophosphorus insecticides (malason, malatox and malatol have
the same active ingredient) and a summer mineral oil (Kz) were tested in a field
experiment to evaluate their efficiency as a single insecticide or in mixtures of Op's
and mineral oil (Kz). Pulvinaria psidii (Mask) (Homoptera: Coccidae) and Planococcus
citri (Risso.) (Homoptera: Pseudococcidae) are scale insects attacking guava and
citrus trees so that they were treated with the above treatments (four materials and
three binary mixtures). Mixtures and Kz single treatment were more effective than the
single treatment of the OP's significantly when treated on guava trees for P. psidii but
they differ significantly when studied for P. eitri. On the other hand there were no
significant differences among all of insecticides when treated on citrus for P. psidii or
P. citri so it could be concluded to use mineral oil (Kz) which is less pollute to the
environment to be used for controlling those scale insects when infest citrus.