Preliminary observations on trunk applications of omethoate as a selective chemical control of citrus homoptera and mites

Enrique Zúñiga S.1

ln previous tests, ornethoate controlled citrus aphids efficiently, for a period of three months, when applied to Ihe trunk. Further tests were conducted to know the effect of localized applications of non diluted omethoate against Saissetia oleae, Lepidosaphes beckii, Aonidiella aurantii, A. citrina, Aleurothrixus floccosus, Panonychus citri and Planococcus citri.
Dosages of 15 cc/adult tree gaye a 100% control of black scale, and 20 cc, of red and yellow scale, and red mite; the first dosage also gaye adequate control of mealybugs on lemon, and complete on orange trees, and of purple scale and white files, en orange trees. The only reinfestation was with rnealybugs, en lemon trees.
Results indicated that one application during summer can eliminate homopteransand phytophagous mites, when two te four sprays might be necessary otherwise to control all the species involved. Parasitized insects, reared for a couple of weeks, gaye birth te adult parasitoids, demostrating the selectivity of applications.
Care must be taken to apply the treatment aboye the grafting place, because sorne orange trunks looked susceptible te omethoate, with dosages higher than 10 cc/tree. Operators have te use gioves and be sure that the application area has the bark adhered to the trunk.

1 Subestación Experimental La Cruz (INIA), CasiIIa 3, La Cruz, Chile.