El "gusano cogollero", Alurnus humeralis (Rosemberg) como playa de la palma africana de aceite y su combate químico en Ecuador

Abstract

The beetle Alurnus humeralis (Rosenberg) is at the present time the most serious pest of the african oil palm in Ecuador. The plantation in which the insect made its first irruption, endured a foliar damage due to larval feeding, estimated at about 30%, besides the adult’s damage in the folioles of the open or developed leaves. Preliminary tests with Heptachlor, DDT, Diazinon, Dieldrin, Metacyxchlor and Malathion against the larval stage in its natural shelter in the plant indicated that all of them are effective against larvae as measured by percentages of corrected mortality. Malathion being inferior to the others. A further field trial carried out at the farm of the Aceites Tropicales Co., in Santo Domingo de los Colorados, Pichincha province, using a randomized block design, offered a clearer picture concerning the practical control of this pest. Water diluted emulsions of Heptachlor, Toxaphene, Metacyxchlor and Malathion were used as insecticidal treatments directed to the bud of the palms by means of a Hardy high pressure pump. Treatments of Heptachlor, Toxaphene and Metacyxchlor applied at four months intervals rendered a satisfactory control, decreasing foliar damage by 82, 81 and 70% respectively, in comparison with the check. And in this trial, Malathion provided a lower degree of control, as compared with the others.