GAMMA RADIATION EFFECTS ON DIFFERENT DEVELOPMENT STAGES OF COFFEE BERRY BORER Hypothenemus hampei FERR. 1867 (COLEOPTERA SCOLYTIDAE)

Abstract

An experiment was conducted at the “CENTRO DE ENERGIA NUCLEAR NA AGRICULTURA” of the Escola Superior de Agricultura “Luiz de Queiroz” — USP — Piracicaba, São Paulo, Brazil, to study the control of the coffee berry borer Hypothenemus hampei Ferr., 1867, using gamma irradiation from a source of Cobalt 60. The lethal dosage necessary for the adults outside and inside the grains were 475 an 525 krad, respectively. It was also evident that there was absorption of radiation by the grains. For larve the lethal dose was 350 krad and for pupas 400 krad. A mixed group of the coffee berry borer were treated with 15 krad. The larve lived for 21 days; the pupas l5 days however the adults were the most resistant living for 60 days after treatment. Up to now we have not made efforts to observe the progeny, however sterile dosage is greater than 15 krad. According to the results obtained it is concluded that the best range of treatment for the coffee berry borer is between 25 and 50 krad. Using that range adults were controlled in 36 days. The phases which do the most damage, larval and adult, stopped eating 3 days after treatment.