Effect of gamma radiation as a post-harvest disinfestation treatment against life stages of the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae)

Purpose: Gamma radiation is mainly used for disinfesting insect pests as an alternative for harmful fumigants. The specific dose of radiation is known to affect different developmental stages of insect pests. The study was conducted to determine the effective irradiation doses for inhibition of developmental stages and adult longevity of the coffee berry borer, Hypothenemus hampei (Ferrari).

Materials and methods: Irradiation was carried with the following doses: five levels between 0.01 and 0.16 kGy for eggs, seven levels between 0.10 and 2.00 kGy for larva and prepupa, six levels between 0.10 and 1.60 kGy for pupa and ten levels between 0.10 and 3.20 kGy for adults.

Results: Egg development was completely arrested at 0.160 kGy. A dose of 2.00 kGy caused 100% mortality in the first and second instar larva and 98.99% mortality in prepupa. The dose of 1.60 kGy prevented adult eclosion from the irradiated pupa. The adult mortality was 100% at 3.20 kGy.

Conclusion: A dose of 3.20 kGy could successfully provide complete security from all developmental stages of H. hampei and prevent yield loss in green coffee as well as the spread of the pest.

Mortality rate of egg, larva, prepupa, pupa and adult of Hypothenemus hampei at different doses of radiation.