Abstract
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.
Graphical Abstract
Mortality rate of egg, larva, prepupa, pupa and adult of Hypothenemus hampei at different doses of radiation.
![Mortality rate of egg, larva, prepupa, pupa and adult of Hypothenemus hampei at different doses of radiation.](/cms/asset/6e6c0432-dff7-4f44-8840-7dce1ddbc9c5/irab_a_1619950_uf0001_c.gif)
Acknowledgments
We are thankful to CARRT-Mangalore University for providing radiation facility and Dr. Swaroop K for the help during radiation studies. We also thank Dr. Mandappa I.M., Coffee Board, Bengaluru, for coffee quality analysis.
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Funding
Notes on contributors
R. Kiran
Kiran R PhD Student. He received the M.Sc. degree in Applied Zoology from the Kuvempu University, Karnataka, India in 2012. He is currently pursuing the Ph.D. degree in Department of Zoology, Bangalore University. His general research interest includes the biological effects of ionizing radiation in coffee pest, Hypothenemus hampei.
K. Bhasker Shenoy
K. Bhasker Shenoy Professor of Zoology. Full Professor in the Department of Applied Zoology, Mangalore University, Karnataka, India. Area of specialization in Intestinal physiology and Radiation biology. Awardee of Commonwealth Fellowship (1999-2000) worked at Royal Free and University College Medical School, London.
Melally G. Venkatesha
Melally G. Venkatesha Professor of Entomology. Ph.D. in Entomology from University of Mysore, Karnataka, India in 1990. Full Professor in the Department of Zoology, Bangalore University, Karnataka, India. Previously worked as an Entomologist at Central Coffee Research Institute, Karnataka, India. He is a ‘Fellow of Royal Entomological Society of London’, UK. He has been working on biological control and Integrated Pest Management of coffee pests.