The lethal and sterile doses of gamma radiation on the museums pest, varied carpet beetle, Anthrenus verbasci (Coleoptera: Dermestidae)

Museums preserve historical cultural artifacts and serve as an essential resource for current and future generations seeking first-hand knowledge about the diversity of life on Earth. However, significant changes in climate from temperature and humidity cause serious biotic degradation. Despite ongoing insect control treatments, insect pests are still a major problem for museums due to the lack of suitable and unsafe environments that are provided for the storage and display of the collection. The varied carpet beetle, Anthrenus verbasci (Coleoptera: Dermestidae) is one of the major stored product pests whose larvae cause serious damage to household items and museum specimens. Therefore, this research aims to study the effect of gamma radiation on the larval, pupal and adult stages. The effects of gamma radiation have been studied on 3rd instar larvae (100, 200, 300, 400 and 500 Gy). The results showed that mortality in the larval stage significantly increased with increasing gamma radiation dose, which was reflected in the eclosion of the adult stage. The exposure of one-day-old pupae to 200, 400, 600, 800 and 1000 Gy of gamma radiation showed that the higher the dose, the lower the percentage of adult emergence. Additionally, there was a significant increase in the percentage of mortality in A. verbasci adults with increasing radiation doses when the newly emerged adults were irradiated with 200, 400, 600, 800 and 1000 Gy. The LD(50) and LD(90) of gamma radiation doses on larvae, pupae and adults were calculated, and the malformations in all stages were photographed. The fecundity and fertility of A. verbasci adults that were exposed to radiation as one-day-old pupae decreased gradually with increasing doses of gamma radiation and reached 100% sterility when exposed to a dose of 150 Gy. Among all the treatments, the sterile dose (150 Gy) or lethal dose (1000 Gy) showed superior performance over other treatments and was adjudged as the best treatments, which prevented the subsequent development and complete mortality of the pest.