Abstract
Dermestes maculatus infestation is a major threat to the quality of smoked fish. It results in reduced nutritional value and economic losses. This study explores the effect of salt treatment on the development of D. maculatus in smoked Catfish (Clarias gariepinus) and Tilapia (Oreochromis niloticus). The study was conducted in the Volta Region of Ghana. Fish samples were purchased from five major processing sites (Kpando, Kwame Krom, Dambae, Abutuase, and Jemeni). Salt content of smoked samples was determined using the Mohr method, while fresh fish sample were immersed in varying salt concentrations (0%, 5%, 10%, 15%, 20%, and 25%), smoked before exposure to adult D. maculatus under controlled laboratory conditions for 68 days. Results showed that salt concentrations in smoked fish samples ranged from 16.0% in Abutuase to 22.8% in Jemeni, exceeding WHO-recommended sodium limits. There was a significant reduction in egg laying as salt concentration increases. In Catfish, mean egg counts dropped from 58.3±42.7 at 0% to 11.3±16.3 at 20%, while in Tilapia, egg counts decreased from 20.3 ± 9.0 at 0% to 8.00±8.5 at 20%. Salt treatment was more effective in Tilapia, which recorded lower egg counts compared to Catfish. Although salt concentration did not significantly affect egg to larva development, it inhibited larva to adult emergence with 0.0% adult emergence recorded at 25% salt concentration in both species. Weight loss decreased with increase in salt levels, from 60.0% at 0% to 14.0% at 25% in Catfish. These findings confirm that salt is effective against D. maculatus infestation through inhibition of its reproductive capacity and limiting adult emergence. However, the high salt levels used may raise public health concerns.