Efficacy of fresh crushed leaves and essential oil of Eucalyptus camaldulensis Dehnh on larvae of Dermestes maculatus De Geer insect damage to smoked dried Sardinella aurita "Kétiakh" stored in Senegal

Abstract

Synthetic pesticides used to protect stored smoked and dried fish often cause enormous damageto human health and the environment. To limit the harms due to the use of these chemicals, it is necessary to find alternative methods. For this purpose, natural substances may constitute a beneficial way. The objective of this work is to study the effect of crushed fresh leaves and essential oil of Eucalyptus camaldulensis on the mortality of the
larvae of an insect pest of smoked and dried fish, Sardinella aurita "Kétiakh", Dermestes maculatus (De Geer, 1774). Essential Oil was obtained by steam distillation from Eucalyptus leaves (0.8% w/w) and analyses carried out by GC/FID and GC/MS. For the biological test, fresh crushed leaves and essential oil were tested at different doses at varying treatment times again larvae Dermestes maculates. The results showed that D. maculatus was sensitive for both fresh crushed leaves and the essential oil, the efficacy of which depended on the dose and duration of treatment. The doses of 2 g and 2.5 g of freshly ground leaves showed a high efficiency of 27 to 40%, of mortality respectively. However, for the essential oil, with the increase in the duration of exposure, the highest mortality (33.3%) was recorded after 72 hours of treatment with the 40µl dose and at 120 hours with the 60µl dose. This study showed that fresh crushed leaves and essential oil of Eucalyptus camaldulensis can be considered as an alternative to the use of chemical insecticides in the conservation of smoked and dried Sardinella aurita "Kétiakh" stored in Senegal.