Bioinsecticidal effect of Lantana camara and Urtica dioïca grown in northeast Algeria against Plodia interpunctella (Lepidopterae: Pyralidae)

To valorize both medicinal and aromatic Algerian flora, the present study was performed to assess the effective bio-insecticidal effect of essential oils extracted from the leaves of two aromatic and medicinal plants, Lantana camara and Urtica dioica, on the development and reproduction of Plodia interpunctella (Lepidoptera; Pyralidae) found in stored foodstuffs. L. camara extracts were found to have a higher level of essential oils (1.78%) than that of U. dioica (0.95%). In addition, the essential oils of U. dioica and L. camara revealed significant insecticidal activity with mortality rate of 84.44±5.09% (U. dioica) and 72.22±6.94% (L. camara). The lethal doses (LC50; LC90) for U. dioica and L. camara were respectively, 5µL/insect; 33µL/insect, and 9.12 µL/insect; 16.94µL/insect. The reproductive effects of essential oils of U. dioica were evidenced by the extended duration of nymphal development and the preoviposition period since those of L. camara were shown by an extension of the preoviposition period, a reduction of the oviposition rate and the duration of nymphal development. Further, results showed a marked decrease in the fertility and viability of the eggs laid by females, resulting in a reduction in reproductive efficiency. Analysis of the leaf powders revealed a potential insecticidal effect, proven by an increased mortality rate of up to 100% after 72 and 96 hrs of exposure.