Résumé:
Secondary plant compounds are often considered to be a defense of the producing plant
against various organisms such as pathogens and pests. These compounds are very numerous
and varied, and some are widely distributed, such as alkaloids, tannins and terpenes. In order
to search for alternatives to chemical control methods, the effect of carotenoids and
polyphenols extracted from oleander (Nerium oleander) leaves against Aphis spiraecola aphid
was evaluated under laboratory conditions. The active principles with cardiotonic activity
present in Nerium oleander are oleandrin (or folinerine), nererin and digitoxigenin. This
chemical composition makes oleander a poisonous plant involved in serious or even fatal
accidents. The results obtained revealed mortality rates of 81.97% against Aphis spiraecola
five days after treatment with the polyphenol extract with the 5% dose. For the doses of 20
and 40%, the mortality rate was 100%, and for the carotenoid the death rate was 100% five
days after the treatment. The statistical results showed a very significant variation level p =
0.00 report to the witness. The polyphenolic and carotenoid extracts of N. oleander leaves
have a strong insecticidal effect against A. spiraecola. Therefore, they can be integrated in the
fight against crop pests.
