Bioactivity of some plant extracts against the lesser grain borer, Rhyzopertha dominica (Fabr.) (Coleoptera: Bostrichidae)

Résumé

The lesser grain borer, Rhyzopertha dominica (Fabr.) is an important insect pest of stored cereals in the world. Plant extracts from Acacia nilotica, Artemisia annua L. and Thuja orientalis were tested for their insecticidal activities against this pest. Contact on surface of a Petri dish and ingestion with wheat grains methods as well as, combinations of mixture of these extracts were used against R. dominica adult. Plant extract of A. annua had higher mortality of R. dominica adult than other tested extracts. The mixtures of  A. annua with  A. nilotica or T. orientalis are converted to more toxic metabolites against R. dominica adult than each plant extracts alone. Understanding the mechanism of mixture of plant extract to enhance activity of them can facilitate the creation of artificial blends that optimize their efficacy against insect pests.