Potential of plant products as protectants of stored maize against <i>Sitophilus zeamais</i> Motschulsky (Coleoptera:Curculionidae)


  • C. Conceição Universidade José Eduardo dos Santos, UJES, Huambo, Angola
  • A. Barbosa Instituto de Investigação Científica Tropical, IICT, Lisboa, Portugal
  • O. Matos Instituto Nacional de Recursos Biológicos, IP, INRB-INIA, Oeiras, Portugal
  • A. Mexia Instituto Superior de Agronomia, ISA, Lisboa, Portugal




Laboratory studies were carried out to evaluate the effects of some formulations from Mentha pulegium, Lonchocarpus sericeus, Daphne gnidium, Laurus nobilis, Momordica charantia, Nerium oleander and Ptaeroxylon obliquum as protectants against adult insects of Sitophilus zeamais on stored maize. The dusts from leaves of L. nobilis at 30% w/w caused 86% mortality and reduced F1 progeny emergence up to 57%. At the same concentration, dusts of pink flowers from N. oleander and leaves from L. sericeus reduced the F1 progeny up to 68% and 70%, reduced the developmental index and prolonged the developmental period by 4 and 6 d, respectively. The suspensions (2% v/v) from M. charantia, N. oleander and P. obliquum reduced the F1 progeny emergence up to 58, 91 and 94% and the number of holes in grains by 75, 91 and 97%, respectively. The methanol extracts were more effective than n-hexane extracts and affected the F1 progeny emergence and the developmental index.

Keywords: Sitophilus zeamais, Botanical insecticides, Repellence, Insect control agents.