To reduce the dependence on the sometimes unwise use of synthetic pesticides in fruit and vegetable plantations, the toxicity
and repellence of
Peganum harmala
L. (Zygophyllaceae) acetonic seed extract was assayed against several insect pests.
For contact toxicity, 3- to 4-d-old individuals of
Aphis fabae
Scopoli,
A. gossypii
Glover,
A. nerii
Boyer de Fonscolombe,
and
Myzus persicae
(Sulzer) were included, as well as 1- to 7-d-old adult
Tribolium castaneum
(Herbst). Repellent effect
experiments were conducted on adult, 1- to 2- and 3- to 4-d old
M. persicae individuals. At 60 mg mL
-1, the topical bioassay
mortality percentage was significantly higher in
A. gossypii than in
A. fabae and
A. nerii after 12-72 h. Mortality of the
treatments on
M. persicae was 87.1% and 90.0% after 24 and 48 h, respectively, and significantly higher than
A. fabae and
A. nerii during this period. At 60 mg mL
-1, the mortality of
T. castaneum was much lower than that of the aphid species. The
highest repellent index (over 72%) was observed on 1- to 2-d-old
M. persicae individuals.
