Essential oils of three genotypes of Tagetes minuta, six of Tagetes patula and 15 of Tagetes erecta were screened for potential fumigant and contact toxicity against three stored product beetle species, Callosobruchus maculatus (Fabricius), Sitophilus oryzae (Linnaeus) and Tribolium castaneum (Herbst). Genotype 1 of T. minuta (TM-1), genotype 2 of T. patula (TP-2) and genotype 13 of T. erecta (TE-13) were the most toxic. These three genotypes were then evaluated for adult toxicity, oviposition deterrence, and ovicidal and population reduction activities. Essential oils of genotypes TM-1 and TP-2 induced 100% adult mortality for all three insect species at dosages of 50,000 ppm and 500 μg/insect in fumigant and contact toxicity bioassays, respectively. Adults of C. maculatus and S. oryzae were highly susceptible to the essential oils of the three genotypes in both fumigant and contact toxicity bioassays. The essential oil of genotype TM-1 deterred oviposition in T. castaneum by 81% and suppressed its egg hatchability by 91% when applied at a dosage of 70,000 ppm on filter paper.

An acetone extract of Solanum trilobatum leaves was evaluated for its ovicidal activity on the mosquito species Culex quinquefasciatus and Culex tritaeniorhynchus, by exposing eggs ranging in age from 0 to 18 h to concentrations of 50–200 ppm of the extract, and assessing their percent hatchability. A 100-ppm dose of the extract killed all of the eggs from both species aged between 0 and 6 h. The 50- and 75-ppm concentrations were also highly effective against young eggs; the effect declined in older eggs. The extract was more ovicidal towards C. quinquefasciatus than C. tritaeniorhynchus. On a testé l'activité ovicide d'un extrait à l'acétone de feuilles de Solanum trilobatum sur les deux espèces de moustiques, Culex quinquefasciatus et Culex tritaeniorhynchus, en exposant des œufs âgés de 0 à 18h à des concentrations de l'extrait compris entre 50 et 200ppm et en évaluant le pourcentage d'éclosions. La concentration à 100ppm de l'extrait tue tous les œufs d'âge compris entre 0 et 6h des deux espèces de moustique. Les concentrations à 50 et 75ppm sont également très efficaces contre les jeunes œufs, mais l'effet diminue avec l'âge des œufs. L'extrait est plus efficace vis à vis de C. quinquefasciatus que de C. tritaeniorhynchus.

l-menthol isolated from the essential oil of Mentha arvensis and seven of its acyl derivatives were tested for contact and vapour toxicity, and ovicidal and repellent activity against the storage pests Callosobruchus maculatus F., Rhyzopertha dominica F., Sitophilus oryzae L. and Tribolium castaneum Herbst. Menthyl propionate and l-menthol were highly toxic in contact assays and vapour toxicity assays respectively. l-menthol was also found to be strongly repellent (82–100% at 0.353 μg/cm2 dose) against all the insects, while menthyl acetate was highly ovicidal against T. castaneum.