Chemical Composition and Insecticidal Activities of Mentha Longifolia and Mentha Mozaffarianii Essential Oils against Callosobruchus Maculatus

Essential oils from two species of Mentha genus, (Mentha longifolia L. and Mentha mozaffarianii Jamzad), from the mint family Lamiaceae that grow in Iran were isolated and analyzed by GC and GC-MS and their insecticidal and repellent activities were investigated against adult cowpea beetles. Mortality rates increased with increasing of the time of exposure and concentration, where M. mozaffarianii oil showed more potent toxicity. Using the topical application, LD50s values of M. mozaffarianii and M. longifolia oils at 96 h after exposure against adults were 22.7 and 39.4 μg/adult, respectively. In the fumigant test, LC50s at 96 h after exposure was between 38.5 and 55.4 µL/L air against adults, respectively. The results demonstrated that no concentration-dependent effect was observed in the test of the repellent effect and M. longifolia oil was most repellent to C. maculatus adults at 10 µl/l air (29.00%) while M. mozaffarianii oil’s repellency was 9% at a lower concentration of 5 µl/l air. The main chemical components of the M. longifolia oil were Pulegone (48.67%), Menthone (14.31%), 1, 8- Cineole (9.37%) and Camphor (6.60%) while the major constituents of oil of the M. mozaffarianii were Piperitone (23.59%), Linalool (14.44%), 1, 8- Cineole (11.77%) and Piperitenone oxide (9.39%).