Studies On Fumigation Activities Of Two Plant Essential Oils And The Main Components Upon The Main Stored-grain Insects

To exploit new plant fumigant,the fumigation activity of the active two plant oils upon the main stored-grain insects were tested;Analysed the main components of the plant oils,and tested the fumigation toxic effects,confirmed the effective components. Got the content of Carvone in Mentha spicata oil by gas chramotography;To considered the practical using,exploited the fumigant used the plant oil and the effective component.The results showed as follows:1.Tested the Mentha spicata oil and Mentha haplocalyx oil fumigant toxic effects on adult of Sitophilus zeamais Motschulsky,Tribolium castaneum Herbst,Rhizopertha dominica Fabricius and Cryptolestes pusillus Schonher by the method of triangle bottle obturation fumigant.At the different dosage,presented different fumigant activities,and presented the distinct difference at the different dosages(p＜0.05).The Mentha spicata oil's fumigant effect were in the order Cryptolestes pusillus Schonher＞Rhizopertha dominica Fabricius＞Sitophilus zeamais Motschulsky＞Tribolium castaneum Herbst;At the dosage was 18.75μL/L,after 24h treanment, the mortality of adult of Sitophilus zeamais Motschulsky was 97.7%and the LC₅₀ was 1.365μL/L.At the dosage was 15.625μL/L,after 48h treanment,the mortality of adult of Tribolium castaneum Herbst was 83.3%and the LC₅₀ after 24h treatment was 12.992μL/L.At the dosage was 9.375μL/L,after 48h treanment,the mortality of adult of Rhizopertha dominica Fabricius was 90.8%and the LC₅₀ after 24h treatment was 7.398μL/L.At the dosage was 0.3278μL/L,after 72h treanment,the mortality of adult of Cryptolestes pusillus Schonher was 100%.The Mentha haplocalyx oil's fumigant's effect were in the order Cryptolestes pusillus Schonher＞Rhizopertha dominica Fabricius＞Tribolium castaneum Herbst; The disposal dosage was 62.5μL/L,after 48h treatment the adult of Tribolium castaneum Herbst,the mortality was 97.8%;The disposal dosage was 5.625μL/L, after 24h treatment,the mortality of the adult of Rhizopertha dominica Fabricius was 96.6%.The disposal dosage was 0.328μL/L,after 48h treatment he mortality of the adult of Cryptolestes pusillus Schonher Fabricius was 90%.2.Confirmed the Mentha spicata oil's main component was Carvone by the MS, the Mentha haplocalyx oil's main component was Menthol,Cyclohexene was the same component in the two oils;And confirmed the content of Carvine reached 58.05%in Mentha spicata oil by gas chramotography.3.Tested the fumigant toxic effects of the three components,the Carvone presented a better effect,the fumigant effect were in the order Rhizopertha dominica Fabricius＞Sitophilus zeamais Motschulsky＞Tribolium castaneum Herbst;At the dosage was 5.625μL/L,after 72h treatment,the mortality of adult of Sitophilus zeamais Motschulsky was 92.5%,the LC₅₀ was 4.194μL/L after 24h treatment.At the dosage was 7.5μL/L,after 72h treatment,the mortality of adult of Tribolium castaneum Herbst was 100%,the LC₅₀ was 8.201μL/L after 24h treatment.At the dosage was 3.125μL/L,after 24h treatment,the mortality of adult of Rhizopertha dominica Fabricius was 98.8%,the LC₅₀ was 2.101μL/L after 24h treatment.The Cyclohexene only presented a partial effect on Sitophilus zeamais Motschulsky,at the dosage was 34.375μL/L,after 72h treatment,the mortality was 90.4%;Had no evident effect on the adult of Tribolium castaneum Herbst;The Menthol had no effects on the three insects.4.Confected three fumigants,40%Mentha spicata oil(D),20%Carvone(A)and 20%Carvone(B).Tested the stored-grain insects at 27℃,when the 40%Mentha spicata oil(D) dosage was 34.375μL/L,after 48h treatment,the mortality of adult of Sitophilus zeamais Motschulsky was 94.4%;When the 20%Carvone(A) dosage was 39.0625μL/L,after 48h treatment,the mortality of adult of Sitophilus zeamais Motschulsky was 93.1%;The dosage was 43.75μL/L,after 24h treatment,the mortality of adult of Tribolium castaneum Herbst was 96.6%;When the 20% Carvone(B) dosage was 25μL/L,after 24h treatment,the mortality of adult of Sitophilus zeamais Motschulsky was 100%,and at the dosage was 20.0625μL/L,after 24h treatment,the adult of Tribolium castaneum Herbst all dead.