New Study On New Attractants Of Larvae Of Lasioderma Serricorne(Fabricius) And Ephestia Elutella(H(?)bner)

Lasioderma serricorne(Fabricius)and Ephestia elutella(Hübner)are the most common pests in the process of tobacco processing and storage,and the main loss of tobacco is caused by larval stage damage.Therefore,it is of great significance to effectively detect and monitor the occurrence state of the larvae of these two kinds of tobacco storage pests and predict the insect situation for the scientific management of tobacco storage pests.In this study,the third instar larvae of L.serricorne and E.elutella were selected as the research objects,and 7 tobacco varieties,16 plant odor sources and 6 chemical odor sources were selected as the test materials.Substances with attracting effectiveness on the larvae of the two tobacco storage pests were screened by "free choice method","trap" two-way selection method and "Y" olfactometer test.Based on this results,the attractiveness of different types and proportions of the screened substances on the larvae of the two tobacco-storing pests were further studied,and the attractants of the two kinds of tobacco-storing pest larvae were prepared and verified in a simulated warehouse.Finally,HS-SPME-GC-MS technique was used to extract,separate and identify the volatile components of the prepared attractants with strong attractiveness.The results of the study are as follows.When the odor perception experience was the same,the response rate of tobacco leaf selection of different varieties of L.serricorne larvae was significantly different,as did E.eliutella larvae.When L.serricorne larvae and Ephestia elutella larvae feed on the same varieties of tobacco leaves,the selection response rates before and after odor perception increase,but there was no significant change.Under the same conditions,L.serricorne larvae were most harmful to Yunnan Y068 and Hunan 20Y965,E.eliutella larvae were most harmful to Yunnan Y068 and Guizhou Y113,and L.serricorne and E.eliutella larvae were the least harmful to Heilongjiang Y417.The feeding preference of L.serricorne and E.eliutella on the seven kinds of tobacco leaves was relatively stable.The odor sources of plants and compounds that had a strong attractiveness on L.serricorne larvae were pepper,thyme,angelica,linoleic acid,corn essence,green tea,cooked soybean oil,distiller’s yeast,rapeseed oil,soybean powder,and their behavioral selection coefficients were all greater than 40%,among which angelica and pepper had significantly higher insect attractiveness than tobacco leaves.The odor sources of plants and compounds that had a strong attractiveness on E.eliutella larvae were broken wheat,oleic acid,linoleic acid,flour,pepper,angelica,peanut oil,rapeseed oil,thyme,cooked soybean oil,koji,grape seed oil,green tea,rice bran oil,its attractiveness coefficient was greater than45%,and crushed wheat,oleic acid,linoleic acid,grapeseed oil,rapeseed oil and camellia oil had significantly higher insect attractiveness than tobacco leaves.The attractiveness of pepper,thyme,angelica,green tea and wine koji on L.serricorne larvae increased with the increase of the odorant dose.The attractiveness of oleic acid,linoleic acid,rapeseed oil and grape seed on E.eliutella larvae were enhanced with the increase of the concentration of odorant.The attractiveness of corn essence on E.eliutella larvae increased with the decrease of mass concentration,and the optimum mass concentration was between 1.0 and 10.0 g/L.The attractiveness of the compound attractants on the larvae of the two tobacco-storing pests was significantly higher than that of the single attractants.The percentage of ingredients in the formula A of the best attractant for L.serricorne larvae was: Angelica 10%,thyme 10%,wine koji 10%,pepper 10%,green tea 10%,Yunnan Y068 50%.In addition,adding 3.3% honey water and 2.8% white vinegar had a synergistic effect on the food attractants of L.serricorne.The percentage of ingredients B of the best attractant formula for E.eliutella larvae was: corn essence 14.4%,linoleic acid 28.8%,oleic acid 7.2%,grapeseed oil 1.9%,rapeseed oil 14.4%,Yunnan Y068 33.3%.Adding 1.6% honey water,3.0% white wine and 1.2% sesame oil has synergistic effect on E.eliutella food attractant.The optimum attractant mass ratios of L.serricorne and E.eliutella food attractants and tobacco leaves were 40:1 and 25:1,respectively.The best lure effect was in the range of 25 and 75 cm.Under the simulated real warehouse conditions,the maximum trapping rates of the food attractants for L.serricorne and E.eliutella larvae were 76.0 and 84.0%,respectively.Food attractants of L.serricorne were extracted and analyzed by HS-SPME-GC-MS technology,there were 62 main volatiles in the two kinds of food attractant,including alkanes,alkenes,aldehydes,alcohols,ketones,esters,alkalis,etc.And alkalis and alcohols accounted for the largest proportion.The composition and content of volatile components of the two food attractants were similar,and 44 kinds of substances were detected.The most abundant ones were: nicotine,1-methyl-2-(3-pyridyl)pyrrole,celery,(Z)-9-tetradecen-1-ol,2-phenylpentane,vitamin E.Food attractants of E.eliutella were extracted and analyzed by HS-SPME-GC-MS technology,there were 13 main volatiles in the two kinds of food attractant,including fatty acids,alkalis,ketones,aldehydes,etc.And fatty acids and alkalis account for the largest proportion.The composition and content of the volatile components of the two food attractants were similar,and 11 substances were detected.The most abundant ones were: linoleic acid,nicotine,parsley,2-phenylpentane.