Study On The Damage And Host Adaptability Of Sesamia Inferens In The Main Wine Sorghum Producing Areas In Guizho

Sesamia inferens（walker）,a major rice pest,has rarely been reported to cause serious damage to sorghum.During a survey of insect pests in glutinous sorghum for wine production areas in Guizhou,it was found that in recent years the S.inferens has caused serious damage to local sorghum.The infestation has resulted in the withering of young sorghum seedlings,large plant failures and reduced spike rates,and has led to a significant reduction in sorghum yield and quality.Guizhou province is the birthplace and main production area of Maotai-flavor liquors,and the spirits industry is inextricably linked to sorghum production.The occurrence of S.inferens in sorghum production areas in Guizhou Province is increasing year by year,so an in-depth understanding of the biological habits of S.inferens,predicting its future occurrence and actively developing control strategies are key to effective control of emerald borer and ensuring stable and high sorghum production.In this context,this study monitored the field dynamics of the S.inferens;assessed the egg-laying preferences of the S.inferens for three host plants under choice and non-choice conditions;assessed the adaptation of S.inferens to different host plants by age-stage,two-sex life table,and provided a theoretical basis and preliminary preparation for better control.The main findings of this paper are as follows.1.Sex pheromone monitoring and overwintering survey of S.inferensS.inferens occurs in three generations a year in sorghum producing areas of Guizhou.The third generation of adult moths occurred in significantly higher numbers than the first and second generations of the stem borer in the fields,with the highest single-day moth trap for the third generation was 190,and the highest single-day trap for the second and first generations were 54 and 78,respectively;in the sorghum fields surveyed overwinter,S.inferens accounted for the largest number of all stem borer species,with values of 90.3%,indicating that in winter in the sorghum fields of Guizhou,S.inferens was the most abundant of all stem borer species in the sorghum fields in Guizhou.It prefers to overwinter within(0,5]cm range of the sorghum stalks,i.e.near the roots of the sorghum.2.Egg-laying preferences of S.inferens on three host plantsIn this chapter,the egg-laying preferences of S.inferens on maize,rice,and sorghum plants at different stages were investigated through no-choice and choice tests.In the no-choice test,S.inferensr showed the greatest preference for egg laying on maize plants at the seedling stage（174.22 eggs）,followed by rice plants at the tillering stage（137.33 eggs）,and the worst performance on maize（17.22 eggs）and sorghum（15.11 eggs）at the heaing stage.In the choice test.i.For different plants of the same growth period,S.inferens preferred to lay eggs on sorghum（66.67 grains）and maize（51 grains）at the seedling stage of plant growth,and performed less well on rice（8.67 grains）;at the jointing/tillering and heading stages of plant growth,S.inferens laid significantly more eggs on rice（84.56 grains;79.56 grains）than on the egg production on maize（7.78 grains;4.22 grains）and sorghum（4.44 grains;3.11 grains）was significantly higher than that on maize（7.78 grains;4.22 grains）.ii.For the same plants at different growth stages,in maize,S.inferens preferred to lay eggs on maize at the seedling stage（104.11 grains）,with significantly higher egg production than on maize plants at the jointing stage（63.33 grains）and heading stage（5.11 grains）;the same trend was observed for sorghum at the three growth stages（seedling stage:79.22 grains;jointing stage:50.89 grains;heading stage:2.56 grains）.Among the different growth stages of rice,S.inferens tended to lay eggs on tillering rice（95.44 grains）,followed by heading rice（87.56 grains）and the seedling rice plant（0 grains）was the worst.The results of the study showed that the females adult showed a clear tendency to select for eggs on seedling maize and tillering rice.The tendency of S.inferens to select eggs on maize,rice and sorghum plants at different times of the year was also observed.Relatively speaking,they preferred to oviposit on seedling maize and tillering rice,followed by seedling sorghum;it showed general oviposition performance on the jointing maize and sorghum,and the tasseling rice;and poor oviposition preference on the seedling rice,tasseling maize and sorghum.3.Life table parameters of the S.inferens on different host plants.Population life table experiments on maize,rice,and sorghum revealed that the S.inferens behaved differently on the three host plants.r(day^-1)andλ(day^-1)were>0and>1,respectively,indicating that S.inferens survived and completed the full developmental calendar on all three host plants.On the other hand,the mean generation period T were significant differences on the three host plant,with mean generation period T of 53.84(day^-1),49.53(day^-1)and 47.31(day^-1)for populations reared on rice,sorghum and maize,respectively.The results of this study indicate that the sorghum S.inferens was able to complete the full developmental calendar on all three host plants,with no significant differences in fecundity,but overall,S.inferens was most stable on sorghum for all biological characteristics parameters.