Population Ecology And Toxicology Of Control Atmosphere Against Pest In Stored Chinese Medicine Material

Drugstore beetle Stegobium paniceum,cigarette beetle Lasioderma serricorne and coffee bean beetle Araecerus fasciculatus,the most important three members of pests to destroy stored Chinese medicinal materials(CMM),are dominant populations in stored CMM insect community. Breeding of these pests are responsible to the quantity discarding as useless of CMM,decreasing of medicine power even to become garbage.In the present paper,the population ecology of the three pests were investigated in laboratory with given CMM host.The habit and the influence of ecological factor(temperature) on both the development and propagating of the pests were investigated.Whilst,the practice of carbon dioxide enriched atmosphere was carried out in management of pests in CMM.Some key information which are important to kill stored CMM pests was supplied.What's the most important is that toxicologically and biological characteristic of Carboxylesterases(CarE),Acetylcholinesterase(ACHE),Acid Phosphatases(ACP) & Alkaline Phosphatases(ALP),Superoxide Dismutase(SOD) and Glutathione Transferase(GSTs) from the three pest above were investigated.The current research presented some important and basic information to the research in toxicology of control atmosphere and related fields.The main results are as followed.The population ecology of pest in stored CMM1.The threshold temperature of development of drugstore beetle egg,larvae and pupae was 5.05,6.00 and 8.36℃respectively,and the accumulation temperature was 177.9,939.8 and 153.7 day degree.The threshold temperature of development for cigarette beetle egg,larvae and pupae was 16.5172,11.07 and 11.78℃respectively,and the accumulation temperature was 89.59, 669.53 and 137.12 day degree.The threshold temperature of development for coffee bean beetle egg,larvae and pupae was 9.60,11.48 and 7.60℃respectively,and the accumulation temperature was 135.51,523.57 and 157.10 day degree.2.In Guiyang,there are generally 3～4 generations per year in stored CMM for drugstore beetle.Overwintering may be passed in the older larval stage.There are generally 4～5 generation per year in stored CMM for cigarette beetle.Overwintering may be passed in the 4^th generation older larval stage or the 5^th generation younger larval stage.There are generally 3～4 generations per year in stored CMM for coffee bean beetle.Overwintering may be passed in the older larval stage with a few adults or pupae stages.3.Temperature was a key ecological factor to the development of both drugstore beetle, cigarette beetle and coffee bean beetle.Three insects can finish the reproduced and developed at the temperature of 17 to 35℃.However,The more great powerful reproduced and the better development speed at higher temperature were noted in our research.The toxicity of carbon dioxide enriched atmosphere to pest in stored CMMThe toxicity of control atmosphere with different CO₂ levels to pests in stored CMM were investigated.The LT₅₀(the half lethal exposure periods),LT₉₉(the complete lethal exposure periods) and toxicological regress equation were calculated which could be use in practice of pest control base on the Goodness-of-Fit chi square test.1.The mortality rate was 55.56±6.94,58.89±8.39 and 58.89±5.09%respectively when the three experimental pest drugstore beetle Stegobium paniceum,cigarette beetle Lasioderma serricorne and coffee bean beetle Araecerus fasciculatus was exposed to the control atmosphere with 10%CO₂ for 24 h.And The LT₅₀ was 22.39,23.21 and 21.15 h respectively.However,the higher mortality rate was noted when the pest was exposed to the control atmosphere with 30% CO₂ or higher level within a shorter exposure periods.2.Results showed that experimental pests exposed to control atmosphere with 30%CO₂ or more could be killed within 45 h.Tempreture and CO₂ levels or other composing and exposure period are some key factors to control pest with control atmosphere.The toxicologically and biological characteristic of some key enzymes in pests exposed to the CO₂ enriched atmosphere1.Compared to control,the specific activity of CarE from drugstore beetle which was exposed CO₂ enriched atmosphere for 3 h,6 h and 9 h increased 7.81%,14.96%and 22.58% respectively.That of cigarette beetle exposed for 3 h decreased 3.18%and for 6 h increased 22.2%. That of coffee bean beetle exposed for 3 h,6 h increased 31.75%and 50.82%respectively.Whilst, both the K_m and V_max of CarE from the pest mentioned above were affected by the press of CO₂ enriched atmosphere.2.The specific activity of AChE from drugstore beetle and cigarette beetle which was exposed CO₂ enriched atmosphere for 6 h and 9 h decreased from 14.29μmol/L and 30.39μmol/L to 1.83μmol/L and 7.63μmol/L respectively.However,this treat did not continue with the prolonging of exposure periods.The K_m and V_max of AChE from dugstore beetle and cigarette beetle were affected by the press of CO₂ enriched atmosphere.3,Compared to control,the specific activity of ACP from larvae of drugstore beetle and coffee bean beetle which were exposed to CO₂ enriched atmosphere for 6 h increased 78.59% and 72.45%respectively.The specific activity of ALP changed when the larvae of drugstore beetle were exposed to control atmosphere for 0～6 h.4,The activity of SOD from drugstore beetle,cigarette beetle and coffee bean beetle which were exposed to CO₂ enriched atmosphere for 6 h increased from 2.011±0.954,2.664±0.218 and 1.458±0.718 to 3.135±0.105,3.050±0.673 and 2.975±0.229 enzyme unite/pest/30 min.