Study On Bioactivity Of Acorus Calamus Rhizome Against Blattella Germanica And Product Of Killing Cockroach

Insecticidal activity of different solvents and methods extracts of Acorus calamus (Araceae) rhizome against Blattella germanica (Dictyoptera: Blattellidae) were investigated, respectively. The optimal extraction of Acorus calamus rhizome active ingredients was found in supercritical fluid (CO₂) extract, contact, stomach poisoning, repllency and fumigation activity of Acorus calamus rhizome against Blattella germanica were studied, respectively. Fipronil presented significantly the highest activity by compared with tested chemical pesticides, joint action and emulsifiable solution product of the mixtures of Acorus calamus rhizome supercritical fluid (CO₂) extract and fipronil were evaluated, respectively. The results were as follows.1. Yield rate of Acorus calamus rhizome extracted by five kinds of different solvents soakage extract, soxhlet extract, ultrasonic extract, supercritical fluid (CO₂) extract was compared. The results showed traditional methods of soakage extract (except petroleum ether extract) and soxhlet extract produced higher rate than modern technology of ultrasonic extract and supercritical fluid (CO₂) extract. The highest and the lowest yield rate of Acorus calamus rhizome metabolize products were observed in methanol soakage extract (9.23%) and ultrasonic extract (2.55%), respectively.Insecticidal activity of five kinds of different solvents and four kinds of methodsextracts of Acorus calamus rhizome against third instar larvae and adult male of Blattella germanica were researched, respectively. Firstly, insecticidal activity of the petroleum ether, chloroform, ethyl acetate, ethanol, and methanol soakage rhizome extracts of Acorus calamus were compared against Blattella germanica, methanol soakage extract produced the highest mortality. The third instar larvae and adult male corrected mortality were 97.3% and 100% treated by 22 mg/ml, after 120 h of exposure. In succession, insecticidal activity of four methods extracts of Acorus calamus rhizome against Blattella germanica were studied, respectively. Supercritical fluid (CO₂) extract presented significantly the highest activity, the third instar larvae and adult male corrected mortality were 96.25% and 78.75% treated at the concentration of 10 mg/ml, 24 h later.Contact, stomach poisoning, repllency and fumigation activity of Acorus calamus rhizome supercritical fluid (CO₂) extract against third instar larvae of Blattella germanica were studied, respectively. The outcomes indicated Acorus calamus rhizome extract represented significantly contact and repllency effect but showed no or less stomach poisoning and fumigation effect against Blattella germanica in the test. Contact effect of Acorus calamus rhizome supercritical fluid (CO₂) extract against third instar larvae of Blattella germanica was studied with drug film method. The corrected mortality were 98.33% and 100%, at 18 mg/ml, 12 and 24 h later, respectively. Repllency effect of Acorus calamus rhizome supercritical fluid (CO₂) extract against third instar larvae of Blattella germanica was studied with filter paper drug film method. The Acorus calamus extract showed 67.73% repellency at 815.28μg/cm², the repellency level reached classâ…£.2. Knockdown and contact activity of deltamethrin, fipronil, avermectin, imidacloprid against third instar larvae and adult male of Blattella germanica were researched, respectively. Firstly, using contact drug film method, Knockdown effect of four kinds of chemical pesticides was tested, knockdown activity of pesticides, from high to low, was deltamethrin > fipronil > avermectin > imidacloprid. KT₅₀ of pesticides on third instar larvae and adult male of Blattella germanica, deltamethrin was 10.514 min and 8.997 min, fipronil was 99.653 min and 244.046 min, avermectin and imidacloprid were over 360 min, respectively. Secondly, at the concentration of 0.1, 0.05, 0.01 mg/ml, contact activity of deltamethrin, fipronil, avermectin, imidacloprid against third instar larvae and adult male of Blattella germanica were studied, respectively. Fipronil showed significantly the highest activity, followed by deltamethrin, avermectin, imidacloprid. Linear regression equation and LC₅₀ of fipronil on third instar larvae of Blattella germanica after 24 h treatment were (?)=0.976+3.376x and 0.543μg/ml, respectively.3. Joint action of the mixtures of Acorus calamus rhizome supercritical fluid (CO₂) extract (A) and fipronil (B) was evaluated. Co-toxicity coefficient (CTC) of nine kinds of ratio of mixture were all over 120, the mixture showed obvious synergistic action. The results showed mixture manifested the best synergistic action when volume ratio value of A:B was 3:7, CTC reached 1058.896.4. 30 percent emulsifiable solution production formula of the mixtures of Acorus calamus rhizome supercritical fluid (CO₂) extract and fipronil was as follows, the ratio of mixture of Acorus calamus rhizome supercritical fluid (CO₂) extract and fipronil, main solvent (butanol), assist solvent (ethanol), emulsifier (OP-10) was 30:35:15:20.