ABSTRACT
Background & objectives: Resistance amongst cockroaches has been reported to most of the spray insecticides apart from the problem of food contamination and inconvenience. Gel baits which can be selectively applied have been found effective in control of cockroaches in laboratory studies but very few field studies are available. This trial was planned to evaluate the efficacy of fipronil (0.01%) and imidacloprid (2.15%) gels over synthetic pyrethroid (0.02% deltamethrin + 0.13% allethrin) and propoxur (2%) aerosols in control of cockroaches in the field. Methods: Survey was done to find out pre-treatment density in catering establishments and houses by visual count and sticky trap methods. A total of 10 catering establishments and 10 houses having high cockroach infestation were selected by sampling (two catering establishments and houses for each insecticidal treatment and two for control). Propoxur and synthetic pyrethroid aerosols were used for spraying the infested sites once only. Single application of fipronil and imidacloprid gels was used as crack and crevice treatment. Visual count method gave better indications of cockroach infestation as compared to sticky trap method, hence, the same was followed for post-treatment evaluation every week up to 12 weeks. Results: Synthetic pyrethroid could not bring about the desired reduction in cockroach infestation in the present study. Single application of fipronil gel was able to reduce cockroach infestation up to 96.8% at the end of 12 weeks whereas imidacloprid application resulted in 90.9% reduction and propoxur resulted in 77.5%. However, propoxur was more effective in reducing the cockroach density by first week in comparison to imidacloprid and fipronil gels but its efficacy started declining after 8th week. Difference was found statistically significant by Kruskal-Wallis H-test. Conclusion: The study reports the efficacy of propoxur aerosol, imidacloprid gel and fipronil gel baits for control of cockroaches.
ABSTRACT
A field trial on the control effect of fipronil poison bait against German cockroaches (Blatella germanica) was carried out at different restaurant types in Sinchon, Seoul, Republic of Korea. Monitoring was performed applying food baited traps for 2 days per week. Reduction rates of German cockroaches by applying fipronil baits were 90.9% at Korean restaurants, 96.4% at Chinese restaurants, and 89.4% in beer hall kitchens after 4 weeks of the treatment. Overall average of the reduction rate was 93.9%. As the natural reduction rate at untreated restaurants was 11.5% after 4 weeks, a correction of the average reduction rate by applying the Abbot formula was 93.1%.
Subject(s)
Animals , Pyrazoles , Insecticides , Insect Control/methods , CockroachesABSTRACT
Objective To study the therapeutic effect on murine allergic asthma with recombinant Bla g 2(rBla g 2) allergen and its possible mechanism.Methods Eighteen BALB/C mice were randomly divided into three groups:normal control group(group A) , asthma model group(group B) , and recombinant protein rBlag2 treatment group(group C).Mice in groups B and C were subcutaneously immunized weekly with rBla g 2(50 mg) formulated in Al(OH)3 adjuvant for three weeks.Group A received only adjuvant emulsified with normal saline.Two weeks after the last inoculation, mice in group C were administered each with rBla g 2(100 mg) /dose, and groups A and B were given PBS.All the mice received eight doses at 2-day intervals.One week after the last immunotherapy, mice in groups B and C were intranasally challenged with 50 mg rBla g 2 daily for seven days, while mice in group A received PBS.Twenty-four hours after the challenge, the following items were examined:airway hyperresponsiveness of mice, total cellular score and cell classification in bronchoalveolar lavage fluid(BALF) , level of rBla g 2-specific IgE and IgG2a in serum, lung inflammation by HE stain, and Bcl-2 expression of eosinophils of lung by immunohistochemistry.Results Compared with group B, group C showed a decreased Penh value of airway hyperresponsiveness(P