Objective: To test the effectiveness of conidial spore formulations [Aspergillus tubingensis(A.tubingensis) and Trichoderma harzianum(T.harzianum)] against tropical bed bugs, Cimex hemipterus.Methods: Spore formulatio...Objective: To test the effectiveness of conidial spore formulations [Aspergillus tubingensis(A.tubingensis) and Trichoderma harzianum(T.harzianum)] against tropical bed bugs, Cimex hemipterus.Methods: Spore formulations were made from two fungal strains, T.harzianum and A.tubingensis.The bed bugs were exposed to the conidial spores placed soaked onto a fabric cloth for 1 h and the mortality counts were recorded daily until 14 days.Results: Mean survival times based on Kaplan–Meier survival analysis showed no significant differences between all the concentrations in both the fungal isolates:T.harzianum and A.tubingensis.However, the evaluation of both the isolates in terms of virulence resulted in low lethal hours in all the concentrations except for the high concentration of A.tubingensis(LT_(50)= 44.629 h) at the conidial exposure of 1 × 10~6 spores/mL.Rapid mortality of the bed bugs was observed from Day 6 to Day 12, ranging from 13% to 90% in all three concentrations of A.tubingensis.With reference to the T.harzianum exposure, the concentration of 1 × 10~4 spores/mL displayed a gradual increase in the percentage mortality of 90 on Day 14.Conclusions: Approaches to the bed bugs treatment should be explored in-depth using a natural biological agent like fungus especially A.tubingensis to reduce this pest population, in order to replace chemical methods.展开更多
Desiccant dusts have been shown to be effective materials in the management of bed bugs(Cimex spp.).Past research primarily focused on exploring the direct lethal effect of dusts against bed bugs,whereas information o...Desiccant dusts have been shown to be effective materials in the management of bed bugs(Cimex spp.).Past research primarily focused on exploring the direct lethal effect of dusts against bed bugs,whereas information on their sublethal effects on bed bugs are limited.In this study,we evaluated the lethal effect of 3 dust products(Johnson's®Baby powder,Vazor DE powder^(TM),and CimeXaTM;abbreviated as Baby powder,DE,and TM CimeXa)against the tropical bed bug,Cimex hemipterus(F.),under laboratory conditions.Results showed that the 3 dust products caused 97%100%mortality to tropical bed bugs within 14 d,both in no-choice and choice experiments.However,in a brief exposure experiment(crossing a 2.5-cm-wide band),Baby powder exposure caused a significantly lower mortality(23%)than DE(88%)and CimeXa(100%).The more effective dusts(DE and CimeXa)were selected for further evaluation of their sublethal effects on C.hemipterus.DE and CimeXa caused significantly higher mortality(48%58%)through horizontal transfer than that of control(6%).Brief exposure to DE and CimeXa dusts did not affect tropical bed bug activity and their response to CO_(2).However,CimeXa-exposed tropical bed bugs exhibited reduced feeding and lowered survival rate after feeding.Moreover,both DE and CimeXa dust bands showed strong barrier effects on the crawling of tropical bed bugs.Our results indicate that both DE and CimeXa have great potential for preventing C.hemipterus from reaching protected areas and for controlling C.hemipterus.展开更多
基金Supported by Universiti Sains Malaysia(Grant No.304/PBIOLOGI/6313030)
文摘Objective: To test the effectiveness of conidial spore formulations [Aspergillus tubingensis(A.tubingensis) and Trichoderma harzianum(T.harzianum)] against tropical bed bugs, Cimex hemipterus.Methods: Spore formulations were made from two fungal strains, T.harzianum and A.tubingensis.The bed bugs were exposed to the conidial spores placed soaked onto a fabric cloth for 1 h and the mortality counts were recorded daily until 14 days.Results: Mean survival times based on Kaplan–Meier survival analysis showed no significant differences between all the concentrations in both the fungal isolates:T.harzianum and A.tubingensis.However, the evaluation of both the isolates in terms of virulence resulted in low lethal hours in all the concentrations except for the high concentration of A.tubingensis(LT_(50)= 44.629 h) at the conidial exposure of 1 × 10~6 spores/mL.Rapid mortality of the bed bugs was observed from Day 6 to Day 12, ranging from 13% to 90% in all three concentrations of A.tubingensis.With reference to the T.harzianum exposure, the concentration of 1 × 10~4 spores/mL displayed a gradual increase in the percentage mortality of 90 on Day 14.Conclusions: Approaches to the bed bugs treatment should be explored in-depth using a natural biological agent like fungus especially A.tubingensis to reduce this pest population, in order to replace chemical methods.
基金supported by the Ningbo Key Research and Development Plan and"Jie Bang Gua Shuai"Program(2022Z124)the Foreign Expert Project of the Ministry of Science and Technology of China(G2023030035).
文摘Desiccant dusts have been shown to be effective materials in the management of bed bugs(Cimex spp.).Past research primarily focused on exploring the direct lethal effect of dusts against bed bugs,whereas information on their sublethal effects on bed bugs are limited.In this study,we evaluated the lethal effect of 3 dust products(Johnson's®Baby powder,Vazor DE powder^(TM),and CimeXaTM;abbreviated as Baby powder,DE,and TM CimeXa)against the tropical bed bug,Cimex hemipterus(F.),under laboratory conditions.Results showed that the 3 dust products caused 97%100%mortality to tropical bed bugs within 14 d,both in no-choice and choice experiments.However,in a brief exposure experiment(crossing a 2.5-cm-wide band),Baby powder exposure caused a significantly lower mortality(23%)than DE(88%)and CimeXa(100%).The more effective dusts(DE and CimeXa)were selected for further evaluation of their sublethal effects on C.hemipterus.DE and CimeXa caused significantly higher mortality(48%58%)through horizontal transfer than that of control(6%).Brief exposure to DE and CimeXa dusts did not affect tropical bed bug activity and their response to CO_(2).However,CimeXa-exposed tropical bed bugs exhibited reduced feeding and lowered survival rate after feeding.Moreover,both DE and CimeXa dust bands showed strong barrier effects on the crawling of tropical bed bugs.Our results indicate that both DE and CimeXa have great potential for preventing C.hemipterus from reaching protected areas and for controlling C.hemipterus.
