1.Laboratory efficacy of mycoparasitic fungi (Aspergillus tubingensis and Trichoderma harzianum) against tropical bed bugs (Cimex hemipterus) (Hemiptera: Cimicidae)
Zahran ZULAIKHA ; Dieng HAMADY ; Satho TOMOMITSU
Asian Pacific Journal of Tropical Biomedicine 2017;7(4):288-293
Objective:To test the effectiveness of conidial spore formulations [Aspergillus tubingensis (A.tubingensis) and Trichoderma harzianum (T.harzianum)] against tropical bed bugs,Clnex 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 ofA.tubingensis (LT50 =44.629 h) at the conidial exposure of 1 × 106 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 × 104 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.
2.Morphological and molecular characterization of fungus isolated from tropical bed bugs in Northern Peninsular Malaysia, Cimex hemipterus (Hemiptera:Cimicidae)
Zahran Zulaikha ; Ismail Azliza Nor ; Rahman Abdul Wardah ; Dieng Hamady ; Satho Tomomitsu
Asian Pacific Journal of Tropical Biomedicine 2015;(9):684-690
To investigate some morphological and molecular characteristics of fungal parasites isolated from wild tropical bed bug, Cimex hemipterus. Methods: A series of culture methods were used to obtain fungal isolates from field-collected bed bugs. Characteristics of the isolates such as colony appearance, mycelial texture and pigmentation were studied to explore their morphology. Isolates were also subjected to a PCR-based genotyping test. Results: There were noticeable differences in morphological characteristics among the four isolates. Conidial areas of one isolate were dark green, whereas those of the remaining colonies were olive-green, black or dark brown. Conidia of the dark green isolate were globose, while those of olive-green, black and dark brown isolates were globose to subglobose, globose to spherical and globose to subglobose/finely roughened, respectively. These morphological specificities and the molecular analyses showed that the fungal internal transcribed spacer ribosomal region and β-tubulin gene sequences of the isolates shared clade with Trichoderma and Aspergillus sequences. Conclusions: Overall, the new discovery of common pathogens in agricultural field developed in live bed bugs storage tank may initiate the use of biological agents in later years.
3. Laboratory efficacy of mycoparasitic fungi (Aspergillus tubingensis and Trichoderma harzianum) against tropical bed bugs (Cimex hemipterus) (Hemiptera: Cimicidae)
Zulaikha ZAHRAN ; Abdul Hafiz AB MAJID ; Nik Mohd Izham MOHAMED NOR ; Hamady DIENG ; Tomomitsu SATHO
Asian Pacific Journal of Tropical Biomedicine 2017;7(4):288-293
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
4. Morphological and molecular characterization of fungus isolated from tropical bed bugs in Northern Peninsular Malaysia, Cimex hemipterus (Hemiptera: Cimicidae)
Abdul Hafiz AB MAJID ; Zulaikha ZAHRAN ; Abd Hafis ABD RAHIM ; Nor Azliza ISMAIL ; Wardah ABDUL RAHMAN ; Kartiekasari Syahidda MOHAMMAD ZUBAIRI ; Hamady DIENG ; Tomomitsu SATHO
Asian Pacific Journal of Tropical Biomedicine 2015;5(9):707-713
Objective: To investigate some morphological and molecular characteristics of fungal parasites isolated from wild tropical bed bug, Cimex hemipterus. Methods: A series of culture methods were used to obtain fungal isolates from field-collected bed bugs. Characteristics of the isolates such as colony appearance, mycelial texture and pigmentation were studied to explore their morphology. Isolates were also subjected to a PCR-based genotyping test. Results: There were noticeable differences in morphological characteristics among the four isolates. Conidial areas of one isolate were dark green, whereas those of the remaining colonies were olive-green, black or dark brown. Conidia of the dark green isolate were globose, while those of olive-green, black and dark brown isolates were globose to subglobose, globose to spherical and globose to subglobose/finely roughened, respectively. These morphological specificities and the molecular analyses showed that the fungal internal transcribed spacer ribosomal region and β-tubulin gene sequences of the isolates shared clade with Trichoderma and Aspergillus sequences. Conclusions: Overall, the new discovery of common pathogens in agricultural field developed in live bed bugs storage tank may initiate the use of biological agents in later years.