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.Unusual developing sites of dengue vectors and potential epidemiological implications
Dieng Hamady ; Saifur GM Rahman ; Ahmad Hassan Abu ; Salmah Che MR ; Aziz Thbiani Al ; Satho Tomomitsu ; Miake Fumio ; Jaal Zairi ; Abubakar Sazaly ; Morales Enrique Ronald
Asian Pacific Journal of Tropical Biomedicine 2012;(3):228-232
Objective: To identify the unusual breeding sites of two dengue vectors, i.e. Aedes albopictus (Ae. albopictus) and Aedes aegypti (Ae. aegypti). Methods: During the second half of 2010, we performed an occasional survey in rural (Teluk Tempoyak) and urban (Gelugor) areas of Penang Island, Malaysia, to identify cryptic breeding sites. Results: In the rural area, we found heterogeneous immature stages of Ae. albopictus in the water bowl of an encaged bird. We also observed Ae. aegypti eggs deposited in the flush tank of a toilet in the urban area. Conclusions:It can be concluded that both breeding patterns can increase contact with hosts (humans and birds) and presumably population densities of Ae. albopictus and Ae. aegypti, thereby potentially boosting the risks for spread and transmission of arboviral diseases.
4.The biology and demographic parameters of Aedes albopictus in northern peninsular Malaysia.
H Nur AIDA ; Hamady DIENG ; Abu Hassan AHMAD ; Tomomitsu SATHO ; A T NURITA ; M R Che SALMAH ; Fumio MIAKE ; B NORASMAH
Asian Pacific Journal of Tropical Biomedicine 2011;1(6):472-477
OBJECTIVETo generate life table characteristics for the dengue vector Aedes albopictus (A. albopictus) under uncontrolled conditions, incorporating both the aquatic and the adult stages.
METHODSTen females derived from wild pupae were allowed to fully blood-feed on restrained mice. 774 eggs were hatched in seasoned water. F1 larvae were followed for development until their F2 counterparts emerged as adults. Some population parameters were monitored (F1) or estimated (F2).
RESULTSA. albopictus exhibited increased fecundity and egg hatch success. Immature development was quick. Immature survival was high, with lowest rate in the pupal stage. Adult emergence was about 81% and sex ratio was close to 1:1. Generational mortality (K) was about 28%. A high proportion of females completed a reproductive cycle and the obtained parity rate was predicted to lead to higher fecundity in the next generation.
CONCLUSIONSIt can be concluded that natural A. albopictus populations in Penang seem largely determined by quick development in combination with low immature loss and increased oviposition.
Aedes ; growth & development ; physiology ; Animals ; Female ; Insect Vectors ; Malaysia ; Male ; Mice ; Vital Statistics
5.Household survey of container-breeding mosquitoes and climatic factors influencing the prevalence of Aedes aegypti (Diptera: Culicidae) in Makkah City, Saudi Arabia.
Al Thabiany AZIZ ; Hamady DIENG ; Abu Hassan AHMAD ; Jazem A MAHYOUB ; Abdulhafis M TURKISTANI ; Hatabbi MESED ; Salah KOSHIKE ; Tomomitsu SATHO ; Mr Che SALMAH ; Hamdan AHMAD ; Wan Fatma ZUHARAH ; Ahmad Saad RAMLI ; Fumio MIAKE
Asian Pacific Journal of Tropical Biomedicine 2012;2(11):849-857
OBJECTIVETo investigate the prevalence of container breeding mosquitoes with emphasis on the seasonality and larval habitats of Aedes aegypti (Ae. aegypti) in Makkah City, adjoining an environmental monitoring and dengue incidence.
METHODSMonthly visits were performed between April 2008 and March 2009 to randomly selected houses. During each visit, mosquito larvae were collected from indoors and outdoors containers by either dipping or pipetting. Mosquitoes were morphologically identified. Data on temperature, relative humidity, rain/precipitations during the survey period was retrieved from governmental sources and analyzed.
RESULTSThe city was warmer in dry season (DS) than wet season (WS). No rain occurred at all during DS and even precipitations did fall, wetting events were much greater during WS. Larval survey revealed the co-breeding of Aedes, Culex and Anopheles in a variety of artificial containers in and around homes. 32 109 larvae representing 1st , 2nd, 3rd, and 4th stages were collected from 22 618 container habitats. Culicines was far the commonest and Aedes genus was as numerous as the Culex population. Ae. aegypti larval abundance exhibited marked temporal variations, overall, being usually more abundant during WS. Ten types of artificial containers were found with developing larvae. 70% of these habitats were located indoors. 71.42% of indoor containers were permanent and 28.58% was semi-permanent during WS. Cement tanks was the only container type permanent during DS. Ae. aegypti larval indices (CI, HI, BI) recorded were greater during WS.
CONCLUSIONSTaken together, these results indicate a high risk of dengue transmission in the holy city.
Aedes ; Animals ; Culicidae ; Dengue ; transmission ; Ecosystem ; Environmental Monitoring ; Larva ; Prevalence ; Saudi Arabia ; epidemiology ; Seasons ; Weather
6. 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
7. 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.