ABSTRACT
Objective: To determine abundance, distribution and diversity of potential breeding container habitats of the dengue vectors in public places including schools, restaurants, mosques and parks in southwest areas of Penang Island, Malaysia. Methods: Premises at restaurants, schools, parks and mosques were surveyed simulta-neously and inspected visually for container habitats and production of immature mosquitoes from March 2015 to March 2016. Abundance (mean ± SE) of breeding containers between sites was compared using One-way ANOVA. Independent sample t-test was used to compare total number of Aedes albopictus (Ae. albopictus) and Aedes aegypti (Ae. aegypti) surveyed. Results: The surveyed locations yielded a total of 3741 breeding containers and 19537 immature mosquitoes from four areas. Concurrent artificial and natural containers pro-duced 78.4%immature Ae. albopictus and 6.3%Ae. aegypti mosquitoes in wet season, with 14.2% Ae. albopictus and 1.1% Ae. aegypti mosquitoes in dry season. Artificial containers accounted for 98.1% of the total containers recorded, with restaurants being the most productive locations (8012) and schools being the least productive (2234). Conclusions: It was concluded that public places are good sources of potential container habitats of Aedes mosquitoes in Penang Island, Malaysia and Ae. albopictus has exclu-sively replaced the home-grown Ae. aegypti even in urban areas. Therefore, treatment of artificial containers in such locations is critical in Aedes mosquito control campaigns during dengue outbreaks.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.