Introduction: Vector surveillance in high-rise buildings is important to predict and monitor the presence of vectors regarding their abundance and distribution. In this study, the infestation profile of Aedes aegypti and Aedes albopic- tus species in different environmental settings were investigated. Methods: Four high-rise apartments in four differ- ent localities were selected for ovitrap surveillance. Fifty ovitraps were placed in semi indoor and outdoor settings. Results: A total of 507 (42.8%) from ovitraps showed the presence of the Aedes species larvae. Out of these, 170 (33.5%) of the positive ovitraps were those placed in semi indoor and 337 (66.5%) in outdoor. Of the total 16,613 Aedes larvae found, 4,130 (24.9%) were from semi indoor, and 12,483 (75.1%) from outdoor. In terms of distri- bution, Ae. albopictus was predominantly found in outdoor environments (POI=87.5%; MLT=36.45 larvae). Ae. aegypti was also found in outdoor environments (POI=14.89%; MLT=8.26 larvae). There was a significant difference in POI for both Ae. aegypti and Ae. albopictus in the two different environments but no significant difference was observed in MLT, indicating that the density of the Aedes species in both environments was well distributed. Con- clusion: In this study, the patterns of Aedes habitat in high-rise apartments were observed. This study has shown an invasion and adaptation of Aedes mosquitoes into the ecosystems of high-rise buildings. It can be concluded that housing designs and the condition of the surrounding environment affects the infestation profile and the distribution of Aedes mosquitoes.
Introduction: The survivorship of mosquito is the most important aspect that affects its ability as a pathogen trans- mitting vector such as Aedes albopictus which is a vector of dengue. In this study, temperature stress effect on the survival of adult Aedes albopictus were investigated. Methods: It was conducted by manipulating different constant temperatures (15°C to 35°C) on juvenile stage of Ae. albopictus in natural and artificial container. Then, the devel- opment growth of adult mosquito was observed under laboratory condition. The effects of exposed temperature on certain biological parameters of adult mosquito were evaluated in terms of survival rates, longevity of female mosquito, fecundity rate, gonotrophic cycle and wing length of the adult mosquito. Results: In higher temperatures, the longevity of adult female was reduced and the highest longevity was found at optimum temperature (25°C) with average of 8.6 ± 0.18 days and 6.7 ± 0.29 days in natural and artificial container respectively. Both sexes showed a clearly tendency towards decreasing survivorship with increasing temperature where the highest survival was found at 15°C. Conversely, survival was lowest at a high temperature (30°C to 35°C). This study also showed that the wing length of both sexes was significantly affected by the rearing temperature where the longest found at 15°C and the shortest at 35°C. Conclusion: Thus, this study provide useful information of mosquito ecology in response to varia- tion of temperatures.
Introduction: The purpose of this research is to evaluate the effects of artificial light exposures on the survivals and life traits of adult Aedes aegypti. Methods: This is an experimental research where triplication of each cage filled with a ratio of 20 male : 20 female mosquitoes were exposed under three different light artificial light which are; yellow light, white light and blue light along with three different photoperiod regimes (light:dark) – (14h:10h, 12h:12h and 8h:16h). During this study, life traits data observed were duration of the females to complete a gonotrophic cycle, mean number of days was calculated as well as fecundity rate each cycle was also observed by calculating its number of eggs. Results: In general, gonotrophic cycle of this species is significantly affected by the exposure of the artificial lights where the white light has allowed this species to complete a gonotrophic cycle faster than yellow and blue light with post hoc Tukey’s HSD p = 0.026, however the gonotrophic cycle is found not affected by the different photoperiod regimes. The fecundity of this species is found not to be affected by the artificial light exposure but is affected by the different photoperiod regimes with p = 0.049. Conclusion: In conclusion, artificial light can signifi- cantly affect the gonotrophic cycle of Aedes aegypti species while on the other hand, the fecundity of this species is affected by the different photoperiod instead of different artificial light exposure.
Vector surveillance in high-rise buildings is important to predict and monitor the presence of vectors regarding their abundance and distribution. In this study, the infestation profile of Aedes aegypti and Aedes albopictus species in different environmental settings were investigated. Methods: Four high-rise apartments in four different localities were selected for ovitrap surveillance. Fifty ovitraps were placed in semi indoor and outdoor settings. Results: A total of 507 (42.8%) from ovitraps showed the presence of the Aedes species larvae. Out of these, 170 (33.5%) of the positive ovitraps were those placed in semi indoor and 337 (66.5%) in outdoor. Of the total 16,613 Aedes larvae found, 4,130 (24.9%) were from semi indoor, and 12,483 (75.1%) from outdoor. In terms of distribution, Ae. albopictus was predominantly found in outdoor environments (POI=87.5%; MLT=36.45 larvae). Ae. aegypti was also found in outdoor environments (POI=14.89%; MLT=8.26 larvae). There was a significant difference in POI for both Ae. aegypti and Ae. albopictus in the two different environments but no significant difference was observed in MLT, indicating that the density of the Aedes species in both environments was well distributed. Conclusion: In this study, the patterns of Aedes habitat in high-rise apartments were observed. This study has shown an invasion and adaptation of Aedes mosquitoes into the ecosystems of high-rise buildings. It can be concluded that housing designs and the condition of the surrounding environment affects the infestation profile and the distribution of Aedes mosquitoes.
Introduction: Aedes albopictus is known for its aggressiveness towards human and recently expanded to more coun- tries outside the native regions. Thus, the demographic parameters of Aedes albopictus are important to determine the characteristics of this species mosquitoes in terms of the reproduction rates and dispersal distance. Materials and Methods: This study, was performed using a Shah Alam strain of Aedes albopictus originally collected in twenty district areas of the central zone of Shah Alam. This research applies field work-study with a cross-sectional design to investigate the demographic parameters of Aedes albopictus. The demographic evaluation of Aedes albopictus was conducted under the control environment in insectarium. Results: Investigation on the demographic parameters of Aedes albopictus clearly showed that there is a significance different observed in the total number of mosquito eggs produced in both high and low incidence rate IR areas (p=0.03). In contrast, other parameters showed insignificant value between high and low IR areas. Conclusion: The key to control the mosquito vectors population is by tracking the vector’s life cycle including its survival. Therefore, the outcome of this study may provide as a baseline to esti- mate the dengue outbreak in the current episystem.
Introduction: The trend of several mosquito-borne diseases in Malaysia has shown an increasing pattern over the past few years despite close monitoring and continuous control initiatives by public health authority. The objective of this study is to determine the spatial and temporal epidemiology of mosquito-borne disease in Terengganu from the year 2009 to 2018. Terengganu has been selected because it is geographically unique and experiences two monsoon seasons per year. Methods: Weekly surveillance data of mosquito-borne diseases which include dengue fever, malaria, filariasis, Japanese Encephalitis (JE) and chikungunya from 2009 to 2018 were collected from the Terengganu State Health Department. The variables included in the dataset mainly comprises of disease onset, di- agnosis, case category, area (district) and site of onset. The data has been monitored spatial and temporal in which to explore the distribution pattern of the disease. The annual average for each type of mosquito-borne disease was determined using time-series and is further analysed by using geographical information system (GIS) tools to form spatial statistical analysis. Results: Results indicate that the temporal distribution of the mosquito-borne disease in Terengganu increases slightly despite a fluctuating pattern from the year 2009 to 2018 and there are between each type of mosquito-borne disease. Spatial analysis showed different stratification between seasons as well as the areas that are more susceptible to each disease. Conclusion: The results obtained in this present study through spatial and temporal analysis revealed that mosquito-borne diseases show a dynamic pattern in distribution. It can be concluded that the occurrence of the diseases depends on the geographical area and the weather within the region. This study provides public health authorities with a comprehensive assessment that will be useful for surveillance and monitor- ing, as well as for predicting and managing mosquito-borne disease outbreaks effectively.
A study was conducted to identify the responses of Aedes albopictus to different diet regime towards the development of juvenile and adult mosquitoes. Fish pellet was selected as standard diet in order to study the effect of diet regime on the development of Ae. Albopictus. Four different diet regimes (1.0 mg, 0.6 mg, 1.0 mg an1.6 mg) were tested on 50 eggs of Ae. albopictus under laboratory conditions. Juvenile development until adult emergence was observed and recorded. Results indicated that the time taken to mature the mosquitoes was significantly affected by the diet regime. Furthermore, juvenile body size and adult wing size of Ae. albopictus were found to be greatly affected by diet regime exposed during juvenile stages. In summary, an increase of diet regime resulted in the decrease of developmental time and an increase in juvenile body size and adult wing size.
Introduction: An experimental study was conducted to determine the effects of synthetic chemical artificial toxic sugar bait (ATSB) on adult Aedes albopictus population in a controlled environment. The method uses an “attract and kill” concept and makes use of mosquito’s sugar-feeding behaviour. Formulations of ATSB consists of natural scents as an attractant, a sugar solution as a feeding stimulant and an oral toxin such as boric acid to eliminate mos- quito population. Methods: The experiment was conducted in two phases; (i) the first phase aimed to determine the optimum sucrose concentration (10%, 30%, 50% and 70%) that will elicit the highest biting and fecundity rates in female mosquitoes and (ii) the second phase aimed to identify the ATSB, optimum sucrose from phase one incorpo- rated with boric acid (0.1%,0.5% and 1%), that cause the highest mortality rates of adult female Aedes albopictus in a laboratory environment. Results: Seventy percent sucrose concentration was selected as the optimum sucrose concentration because the ingestion of the solution cause the highest biting and fecundity rates in mosquito compare to other sucrose concentrations. Meanwhile, 1% boric acid resulted in the highest mortality rate within two days of the experiment period. Conclusion: This study has identified the optimum sucrose concentration required to attract adult mosquitoes and highlighted the efficacy of 1% boric acid as an effective mosquito adulticide. The findings highlight the potential of ATSB as a valuable vector control method which could be further developed for future use.