Ovitrap surveillance was initiated for eight continuous weeks to determine the distribution and abundance of Aedes sp. mosquitoes in the University of Malaya campus, Kuala Lumpur, and the impact of meteorological conditions on the Aedes populations. Two study areas within the campus were selected: Varsity Lake and Seventh Residential College. The abundance of Aedes populations in Varsity Lake was indicated by ovitrap index (OI) which ranged from 60.00% - 90.00%. The mean number of larvae per ovitrap of Aedes albopictus in Varsity Lake ranged from 11.23 +/- 2.42 - 43.80 +/- 6.22. On the other hand, the outdoor OI for Seventh Residential College ranged from 73.33% - 93.33%, respectively, while the mean number larvae per ovitrap for this area ranged from 19.33 +/- 4.55 - 35.27 +/- 5.46, respectively. In addition, the indoor OI of Seventh Residential College ranged from 0.00% - 30.00%, while the mean number of larvae per ovitrap for Ae. albopictus ranged from 0 - 5.90 +/- 3.55. There was no significant difference (p > 0.05) of Ae. albopictus population between Varsity Lake and Seventh Residential College. The studies showed a correlation between OI and mean number of larvae per ovitrap for outdoor Ae. albopictus populations in Varsity Lake and Seventh Residential College (r = 0.794). There was also a correlation between the mean larvae number per ovitrap of Ae. albopictus obtained from eight weeks indoor ovitrap surveillance in Seventh Residential College with rainfall (r = 0.584). However, there was no correlation between the mean larvae number per ovitrap of Ae. albopictus in both study areas with temperature and relative humidity. Aedes aegypti mosquitoes were found neither indoor nor outdoor in both study areas. This study indicated that the principal dengue vector in the university campus was most likely Ae. albopictus.
College ; Seventh ; Lake ; Aedes ; seconds

Human-landing catch (HLC) technique was undertaken in nine selected study sites within Peninsular Malaysia to determine the biting cycle of Aedes, Armigeres, Culex, and Mansonia mosquitoes. HLC was conducted 24 hours on three different nights in a duration of one week at each study site. Aedes albopictus were found in all study sites with bimodal biting cycle, whereas the biting peak of Aedes butleri was recorded between 1600 and 1900 hr. For Armigeres, five study sites demonstrated similar biting peak hour (1900 – 2000 hr) for Ar. kesseli four study sites showed biting peak at 1800 – 1900 hr for Ar. subalbatus. Culex quinquefasciatus was collected from all study sites except in Sungai Penchala with its biting activity beginning from 1900 hr. Both Mansonia annulifera and Mansonia uniformis captured in two different study sites showed similar biting peaks (1500 – 1600 hr). It is recommended that vector control activities be carried out at dusk as almost all mosquito species captured started their biting activities at that time.

The susceptibility levels of Malaysian Aedes albopictus larvae sampled from several agricultural, fogging-free residential and dengue prone residential areas against different larvicides were evaluated using revised diagnostic doses derived from the 2xLC99 values of the reference strain. Upon 24-hour recovery period of WHO larval bioassay, incipient resistance was observed among Ae. albopictus larvae from rubber estates against fenitrothion (96.67% mortality) and permethin (97.00% mortality) while Ae. albopictus larvae from rice cultivation areas were moderately resistant to fenthion (94.33% mortality). Aedes albopictus larvae from dengue prone residential areas developed moderate to high resistance against dichlorodiphenyltrichloroethane (DDT), fenitrothion, fenthion, propoxur and permethrin (79.67% – 97.33% mortality). Moderate to high resistance were also demonstrated among all populations of Ae. albopictus larvae against temephos and chlorpyrifos (63.00% – 97.67% mortality). Except for Ae. albopictus larvae from oil palm plantations, all Ae. albopictus larval populations were also highly resistant to bendiocarb (65.67% – 89.67% mortality). Cross resistance between larvicides from similar and different insecticide classes were also revealed in this study. The use of revised diagnostic doses established from the local reference strain could reduce the possibility of underestimation or overestimation of the insecticide susceptibility status of field strain populations.

Ovitrap surveillance was carried out in fifteen localities encompassing foggingfree and dengue risk areas in West Malaysia to determine on the dispersal and prevalence of single and co-breeding of mosquito larvae particularly Aedes. Ovitraps were sited randomly indoors and outdoors within human settlements in all study areas. All the localities exhibited positive ovitraps with single breeding of Ae. albopictus that ranged between 64.29% and 100.00%. These findings indicated Ae. albopictus as the predominant container-breeding species in all study areas. The co-breeding of Ae. aegypti with Ae. albopictus larvae (34 ovitraps), Ae. albopictus with Culex quinquefasciatus larvae (32 ovitraps) as well as Cx. quinquefasciatus with Armigeres subalbatus larvae (1 ovitrap) were also detected in certain study localities. Interestingly, co-breeding of Ae. albopictus with Ar. subalbatus larvae as well as Ae. albopictus with Uranotaenia sp. larvae in Malaysia is reported for the first time in the present study. Better understanding of the co-breeding scenario involving different species of mosquito larvae is needed to ensure the efficacy of vector control actions to be conducted.