1.Assessment of the susceptibility status of Aedes albopictus (Diptera: Culicidae) from Interior, Sandakan and Tawau divisions of Sabah, Malaysia based on WHO diagnostic doses of larvicides
Elia-Amira, N.M.R. ; Chen, C.D. ; Low, V.L. ; Lau, K.W. ; Haziqah-Rashid, A. ; Amelia-Yap, Z.H. ; Lee, H.L. ; Azidah, A.A. ; Sofian-Azirun, M.
Tropical Biomedicine 2021;38(No.2):196-204
Susceptibility status of Aedes albopictus (Skuse) sampled from residential areas in Interior, Sandakan and Tawau divisions of Sabah, Malaysia, was evaluated based on the WHOrecommended doses of organochlorine and organophosphate larvicides. To determine susceptibility status, larval bioassays were carried out and post 24-hour mortalities based on WHO resistance classifications were adopted. The results demonstrated that Ae. albopictus larvae were resistant toward 5 out of the 8 larvicides tested. Larvae from all populations were resistant against bromophos, fenitrothion, malathion, temephos and dichlorodiphenyltrichloroethane (DDT), with mortalities ranging from 0.00 to 89.33%. Dieldrin, on the other hand, could induce 100.00% mortalities in all populations, followed by fenthion and chlorpyrifos, with mortalities ranging from 97.33 to 100.00% and 81.33 to 100.00% respectively. Despite most populations exhibiting similitude in their resistance status, larvae from Sandakan exhibited the highest resistance level whereas the lowest level was observed in Keningau. In view of the inadequacy of some larvicides in controlling Ae. albopictus in this study, integrated management such as insecticide rotation or combination of interventions is warranted.
2.Preliminary dengue vector surveillance in the Sunda Islands, Indonesia: Interchange of breeding habitat preferences of Aedes aegypti and Aedes albopictus
Haziqah-Rashid, A. ; Chen, C.D. ; Lau, K.W. ; Low, V.L. ; Sofian-Azirun, M. ; Halim, M.R.A. ; Suana, I.W ; Harmonis ; Syahputra, E. ; Razak, A. ; Chin, A.C. ; Azidah, A.A.
Tropical Biomedicine 2019;36(1):60-69
Ovitrap surveillance was conducted to determine the infestation patterns of dengue
vectors in fourteen study sites across eight provinces located in the Sunda Islands, Indonesia.
High ovitrap indices up to 70% and 90% were obtained from indoor and outdoor areas,
respectively. Mean numbers of Ae. aegypti and Ae. albopictus larvae ranged from 0.13 to
14.50 and 0.10 to 18.60, respectively. Mixed infestation (<10%) and interchange of breeding
habitat preferences of Ae. albopictus and Ae. aegypti were also observed in the present study.