ISCEP 2026 At Sunway Putra Hotel 17-18 August 2026
ABSTRACT
COMPARISON OF THE RESIDUAL EFFICACY OF LAMBDA CYHALOTHRIN CAPSULE SUSPENSION AGAINST Aedes AEGYPTI BETWEEN TWO SPRAY CYCLES
P29
Aimi Afiqah MOHAMMADIN, Norlaili MISRAWI, Fatin Nur Adlina ROZAIDI, Ezita Qaisara RIDZUAN, Mohammad Farizul MOHAMMAD FATIHI, Haziq Uzair MOHD ROSLI, Afiq Asyraf MOHD FAIZOL, Farah Diana ARIFFIN, Nurulhusna AB HAMID*
Medical Entomology Unit Infectious Diseasearch Canha, Institute for Medical Research, Nationa of Health, Ministry of Health, Selangor, Malaysia usne [email protected]
ABSTRACT
The residual performance of insecticides is a key determinant of their effectiveness in vector control programmes, particularly for managing Aedes aegypti, the primary vector of dengue transmission. This study evaluated the residual bio-efficacy of a capsule suspension formulation against laboratory strain (LS) and wild strain (WS) Aedes aegypti under semi-field conditions using the standard WHO cone bioassay Adult mosquitoes were exposed to treated surfaces at three domestic resting heights (40 cm 80 cm, and 120 cm), and knockdown and 24-hour mortality responses were monitored across two application cycles over an extended period. The results demonstrated marked strain-dependent variation in residual efficacy. For the laboratory strain, the capsule suspension maintained high residual efficacy across bath cycles, reaching a peak mortality of 37.55 ± 2.05% by Day 42 in Cycle 1 and sustaining 100% average mortality through Day 70 in Cycle 2. with residual performance remaining above 68% up to Day 140 (68.52 ± 5.86%). In contrast, the wild strain exhibited substantially lower and less predictable susceptibility in Cycle 1, wild strain mortality remained low (1.23% ±214% on Day 28 to 11.60 ± 2.37% on Day 70] across most intervals despite a transient peak at Day 42 (98.89 ± 1.92%), while Cycle 2 showed a gradual increase in mortality peaking at Day 56 (28.9 ± 175%) before declining to 3410 ± 8.08% by Day 140. Efficacy trends were generally comparable across the evaluated resting heights without significant height-dependent variations. These findings indicate that while the capsule suspension provides extended residual control against susceptible laboratory populations, wild populations display high variability and reduced susceptibility under semi-field conditions, highlighting the essential need to evaluate vector control formulations against local wild strains when assessing residual spray efficacy
Keywords: capul suspension, Aedes aegypt, cone bioassay maidual longevity, insecticide resistance, vector control
INTERNATIONAL SCIENTIFIC CONFERENCE ON ENTOMOLOGY AND PEST SCP) 2005