Synergistic larvicidal effects of temephos and Bacillus thuringiensis israelensis against Aedes albopictus: a laboratory and field study
- 1Zhejiang Provincial Center for Disease Control and Prevention , , ,
- 2Shaoxing Center for Disease Control and Prevention , , ,
- 3Keqiao District Center for Disease Control and Prevention , , ,
Abstract
Background: Aedes mosquito-borne diseases, such as dengue fever, pose significant challenges to global public health. Mosquito management is regarded as one of the most critical measures to control these diseases. Temephos has been widely used for larval mosquito control, but its sustained application has resulted in the emergence of resistance in many regions in China. Bacillus thuringiensis israelensis (Bti) offers an environmentally friendly alternative, but its field efficacy against late-instar larvae is limited. Previous studies have demonstrated the synergistic potential of combining temephos and Bti. Therefore, this study aims to determine the most effective combination ratio through laboratory bioassays and to evaluate the practical efficacy of this mixed formulation under field conditions.
Methods: Laboratory bioassays were conducted with early fourth-instar Aedes albopictus (Skuse, 1894) larvae to determine the co-toxicity coefficient (CTC) of 3 mixed formulations (temephos: Bti = 1:1, 1:3, and 1:5). In field trials, the mixed formulation with the greatest synergistic effect was used to evaluate its insecticidal effect under field conditions. A total of 150 natural breeding containers in one village in Shaoxing City were randomly selected and assigned to 3 groups (treatment group A, treatment group B, and the control group). Two application regimens (half-monthly application at twice the 99% lethal concentration [2 × LC99] vs. monthly application at 4 × LC99) were used in the treatment groups, and larval densities were monitored over a 3-month period to assess their larvicidal effects.
Results: The CTC values for all three mixed formulations were 141.477, 140.299, and 150.009, respectively (all exceeding 120), and mixed formulation C (temephos: Bti = 1:5) was selected for field trials. Over the 3-month period, the standard rates of reduction in mosquito larval density were 100.00%, 100.00%, and 100.00% in group A, while group B showed reductions of 96.80%, 87.03%, and 96.79%. Both treatment groups exhibited significantly lower larval densities than the control group (p < 0.001), while no statistically significant difference was found between them.
Conclusion: The combination of temephos and Bti showed a synergistic effect under laboratory conditions, and the mixed formulation demonstrated effective larvicidal activity under field conditions.
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BibTeX
@article{wu2026synergistic,
title = {{Synergistic larvicidal effects of temephos and Bacillus thuringiensis israelensis against Aedes albopictus: a laboratory and field study}},
author = {Yuyan Wu and Qinmei Liu and Jimin Sun and Yifang Hong and Ying Fu and Dianying Zhou and Feng Ling and Guoqin Jiang},
journal = {Frontiers in veterinary science},
year = {2026},
month = oct,
doi = {10.3389/fvets.2026.1930489},
url = {https://europepmc.org/article/PMC/PMC13727618},
note = {CC BY},
}
RIS
TY - JOUR
TI - Synergistic larvicidal effects of temephos and Bacillus thuringiensis israelensis against Aedes albopictus: a laboratory and field study
AU - Yuyan Wu
AU - Qinmei Liu
AU - Jimin Sun
AU - Yifang Hong
AU - Ying Fu
AU - Dianying Zhou
AU - Feng Ling
AU - Guoqin Jiang
PY - 2026
DA - 2026/10/20
JO - Frontiers in veterinary science
DO - 10.3389/fvets.2026.1930489
UR - https://europepmc.org/article/PMC/PMC13727618
AB - Background: Aedes mosquito-borne diseases, such as dengue fever, pose significant challenges to global public health. Mosquito management is regarded as one of the most critical measures to control these diseases. Temephos has been widely used for larval mosquito control, but its sustained application has resulted in the emergence of resistance in many regions in China. Bacillus thuringiensis israelensis (Bti) offers an environmentally friendly alternative, but its field efficacy against late-instar larvae is limited. Previous studies have demonstrated the synergistic potential of combining temephos and Bti. Therefore, this study aims to determine the most effective combination ratio through laboratory bioassays and to evaluate the practical efficacy of this mixed formulation under field conditions. Methods: Laboratory bioassays were conducted with early fourth-instar Aedes albopictus (Skuse, 1894) larvae to determine the co-toxicity coefficient (CTC) of 3 mixed formulations (temephos: Bti = 1:1, 1:3, and 1:5). In field trials, the mixed formulation with the greatest synergistic effect was used to evaluate its insecticidal effect under field conditions. A total of 150 natural breeding containers in one village in Shaoxing City were randomly selected and assigned to 3 groups (treatment group A, treatment group B, and the control group). Two application regimens (half-monthly application at twice the 99% lethal concentration [2 × LC99] vs. monthly application at 4 × LC99) were used in the treatment groups, and larval densities were monitored over a 3-month period to assess their larvicidal effects. Results: The CTC values for all three mixed formulations were 141.477, 140.299, and 150.009, respectively (all exceeding 120), and mixed formulation C (temephos: Bti = 1:5) was selected for field trials. Over the 3-month period, the standard rates of reduction in mosquito larval density were 100.00%, 100.00%, and 100.00% in group A, while group B showed reductions of 96.80%, 87.03%, and 96.79%. Both treatment groups exhibited significantly lower larval densities than the control group (p < 0.001), while no statistically significant difference was found between them. Conclusion: The combination of temephos and Bti showed a synergistic effect under laboratory conditions, and the mixed formulation demonstrated effective larvicidal activity under field conditions.
SN - 2297-1769
ER -