Laboratory testing of low concentration (<1 ppm) of copper to prolong mosquito pupation and adult emergence time: An alternative method to delay mosquito life cycle.

Publisher: Public Library of Science Country of Publication: United States NLM ID: 101285081 Publication Model: eCollection Cited Medium: Internet ISSN: 1932-6203 (Electronic) Linking ISSN: 19326203 NLM ISO Abbreviation: PLoS One Subsets: MEDLINE

Original Publication: San Francisco, CA : Public Library of Science

Copper/*pharmacology ; Insecticides/*pharmacology ; Larva/*drug effects ; Mosquito Control/*methods ; Mosquito Vectors/*drug effects; Aedes/drug effects ; Animals ; Anopheles/drug effects ; Culex/drug effects

Introduction: Larvicide application in ovitrap is one of the currently available methods used in mosquito eradication campaign. We previously reported that copper in liquid form is a promising candidate due to its potent larvicide properties in a laboratory setting and in the field. In the field study, several larvae survived in outdoor ovitrap due to the dilution of copper concentration by rainwater. The surviving larvae were smaller and less motile. This led our interest to study the effect of a sub-lethal dose of copper in ovitrap on mosquito larval development, pupation time and lifespan in the adult stage.
Methods: First instar larvae of Aedes albopictus, Anopheles stephensi, and Culex pipiens were put in water containing 0.15 ppm, 0.30 ppm, and 0.60 ppm of copper. The surviving larvae, the emerging pupae, and adult mosquitoes were observed and counted every 24-hour and statistically analyzed by t-test or Mann-Whitney U test. Inter-species difference in response to different concentration of copper were also analyzed.
Results: Copper showed a potent larvicide effect at 0.60 ppm concentration. Prolonged pupation time and a lower number of adult mosquitoes were observed at 0.15 ppm concentration. Copper exposure did not affect adult mosquitoes' lifespan. Culex pipiens was the most susceptible species to copper exposure.
Conclusion: This study demonstrates the efficacy of copper at <1 ppm to kill mosquito larvae and to prolong pupation and adult emergence time. Utilization of copper at a low concentration is cost-efficient in the public health setting and remains an open option as an environmentally safe vector control strategy.
Competing Interests: The authors have declared that no competing interests exist.

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0 (Insecticides)
789U1901C5 (Copper)

Date Created: 20200522 Date Completed: 20200909 Latest Revision: 20200909

20240829

PMC7241823

10.1371/journal.pone.0226859

32437348