What does not kill it does not always make it stronger: High temperatures in pyriproxyfen treatments produce Aedes aegypti adults with reduced longevity and smaller females

Author(s)

Moura, Lidia ^[1] ; de Nadai, Barbara Lepretti ^{[1, 2]} ; Corbi, Juliano J. ^[2]

Affiliation

^[1] Univ Sao Paulo, Sao Carlos Sch Engn, Dept Hydraul & Sanitat, Lab Aquat Ecol, BR-13563120 Sao Carlos, SP - Brazil

^[2] Corbi, Juliano J., Univ Sao Paulo, Sao Carlos Sch Engn, Dept Hydraul \& Sanitat, Lab Aquat Ecol, BR-13563120 Sao Carlos, SP, Brazil.Moura, Lidia, Univ Sao Paulo, Sao Carlos Sch Engn, Dept Hydraul & Sanitat, Lab Aquat Ecol, BR-13563120 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF ASIA-PACIFIC ENTOMOLOGY; v. 23, n. 2, p. 529-535, JUN 2020.
• Web of Science Citations: 3

Abstract

Aedes aegypti control in Brazil comprises integrated actions, in which larvicide application is a supplementary measure. Despite the importance of analyzing the effects of temperature on the efficiency of larvicides to control mosquito populations, there is still a lack of information regarding the sublethal effect of larvicides. We hypothesized that mosquitoes which survived pyriproxyfen exposure, during their immature development, have small body sizes and live less than mosquitoes that were not exposed to this larvicide. We investigated the sublethal effects of five different pyriproxyfen concentrations (0.0001; 0.001; 0.01; 0.1 and 1 mg.L-1), under three different temperatures (20, 25 and 30 degrees C). As we increased the larvicide concentration, less larvae survived and developed into adults. However, at 30 degrees C the survival was higher than at 25 degrees C and 20 degrees C comparing the concentrations of 0.001 mg.L-1 and 0.01 mg.L-1 (10% and 16% high, respectively). Mosquito survivors to pyriproxyfen exposure, in all thermal conditions, had shorter adult life spans than mosquitoes not exposed to pyriproxyfen during the larval stage. The females exposed at 30 degrees C showed smaller wings than females from experiments at 20 degrees C. These findings provide evidence that the biological parameters of the adult lifespan and wing centroid size are impaired due to larval exposure to pyriproxyfen, even at high temperatures. Reduced longevity and small wing size are fitness costs to survive this larvicide exposure. These findings provide support to assess resistance development to larvicides through future generations and contribute to the discussion on improving the rational application of larvicides. (AU)

• FAPESP's process: 16/24622-9 - Study of mosquito Aedes aegypti frequency wings beat using intelligent sensors: simulation of different environmental conditions in laboratory
• Grantee: Barbara Lepretti de Nadai
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 16/04986-6 - Intelligent traps and sensors: an innovative approach to control insect pests and disease vectors
• Grantee: Gustavo Enrique de Almeida Prado Alves Batista
• Support Opportunities: Research Grants - eScience and Data Science Program - Regular Program Grants