Back to the future: quantifying wing wear as a method to measure mosquito age
File(s)
Author(s)
Type
Journal Article
Abstract
Vector biologists have long sought the ability to accurately quantify the age of wild mosquito populations, a metric used to measure vector control efficiency. This has proven challenging due to the difficulties of working in the field and the biological complexities of wild mosquitoes. Ideal age grading techniques must overcome both challenges while also providing epidemiologically relevant age measurements. Given these requirements, the Detinova parity technique, which estimates age from the mosquito ovary and tracheole skein morphology, has been most often used for mosquito age grading despite significant limitations, including being based solely on the physiology of ovarian development. Here, we have developed a modernized version of the original mosquito aging method that evaluated wing wear, expanding it to estimate mosquito chronological age from wing scale loss. We conducted laboratory experiments using adult Anopheles gambiae held in insectary cages or mesocosms, the latter of which also featured ivermectin bloodmeal treatments to change the population age structure. Mosquitoes were age graded by parity assessments and both human- and computational-based wing evaluations. Although the Detinova technique was not able to detect differences in age population structure between treated and control mesocosms, significant differences were apparent using the wing scale technique. Analysis of wing images using averaged left- and right-wing pixel intensity scores predicted mosquito age at high accuracy (overall test accuracy: 83.4%, average training accuracy: 89.7%). This suggests that this technique could be an accurate and practical tool for mosquito age grading though further evaluation in wild mosquito populations is required.
Date Issued
2022-09-01
Date Acceptance
2022-04-15
Citation
American Journal of Tropical Medicine and Hygiene, 2022, 107 (3), pp.689-700
ISSN
0002-9637
Publisher
American Society of Tropical Medicine and Hygiene
Start Page
689
End Page
700
Journal / Book Title
American Journal of Tropical Medicine and Hygiene
Volume
107
Issue
3
Copyright Statement
Copyright © 2022 The American Society of Tropical Medicine and Hygiene.
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/35895347
PII: tpmd211173
Subjects
AEDES-AEGYPTI DIPTERA
ANOPHELES-GAMBIAE
CULICIDAE
GROWTH
IVERMECTIN
LEVEL
Life Sciences & Biomedicine
MALARIA VECTOR
OVARIAN DEVELOPMENT
Public, Environmental & Occupational Health
Science & Technology
SURVIVAL
TRANSMISSION
Tropical Medicine
Publication Status
Published
Coverage Spatial
United States
Date Publish Online
2022-07-18