Evaluations of Mosquito Age Grading Techniques Based on Morphological Changes

Hugo, R. L., Quick-Mile, S., Kay, B.H. and Ryan, P.A. (2008) Evaluations of Mosquito Age Grading Techniques Based on Morphological Changes. Journal of Medical Entomology, 45 3: 353-369. doi:10.1603/0022-2585(2008)45[353:EOMAGT]2.0.CO;2


Author Hugo, R. L.
Quick-Mile, S.
Kay, B.H.
Ryan, P.A.
Title Evaluations of Mosquito Age Grading Techniques Based on Morphological Changes
Journal name Journal of Medical Entomology   Check publisher's open access policy
ISSN 0022-2585
Publication date 2008-05
Sub-type Article (original research)
DOI 10.1603/0022-2585(2008)45[353:EOMAGT]2.0.CO;2
Open Access Status
Volume 45
Issue 3
Start page 353
End page 369
Total pages 17
Place of publication United States
Publisher Entomological Society of America
Collection year 2009
Language eng
Subject C1
960499 Control of Pests, Diseases and Exotic Species not elsewhere classified
060808 Invertebrate Biology
060599 Microbiology not elsewhere classified
Abstract Evaluations were made of the accuracy and practicality of mosquito age grading methods based on changes to mosquito morphology; including the Detinova ovarian tracheation, midgut meconium, Polovodova ovariole dilatation, ovarian injection, and daily growth line methods. Laboratory maintained Aedes vigilax (Skuse) and Culex annulirostris (Skuse) females of known chronological and physiological ages were used for these assessments. Application of the Detinova technique to laboratory reared Ae. vigilax females in a blinded trial enabled the successful identification of nulliparous and parous females in 83.7–89.8% of specimens. The success rate for identifying nulliparous females increased to 87.8–98.0% when observations of ovarian tracheation were combined with observations of the presence of midgut meconium. However, application of the Polovodova method only enabled 57.5% of nulliparous, 1-parous, 2-parous, and 3-parous Ae. vigilax females to be correctly classified, and ovarian injections were found to be unfeasible. Poor correlation was observed between the number of growth lines per phragma and the calendar age of laboratory reared Ae. vigilax females. In summary, morphological age grading methods that offer simple two-category predictions (ovarian tracheation and midgut meconium methods) were found to provide high-accuracy classifications, whereas methods that offer the separation of multiple age categories (ovariolar dilatation and growth line methods) were found to be extremely difficult and of low accuracy. The usefulness of the morphology-based methods is discussed in view of the availability of new mosquito age grading techniques based on cuticular hydrocarbon and gene transcription changes.
Formatted abstract
Evaluations were made of the accuracy and practicality of mosquito age grading methods based on changes to mosquito morphology; including the Detinova ovarian tracheation, midgut meconium, Polovodova ovariole dilatation, ovarian injection, and daily growth line methods. Laboratory maintained Aedes vigilax (Skuse) and Culex annulirostris (Skuse) females of known chronological and physiological ages were used for these assessments. Application of the Detinova technique to laboratory reared Ae. vigilax females in a blinded trial enabled the successful identification of nulliparous and parous females in 83.7–89.8% of specimens. The success rate for identifying nulliparous females increased to 87.8–98.0% when observations of ovarian tracheation were combined with observations of the presence of midgut meconium. However, application of the Polovodova method only enabled 57.5% of nulliparous, 1-parous, 2-parous, and 3-parous Ae. vigilax females to be correctly classified, and ovarian injections were found to be unfeasible. Poor correlation was observed between the number of growth lines per phragma and the calendar age of laboratory reared Ae. vigilax females. In summary, morphological age grading methods that offer simple two-category predictions (ovarian tracheation and midgut meconium methods) were found to provide high-accuracy classifications, whereas methods that offer the separation of multiple age categories (ovariolar dilatation and growth line methods) were found to be extremely difficult and of low accuracy. The usefulness of the morphology-based methods is discussed in view of the availability of new mosquito age grading techniques based on cuticular hydrocarbon and gene transcription changes.
Keyword mosquito age grading
ovary morphology
physiological age
Q-Index Code C1
Q-Index Status Confirmed Code

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2009 Higher Education Research Data Collection
School of Biological Sciences Publications
 
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Created: Mon, 02 Mar 2009, 17:35:51 EST by Gail Walter on behalf of School of Biological Sciences