Technical note: A rapid, non-invasive method for measuring live or preserved insect specimens using digital image analysis
The measurement of insects is an important component of many entomological applications, including forensic evidence, where larvae size is used as a proxy for developmental stage, and hence time since colonization/death. Current methods for measuring insects are confounded by varying preservation te...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2019-01-01
|
| Series: | Forensic Science International: Synergy |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2589871X19301366 |
| _version_ | 1811221755704901632 |
|---|---|
| author | Donald R. Bourne Christopher J. Kyle Helene N. LeBlanc David Beresford |
| author_facet | Donald R. Bourne Christopher J. Kyle Helene N. LeBlanc David Beresford |
| author_sort | Donald R. Bourne |
| collection | DOAJ |
| description | The measurement of insects is an important component of many entomological applications, including forensic evidence, where larvae size is used as a proxy for developmental stage, and hence time since colonization/death. Current methods for measuring insects are confounded by varying preservation techniques, biased and non-standardized measurements, and often a lack of sample size given practical constraints. Towards enhanced accuracy and precision in measuring live insects to help avoid these variables, and that allows for different measurements to be analyzed, we developed a non-invasive, digital method using widely available free analytical software to measure live blow fly larvae. Using crime scene photographic equipment currently standard in investigation protocols, we measured the live length of 282 Phormia regina larvae. Repeated measurements of maggots, for all instars, were performed for several orientations and images. Most accurate measurements were obtained when maggots were oriented in their natural full extension. Killed specimens resulted in greater length measurements (Mean 1.79 ± 1.11 mm) when compared to live length. Herein, we report a technically simple, fast, and accurate measurement technique adapted for field and lab-based measurements, as well as, a simple linear equation for conversion of live length to standard killed length measurements. We propose this method be utilized for the standardization of forensic entomological evidence collection and development model creation. Keywords: Forensic entomology, Digital image measurement, Morphometric, Insect size, Phormia regina, Forensic photography |
| first_indexed | 2024-04-12T08:05:54Z |
| format | Article |
| id | doaj.art-9d409846ea9743e4bb09367d040281eb |
| institution | Directory Open Access Journal |
| issn | 2589-871X |
| language | English |
| last_indexed | 2024-04-12T08:05:54Z |
| publishDate | 2019-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Forensic Science International: Synergy |
| spelling | doaj.art-9d409846ea9743e4bb09367d040281eb2022-12-22T03:41:10ZengElsevierForensic Science International: Synergy2589-871X2019-01-011140145Technical note: A rapid, non-invasive method for measuring live or preserved insect specimens using digital image analysisDonald R. Bourne0Christopher J. Kyle1Helene N. LeBlanc2David Beresford3Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, CanadaEnvironmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada; Forensic Science Department, Trent University, Peterborough, Ontario, Canada; Corresponding author. Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada.Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada; Faculty of Science - Forensic Science, University of Ontario Institute of Technology, Oshawa, Ontario, CanadaEnvironmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada; Biology Department, Trent University, Peterborough, Ontario, CanadaThe measurement of insects is an important component of many entomological applications, including forensic evidence, where larvae size is used as a proxy for developmental stage, and hence time since colonization/death. Current methods for measuring insects are confounded by varying preservation techniques, biased and non-standardized measurements, and often a lack of sample size given practical constraints. Towards enhanced accuracy and precision in measuring live insects to help avoid these variables, and that allows for different measurements to be analyzed, we developed a non-invasive, digital method using widely available free analytical software to measure live blow fly larvae. Using crime scene photographic equipment currently standard in investigation protocols, we measured the live length of 282 Phormia regina larvae. Repeated measurements of maggots, for all instars, were performed for several orientations and images. Most accurate measurements were obtained when maggots were oriented in their natural full extension. Killed specimens resulted in greater length measurements (Mean 1.79 ± 1.11 mm) when compared to live length. Herein, we report a technically simple, fast, and accurate measurement technique adapted for field and lab-based measurements, as well as, a simple linear equation for conversion of live length to standard killed length measurements. We propose this method be utilized for the standardization of forensic entomological evidence collection and development model creation. Keywords: Forensic entomology, Digital image measurement, Morphometric, Insect size, Phormia regina, Forensic photographyhttp://www.sciencedirect.com/science/article/pii/S2589871X19301366 |
| spellingShingle | Donald R. Bourne Christopher J. Kyle Helene N. LeBlanc David Beresford Technical note: A rapid, non-invasive method for measuring live or preserved insect specimens using digital image analysis Forensic Science International: Synergy |
| title | Technical note: A rapid, non-invasive method for measuring live or preserved insect specimens using digital image analysis |
| title_full | Technical note: A rapid, non-invasive method for measuring live or preserved insect specimens using digital image analysis |
| title_fullStr | Technical note: A rapid, non-invasive method for measuring live or preserved insect specimens using digital image analysis |
| title_full_unstemmed | Technical note: A rapid, non-invasive method for measuring live or preserved insect specimens using digital image analysis |
| title_short | Technical note: A rapid, non-invasive method for measuring live or preserved insect specimens using digital image analysis |
| title_sort | technical note a rapid non invasive method for measuring live or preserved insect specimens using digital image analysis |
| url | http://www.sciencedirect.com/science/article/pii/S2589871X19301366 |
| work_keys_str_mv | AT donaldrbourne technicalnotearapidnoninvasivemethodformeasuringliveorpreservedinsectspecimensusingdigitalimageanalysis AT christopherjkyle technicalnotearapidnoninvasivemethodformeasuringliveorpreservedinsectspecimensusingdigitalimageanalysis AT helenenleblanc technicalnotearapidnoninvasivemethodformeasuringliveorpreservedinsectspecimensusingdigitalimageanalysis AT davidberesford technicalnotearapidnoninvasivemethodformeasuringliveorpreservedinsectspecimensusingdigitalimageanalysis |