Path Meander of Male Codling Moths (<i>Cydia pomonella</i>) Foraging for Sex Pheromone Plumes: Field Validation of a Novel Method for Quantifying Path Meander of Random Movers Developed Using Computer Simulations
Measures of path meander are highly relevant to studies of optimal foraging by animals. However, directly recording paths of small animals such as insects can be difficult because of small size or crepuscular activity. Computer simulations of correlated random walkers demonstrated that the rates of...
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| Format: | Article |
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MDPI AG
2020-08-01
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| Series: | Insects |
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| Online Access: | https://www.mdpi.com/2075-4450/11/9/549 |
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| author | Christopher Adams Jeffrey Schenker Paul Weston Lawrence Gut James Miller |
| author_facet | Christopher Adams Jeffrey Schenker Paul Weston Lawrence Gut James Miller |
| author_sort | Christopher Adams |
| collection | DOAJ |
| description | Measures of path meander are highly relevant to studies of optimal foraging by animals. However, directly recording paths of small animals such as insects can be difficult because of small size or crepuscular activity. Computer simulations of correlated random walkers demonstrated that the rates of decay in captures across a rectangular grid of traps when movers were released at its corner can be used to produce calibration curves for quantifying path meander indirectly. Simulations using spatial parameters matching those previously documented for male codling moths (<i>Cydia pomonella</i> (L.)) foraging for female pheromone plumes in the field predicted that meander, as measured in circular standard deviation (c.s.d.) of turn angles between track segments, should be ca. 50° and 30° when the target population density is high vs. low, respectively. Thus, if optimized, the mean value measured for <i>C. pomonella</i> populations encountering an unknown target density should fall between these limits. We recorded decay in <i>C. pomonella</i> catch across a 5 × 5 grid of pheromone-baited traps each separated by 15 m on 39 occasions where batches of ca. 800 males were released 10 m outside the corner of trapping grids arranged in five large Michigan apple orchards. This decay constant was translated into mean c.s.d value for path meander using the standard curve generated by the computer simulations. The measured decay constant for <i>C. pomonella</i> males was negative 0.99 ± 0.02 (S.E.M.), which translates to a path meander of 37 ± 2° c.s.d. Thus, the measured path meander of 37° fell between the 50° and 30° values optimal for dense and sparse populations, respectively. In addition to providing a rare documented example of optimal foraging for odor plumes, this research offers proof-of-concept for a novel approach to quantifying path meander of movers that could prove useful across diverse taxa. |
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| language | English |
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| publishDate | 2020-08-01 |
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| series | Insects |
| spelling | doaj.art-61ea8ba61c774e37a3289a2a6dbec0e82023-11-20T10:37:37ZengMDPI AGInsects2075-44502020-08-0111954910.3390/insects11090549Path Meander of Male Codling Moths (<i>Cydia pomonella</i>) Foraging for Sex Pheromone Plumes: Field Validation of a Novel Method for Quantifying Path Meander of Random Movers Developed Using Computer SimulationsChristopher Adams0Jeffrey Schenker1Paul Weston2Lawrence Gut3James Miller4Department of Entomology, Michigan State University, East Lansing, MI 48824, USADepartment of Mathematics, Michigan State University, East Lansing, MI 48824, USAGraham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, New South Wales 2678, AustraliaDepartment of Entomology, Michigan State University, East Lansing, MI 48824, USADepartment of Entomology, Michigan State University, East Lansing, MI 48824, USAMeasures of path meander are highly relevant to studies of optimal foraging by animals. However, directly recording paths of small animals such as insects can be difficult because of small size or crepuscular activity. Computer simulations of correlated random walkers demonstrated that the rates of decay in captures across a rectangular grid of traps when movers were released at its corner can be used to produce calibration curves for quantifying path meander indirectly. Simulations using spatial parameters matching those previously documented for male codling moths (<i>Cydia pomonella</i> (L.)) foraging for female pheromone plumes in the field predicted that meander, as measured in circular standard deviation (c.s.d.) of turn angles between track segments, should be ca. 50° and 30° when the target population density is high vs. low, respectively. Thus, if optimized, the mean value measured for <i>C. pomonella</i> populations encountering an unknown target density should fall between these limits. We recorded decay in <i>C. pomonella</i> catch across a 5 × 5 grid of pheromone-baited traps each separated by 15 m on 39 occasions where batches of ca. 800 males were released 10 m outside the corner of trapping grids arranged in five large Michigan apple orchards. This decay constant was translated into mean c.s.d value for path meander using the standard curve generated by the computer simulations. The measured decay constant for <i>C. pomonella</i> males was negative 0.99 ± 0.02 (S.E.M.), which translates to a path meander of 37 ± 2° c.s.d. Thus, the measured path meander of 37° fell between the 50° and 30° values optimal for dense and sparse populations, respectively. In addition to providing a rare documented example of optimal foraging for odor plumes, this research offers proof-of-concept for a novel approach to quantifying path meander of movers that could prove useful across diverse taxa.https://www.mdpi.com/2075-4450/11/9/549random walkersoptimal foragingresource findingmover simulations |
| spellingShingle | Christopher Adams Jeffrey Schenker Paul Weston Lawrence Gut James Miller Path Meander of Male Codling Moths (<i>Cydia pomonella</i>) Foraging for Sex Pheromone Plumes: Field Validation of a Novel Method for Quantifying Path Meander of Random Movers Developed Using Computer Simulations Insects random walkers optimal foraging resource finding mover simulations |
| title | Path Meander of Male Codling Moths (<i>Cydia pomonella</i>) Foraging for Sex Pheromone Plumes: Field Validation of a Novel Method for Quantifying Path Meander of Random Movers Developed Using Computer Simulations |
| title_full | Path Meander of Male Codling Moths (<i>Cydia pomonella</i>) Foraging for Sex Pheromone Plumes: Field Validation of a Novel Method for Quantifying Path Meander of Random Movers Developed Using Computer Simulations |
| title_fullStr | Path Meander of Male Codling Moths (<i>Cydia pomonella</i>) Foraging for Sex Pheromone Plumes: Field Validation of a Novel Method for Quantifying Path Meander of Random Movers Developed Using Computer Simulations |
| title_full_unstemmed | Path Meander of Male Codling Moths (<i>Cydia pomonella</i>) Foraging for Sex Pheromone Plumes: Field Validation of a Novel Method for Quantifying Path Meander of Random Movers Developed Using Computer Simulations |
| title_short | Path Meander of Male Codling Moths (<i>Cydia pomonella</i>) Foraging for Sex Pheromone Plumes: Field Validation of a Novel Method for Quantifying Path Meander of Random Movers Developed Using Computer Simulations |
| title_sort | path meander of male codling moths i cydia pomonella i foraging for sex pheromone plumes field validation of a novel method for quantifying path meander of random movers developed using computer simulations |
| topic | random walkers optimal foraging resource finding mover simulations |
| url | https://www.mdpi.com/2075-4450/11/9/549 |
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