| Title: | Path Meander of Male Codling Moths (Cydia pomonella) Foraging for Sex Pheromone Plumes: Field Validation of a Novel Method for Quantifying Path Meander of Random Movers Developed Using Computer Simulations |
| Author(s): | Adams C; Schenker J; Weston P; Gut L; Miller J; |
| Address: | "Department of Entomology, Michigan State University, East Lansing, MI 48824, USA. Department of Horticulture, Oregon State University, Hood River, OR 97031, USA. Department of Mathematics, Michigan State University, East Lansing, MI 48824, USA. Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, New South Wales 2678, Australia" |
| ISSN/ISBN: | 2075-4450 (Print) 2075-4450 (Electronic) 2075-4450 (Linking) |
| Abstract: | "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 (Cydia pomonella (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 degrees and 30 degrees when the target population density is high vs. low, respectively. Thus, if optimized, the mean value measured for C. pomonella populations encountering an unknown target density should fall between these limits. We recorded decay in C. pomonella catch across a 5 x 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 C. pomonella males was negative 0.99 +/- 0.02 (S.E.M.), which translates to a path meander of 37 +/- 2 degrees c.s.d. Thus, the measured path meander of 37 degrees fell between the 50 degrees and 30 degrees 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" |
| Keywords: | mover simulations optimal foraging random walkers resource finding; |
| Notes: | "PubMed-not-MEDLINEAdams, Christopher Schenker, Jeffrey Weston, Paul Gut, Lawrence Miller, James eng 1411411/National Science Foundation/ Switzerland 2020/08/23 Insects. 2020 Aug 19; 11(9):549. doi: 10.3390/insects11090549" |
