ARS | Publication request: Analysis of vertical distributions and effective flight layers of insects: three-dimensional simulation of flying insects and catch at trap heights

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 10, 2011
Publication Date: October 1, 2011
Citation: Byers, J.A. 2011. Analysis of vertical distributions and effective flight layers of insects: three-dimensional simulation of flying insects and catch at trap heights. Environmental Entomology. 40(5):1210-1222.

Interpretive Summary: The average height and distribution of flight (standard deviation abbreviated SD) in the vertical direction was estimated for over 100 insect species from their catches on trap heights reported in the literature. The repetitive equations for calculating mean height and SD are presented. The mean flight height for 95% of the studies in the literature varied from 0.17 to 5.40 m, and the SD from 0.12 to 3.83 m. The SD increased as the mean flight height increased. In addition, the vertical trap catches usually fit normal distributions (bell-shaped curves) reasonably well. The SD was used to calculate an effective flight layer that with field measurement of the spherical effective attraction radius of pheromone-baited traps can be used in simulation models of mass trapping and mating disruption control methods using pheromones. The effective attraction radius also serves to reveal the attractive strength and efficacy of suspected pheromone blends for control and monitoring. To determine the reliability of mean flight height and SD calculations from field trapping data from the scientific literature, computer simulations of flying insects in three dimensions were performed. The simulations caused individuals to roam freely at random but such that the population distributed vertically according to a normal distribution of specified mean and SD. Within this volume, spherical traps were placed at various heights to determine the effects on catch and SD. The results indicate that data from previous field studies when analyzed by the repetitive equations should provide good estimates of the population mean height and SD of flight for use in simulation models of mass trapping and monitoring densities of pest insects.

Technical Abstract: The mean height and standard deviation (SD) of flight is calculated for over 100 insect species from their catches on trap heights reported in the literature. The iterative equations for calculating mean height and SD are presented. The mean flight height for 95% of the studies varied from 0.17 to 5.40 m, and the SD from 0.12 to 3.83 m. The relationship between SD and mean flight height (X) was SD = 0.711X-0.7849, n = 123, R2 = 0.63. In addition, the vertical trap catches were fit to normal distributions and analyzed for skew and kurtosis. The SD was used to calculate an effective flight layer used in transforming the spherical effective attraction radius (EAR) of pheromone-baited traps into a circular EARc for use in two-dimensional encounter rate models of mass trapping and mating disruption using semiochemicals. The EAR/EARc also serves to reveal the attractive strength and efficacy of putative pheromone blends. To determine the reliability of mean flight height and SD calculations from field trapping data, simulations of flying insects in three dimensions (3D) were performed. The simulations used an algorithm that caused individuals to roam freely at random but such that the population distributed vertically according to a normal distribution of specified mean and SD. Within this 3D arena, spherical traps were placed at various heights to determine the effects on catch and SD. The results indicate that data from previous field studies when analyzed by the iterative equations should provide good estimates of the population mean height and SD of flight.