Author
Byers, John |
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/27/2007 Publication Date: 12/1/2007 Citation: Byers, J.A. 2007. Simulation of mating disruption and mass trapping with competitive attraction and camouflage. Environmental Entomology 36:1328-1338. Interpretive Summary: Mass trapping and mating disruption of insects are similar methods that use semiochemical dispensers with and without traps, respectively, in the field to reduce mating by removing individuals and disrupting communication. Simulation models of these two methods were developed based on correlated random walks (CRW) of flying male moths (multiple mating) in an area. The males could encounter pheromone from usually stationary female moths (mating once) and from pheromone dispensers (with or without traps) both represented spatially as a particular effective attraction radius (EAR). In various simulations, parameters of dispenser (density and EAR), female (density, EAR, and stationary periods), and male (density and waiting times in EAR of dispensers or females) were varied while the male CRW parameters (speed, turning angle, and step size) were realistic and remained constant. The relationships between increasing values of these various parameters and the resulting times for all females to mate in the mating disruption model and the percentages of females mating in the mass trapping model are reported. The models indicated there was no difference in mating disruption between a higher density of dispensers with smaller EAR or a lower density of dispensers with a compensating larger EAR when male waiting time was constant regardless of EAR. However, when the waiting time was increased in proportion to dispenser EAR, then fewer dispensers with larger EAR were more effective in prolonging mating times than more numerous ones with smaller EAR. There was no effect of longer waiting periods on larger EAR in the case of mass trapping because males were caught. When costs of pheromone are substantial, however, more numerous dispensers of smaller EAR would be more economical since dose-response curves in previous studies indicate release rate must increase exponentially to achieve a linear increase in EAR. The effect of waiting times of males in EAR of dispensers and in EAR of females was incorporated into an effective male speed parameter that increased over time as the calling female density decreased through mating. Simulations with this dynamic male speed gave results similar to those with a constant male speed and waiting period as female density declined. The models compare mating disruption and mass trapping under identical conditions and are useful in understanding the variables needed for successful control programs. Technical Abstract: Mass trapping and mating disruption of insects are similar methods that use semiochemical dispensers with and without traps, respectively, in the field to reduce mating by removing individuals and disrupting communication. Simulation models of these two methods were developed based on correlated random walks (CRW) of flying male moths (multiple mating) in an area. The males could encounter pheromone from usually stationary female moths (mating once) and from pheromone dispensers (with or without traps) both represented spatially as a particular effective attraction radius (EAR). In various simulations, parameters of dispenser (density and EAR), female (density, EAR, and stationary periods), and male (density and waiting times in EAR of dispensers or females) were varied while the male CRW parameters (speed, turning angle, and step size) were realistic and remained constant. The relationships between increasing values of these various parameters and the resulting times for all females to mate in the mating disruption model and the percentages of females mating in the mass trapping model are reported. The models indicated there was no difference in mating disruption between a higher density of dispensers with smaller EAR or a lower density of dispensers with a compensating larger EAR when male waiting time was constant regardless of EAR. However, when the waiting time was increased in proportion to dispenser EAR, then fewer dispensers with larger EAR were more effective in prolonging mating times than more numerous ones with smaller EAR. There was no effect of longer waiting periods on larger EAR in the case of mass trapping because males were caught. When costs of pheromone are substantial, however, more numerous dispensers of smaller EAR would be more economical since dose-response curves in previous studies indicate release rate must increase exponentially to achieve a linear increase in EAR. The effect of waiting times of males in EAR of dispensers and in EAR of females was incorporated into an effective male speed parameter that increased over time as the calling female density decreased through mating. Simulations with this dynamic male speed gave results similar to those with a constant male speed and waiting period as female density declined. The models compare mating disruption and mass trapping under identical conditions and are useful in understanding the variables needed for successful control programs. |