Spatial analysis of mass trapping: how close is close enough?

Area of Science:

• Agricultural Entomology
• Pest Management Science
• Chemical Ecology

Background:

• Developing effective mass trapping strategies requires standardized methods for screening novel attractants.
• Trap interference, where traps compete for insects, can significantly impact efficacy.
• Previous methods for assessing trap interference were not standardized.

Purpose of the Study:

• To develop and validate a simple method for quantifying trap interference.
• To assess the potential for mass trapping using different attractants and trap spacings.
• To provide a rapid preliminary assessment for mass trapping development.

Main Methods:

• Utilized 4x4 trap arrays with varying spacings to quantify trap interference.
• Measured the ratio of insect catch in corner traps versus center traps.
• Tested sex pheromones for Lepidoptera (Epiphyas postvittana), Diptera (Dasineura mali), Homoptera (Pseudococcus calceolariae), and a kairomone for Thrips obscuratus.

Main Results:

• Significant trap interference was observed for Dasineura mali even at low densities (16 traps ha⁻¹), with corner:center catch ratios around 5:1.
• Trap competition was evident for Pseudococcus calceolariae sex pheromone lures at spacings under 5m.
• No significant trap competition was detected for Thrips obscuratus with a kairomone at 4m spacings.

Conclusions:

• The ratio of corner to center trap catch in a 16-trap array provides a rapid preliminary assessment for mass trapping potential.
• This method can expedite the development of mass trapping strategies by identifying optimal attractant and spacing combinations.
• Further research on vital rates and dispersal is necessary for precise population suppression predictions.