How to count your bugs?

Abstract

Ability to estimate local population density of an insect is critical in many fields, from pest management to conservation. No method currently exists that reliably connects trap catch with the insect population density, including the corresponding uncertainty. Here we report a simple and universal predictive relationship for a probability of catching an insect located a given distance away from the trap. This relationship allows to estimate, from a single catch, the most likely population density along with its statistical upper and lower bounds. To test the generality of this equation we used 10 distinct trapping data sets collected on insects from 5 different orders and major trapping methods: chemical-baited and light. For all of the datasets the equation faithfully (R ̅=0.91) describes the relationship between location of an insect and probability to catch it. The ability to estimate absolute population density from a single trap catch will significantly improve our understanding of insect population dynamics and allow for more effective research, management, and conservation programs.