1 Description

Historically, most insect chronoecological research has used direct observations, cameras, and/or infrared beam-based monitors to quantify movement across timed intervals. Although many systems are cheaper than the traditional infrared locomotor activity monitors (e.g., DAM/LAM), these options can remain complicated to build, computationally intensive to setup/process, and/or unable to accommodate large-bodied insects (i.e., not Drosophila).

To fill this gap, we developed the affordable, imaging Locomotor Activity Monitor (iLAM) for activity quantification. The iLAM utilizes a Raspberry Pi Zero W computer and night-vision camera inside a flight cage to regularly photograph a population of insects at user-defined intervals.

Customizable, modular R-scripts process consecutive images with imager and output a file containing the number, size, location, and timing of all identified movements. Movement data can be converted into DAM format or directly analyzed within the Rethomics framework.

Out-of-the-box functions can be downloaded and installed from our iLAMtools R package by:

library(devtools)
devtools::install_github("iLAMtools/iLAMtools", force=TRUE)
library(iLAMtools)
iLAM Workflow

Figure 1.1: iLAM Workflow

Representative firefly movements identified by iLAM system

Figure 1.2: Representative firefly movements identified by iLAM system

This resource provides detailed instructions for (1) iLAM construction, (2) Raspberry Pi setup, (3) Image analysis in R, (4) conversion of iLAM output to DAM format in R, and (5) Sample results using Rethomics.