A method for low‐cost, low‐impact insect tracking using retroreflective tags

Abstract

1. Current methods for direct tracking of individual bee movement behaviour have several limitations. In particular, the weight and size of some types of electronic tag may limit their use to larger species. Radars and other electronic systems are also often large and very expensive to deploy. A tool is needed that complements these electronic-tag methods. In particular one that is simple to use, low-cost, can have a high spatial resolution and can be used with smaller insects.2. This paper presents a candidate method that uses retroreflective tags. These are detected using a camera with a global electronic shutter, with which we take photos with and without a flash, the tags can be detected by comparing these two photos. The small retroreflective tags are simple and light-weight, allowing many bees to be tagged at almost no cost and with little effect on their behaviour.3. We demonstrate this retroreflector-based tracking system (RTS) with a series of simple experiments: Training and validation with a manually positioned tag; Case studies of individual bees; Tracking multiple bees as they forage in a garden; Use of real-time monitoring to allow easy re-observation to enable a simple floral preference experiment; and a very brief experiment with 3D path reconstruction (integrating two devices). We found we could detect bees to a range of about 35m with the current configuration. 4. We envisage the system will be used in future to increase detection rates in mark-re-observation studies; provide 3D flight path analysis; and for automated long-term monitoring. In summary, this novel tracking method has advantages that complement those of electronic-tag tracking which we believe will lead to new applications and areas of research.

High Resolution Outdoor Videography of Insects Using Fast Lock-On Tracking

“…On the other hand, retroreflectors return most incoming energy to within a small angle of the incident direction, and may be suitable as markers when combined with paraxial illumination such as an LED near the camera lens. Retroreflective markers are widely used in commercial (human) motion-capture systems, and have already been used in a variety of insect tracking tasks [7, 20, 21, 22]. Our own preliminary work was promising [23] and here we report a full follow-up.…”

Preliminary Experimental Trial of Effects of Lattice Fence Installation on Honey Bee Flight Height as Implications for Urban Beekeeping Regulations

“…For example, attaching radio transmitters and radio-frequency identification tags have weaknesses such as the influences on the insects, time required for attaching, limited number of samples, and short observable distance [19]. Visual and video camera analyses are also disadvantageous in terms of the accuracy and time required [21]. The present study used a 3D laser scanner, which has rarely been used for determining the location of flying insects.…”

“…To date, various methods have already been developed for the spatial localization of flying small animals such as insects in the wild [20,21]. In general, visual and camera measurements have weaknesses in terms of accuracy, labor, and observable range.…”

“…Harmonic radar can be utilized over long distances, but requires large and expensive equipment, making it less practical. The retroreflector-based tracking system can track the behavior of honeybees within 35 m at low cost [21], but it is difficult to acquire numerous individuals in a short time. Tauc et al [23] showed that their light detection and ranging system could accurately detect the spatial location of individual insects flying more than 100 m away.…”

Evolutionary Ecology of Plant-Arthropod Interactions in Light of the “Omics” Sciences: A Broad Guide

“…This gives an idea of the diversity of pollinators and their visitation frequencies. An alternative is the use of radars, such as telemetry and electronic tagging, that combined with cameras allow tracking individual pollinators and flower visitations ( Hagen et al, 2011 ; Abdel-Raziq et al, 2021 ; Smith et al, 2021 ; Sun and Gaydecki, 2021 ). Likewise, quantum dots (semiconductor nanocrystals) can be used as pollen-grain labels to study the fate of the pollen ( Minnaar and Anderson, 2019 ).…”