Bark beetles as lidar targets and prospects of photonic surveillance

Abstract

Forestry is raising concern about the outbreaks of European spruce bark beetle, Ips typographus, causing extensive damage to the spruce forest and timber values. Precise monitoring of these beetles is a necessary step towards preventing outbreaks. Current commercial monitoring methods are catch‐based and lack in both temporal and spatial resolution. In this work, light scattering from beetles is characterized, and the feasibility of entomological lidar as a tool for long‐term monitoring of bark beetles is explored. Laboratory optical properties, wing thickness, and wingbeat frequency of bark beetles are reported, and these parameters can infer target identity in lidar data. Lidar results from a Swedish forest with controlled bark beetle release event are presented. The capability of lidar to simultaneously monitor both insects and a pheromone plume mixed with chemical smoke governing the dispersal of many insects is demonstrated. In conclusion, entomological lidar is a promising tool for monitoring bark beetles.

High Dynamic Range in Entomological Scheimpflug Lidars

“…While insect cross sections can be characterized fairly accurately in the laboratory [25], [52], [53], they are challenging to estimate accurately remotely beyond the first digit. Such estimate relies on the assumption that a) the insect is much smaller than the beam, b) that the insect does not transit peripherally and c) that the beam is top-hat rather than Gaussian, see discussion [54].…”

Feasibility of Insect Identification Based on Spectral Fringes Produced by Clear Wings

“…Compared to conventional trap-based methods, laser remote sensing [17,18] can provide unbiased data on insect activity and flux in situ with very high spatial and temporal resolution [19]. Such information could be used to monitor pests [20], track the spread of disease vectors [21], and monitor and manage agricultural pests or pollinators [22]. Machine vision and imaging-based techniques have been reported in combination with traps [23,24], but focusing challenges imply that recognition of anatomical details is difficult for free-flying insects [25].…”

Weak population genetic structure in Eurasian spruce bark beetle over large regional scales in Sweden

“…Dispersal distances, especially rare dispersal events over long distances, are typically extremely challenging to monitor using standard ecological techniques such as mark‐recapture (Doležal et al, 2016; Duelli et al, 1997; Helland et al, 1989; Schlyter, 1992; Weslien & Lindelöw, 1990; Zolubas & Byers, 1995). As rare long‐distance dispersal can be a first step toward new outbreaks, novel methods for monitoring such dispersal and hence the potential for building up the numbers of individuals needed to cause outbreaks are thus needed (Li et al, 2021).…”

“…As rare long-distance dispersal can be a first step toward new outbreaks, novel methods for monitoring such dispersal and hence the potential for building up the numbers of individuals needed to cause outbreaks are thus needed (Li et al, 2021).…”