Target detection in insects: optical, neural and behavioral optimizations

Abstract

Motion vision provides important cues for many tasks. Flying insects, for example, may pursue small, fast moving targets for mating or feeding purposes, even when these are detected against self-generated optic flow. Since insects are small, with size-constrained eyes and brains, they have evolved to optimize their optical, neural and behavioral target visualization solutions. Indeed, even if evolutionarily distant insects display different pursuit strategies, target neuron physiology is strikingly similar. Furthermore, the coarse spatial resolution of the insect compound eye might actually be beneficial when it comes to detection of moving targets. In conclusion, tiny insects show higher than expected performance in target visualization tasks.

A Novel Interception Strategy in a Miniature Robber Fly with Extreme Visual Acuity

“…Consistent with the CBA model, we found that when pursuing a bead moving at constant speed, the range vectors were close to being parallel across most of the trajectory: for 80% of the flight time, the absolute difference between each range vector and the trajectory median range vector was on average less than 3° (Figures 2A1–2A3; n = 63 attacks to a 1.3 mm bead). By applying proportional navigation, the guidance law associated with the CBA model [4, 7], a pursuer can control the necessary steering command to null any change in the velocity of the target, thereby keeping the range vectors parallel and actively maintaining the CBA (Figures S1G and S1H). We tested the CBA mechanism of Holcocephala by decelerating or reversing the bead during the attack (Movie S1).…”

“…When this object is far away, we base the trajectory on the target’s location relative to an external frame of reference [1]. This process forms the basis for the constant bearing angle (CBA) model, a reactive strategy that ensures interception since the bearing angle, formed between the line joining pursuer and target (called the range vector) and an external reference line, is held constant [2, 3, 4]. The CBA model may be a fundamental and widespread strategy, as it is also known to explain the interception trajectories of bats and fish [5, 6].…”

Unraveling the functional organization of lobula complex in the mantis brain by identification of visual interneurons

“…Vision plays an important role in insect behaviors, such as flight control (Srinivasan, ), prey detection (Gonzalez‐Bellido, Fabian, & Nordström, ), and collision avoidance (Simmons, Rind, & Santer, ). Large interneurons that respond to visual features relevant to these behaviors have been found in the third visual neuropil, lobula complex (LOX), in the optic lobe of the insect brain.…”

Decision‐making and motor control in predatory insects: a review of the praying mantis

“…When dragonflies pursue and approach flying prey, they adopt a different tactic to tracking, called interception (Olberg, ; Gonzalez‐Bellido et al ., for review). When tracking, the pursuer aims directly at the perceived location of the target.…”

“…Many use vision as the primary sense to detect prey (e.g. Gonzalez-Bellido et al, 2016) and some use cues from other modalities, including mechanoreception (e.g. Montgomery, 1982;Fertin & Casas, 2007) and chemoreception (e.g.…”