Ronny Rosner, Joss von Hadeln, Ghaith Tarawneh & Jenny C. A. Read. A neuronal correlate of insect stereopsis. Nature Communications volume 10, Article number: 2845 (2019) 

Abstract
A puzzle for neuroscience—and robotics—is how insects achieve surprisingly complex behaviours with such tiny brains. One example is depth perception via binocular stereopsis in the praying mantis, a predatory insect. Praying mantids use stereopsis, the computation of distances from disparities between the two retinal images, to trigger a raptorial strike of their forelegs when prey is within reach. The neuronal basis of this ability is entirely unknown. Here we show the first evidence that individual neurons in the praying mantis brain are tuned to specific disparities and eccentricities, and thus locations in 3D-space. Like disparity-tuned cortical cells in vertebrates, the responses of these mantis neurons are consistent with linear summation of binocular inputs followed by an output nonlinearity. Our study not only proves the existence of disparity sensitive neurons in an insect brain, it also reveals feedback connections hitherto undiscovered in any animal species.

For further info, please read the paper Rosner et al. 2019 and the report  Brain cells for 3D vision discovered

Ronny Rosner, Joss von Hadeln, Ghaith Tarawneh & Jenny C. A. Read. A neuronal correlate of insect stereopsis. Nature Communications volume 10, Article number: 2845 (2019) 

Brain cells for 3D vision discovered Newcastle University News