Figure 3
The visual system of 3rdinstar whirligig beetle larva. A: A 3rd instar larva. B: Group of six stemmata located laterally on the head. C: Top-down view of the brain after removing the head capsule. Larval stemmata are connected to the brain by a fused stemmatal nerve (bundles of retinular axons, arrows). D: A horizontal silver-stained section showing the stemmatal nerve (black arrow), three major larval laminas (LrLA, white arrowheads) and precocious larval lobula plate (LrLOP). The lobula plate is supplied by uncrossed axons from the lamina (asterisk). E-G: Three consecutive horizontal brain sections of another preparation showing the three larval laminas (LrLA, white arrowheads) and the larval lobula plate (LrLOP), which receives uncrossed inputs from the laminas (asterisks). Inset F: Reconstruction from serial Bodian-stained sections of the larval laminas and lobula plate showing dendrites and centrally projecting axons. Scale bars = 5 mm in A; 500 μm in C; 50 μm in D-G.