To clearly show the position of different neuropils, the cortex is removed. (A) Ventral view. A total of 24 neuropils in the central nervous system were reconstructed, including 19 in the brain, a connective between the labial sensory center and the prothoracic ganglion, three thoracic neuropils, and a merged abdomen neuropil. The protocerebrum, deutocerebrum, and tritocerebrum are fused and form an esophageal foramen through which the alimentary canal passes. Readers are encouraged to see the 3D PDF to learn spatial relationships of the neuropils. (B) Left-lateral view. Left half of the neuropils are removed. (C) Front view. AbN, abdominal nerve; AG, abdominal ganglion; AL, antennal lobe; AMMC, antennal mechanical and motor center; AN, antennal lobe; AOTU, anterior optic tubercle; CA, calyx; CE, 601 compound eye; CX, central complex; FLA, flange; INP, inferior neuropil; LBN, labial nerve; LA, lamina; LBS, labial sensory center; LN1, proleg nerve; LN2, mesoleg nerve; LN3, metaleg nerve; LO, lobula; LP, lobula plate; MED, medulla; ML, medial 603 lobe; OSN, olfactory sensory nerve; PB, protocerebral bridge; PED, pedunculus; PRW, prow; SAD, saddle; SPS, superior posterior slope; SLNP, superior lateral neuropil; TG1, prothoracic ganglion; TG2, mesothoracic ganglion; TG3, metathoracic ganglion; VPS, ventral pharyngeal sensory center. (D) A compound eye of Sample 1. The compound eyes of the first instar nymph comprise less ommatidia than the adult. Most crystalline cones of the ommatidia have four compartments, and a small number of the ommatidia have five compartments. The yellow asterisks indicate the crystalline cones (CCs) in an ommatidium with five Samper cells (SCs). The white asterisks indicate CCs in an ommatidium with four SCs. Rh, rhabdom. (E) The compound eye of Sample 2 containing 42 ommatidia. CN, cornea. (F) Top view of the compound eye of Sample 2. All 42 ommatidia are shown. Axis labels are the same as those used in Figure 1.