Harmonia axyridis , fourth larval instar: (18) head, dorsal view; (19) mandible; (20) antenna; (21) stemmata; (22) maxillary palpus; (23) labial palpus; (24) tarsal claw; (25) mesothoracic spiracle; (26) abdominal spiracle. Scale bars: 18 = 200 µm; 19, 21, 24 = 100 µm; 20, 23, 25, 26 = 20 µm; 22 = 50 µm.