20. Pronotum narrower than head, never covering head (20 A). ORDERSOPTERA...TERMINTE
Pronotum broader than head, often covering head (20 B). ORDER ORTHOPTERA............
.......................................................................................................COCKROACH
21. Flattened laterally (21 A). ORDER SIPHONATERA............................................FLEA
Flattened dorso-ventrally (21 B)...........................................................................22
22. Foot terminating in protrusible bladder (22 A). ORDER THYSANOPTERA........THRIPS
Foot not terminating in protrusible bladder (22 B)..................................................23
Figure 2-2. Standard identification key (continued)
MD0170
2-11