KEY TO THE PRINCIPAL LOCAL ORDERS OF THE CLASSES PROTURA, DIPLURA, COLLEMBOLA, AND INSECTA (ACTIVE IMMATURE STAGES)

(From Dr. Marvin Harris, Professor of Entomology, Texas A&M University)

1a. NYMPHS of hemimetabolous insects, and YOUNG of Apterygota, Protura, Diplura, and Collembola; thorax of older forms bearing wing-pads except in wingless species; tarsus usually composed of more than one segment (exceptional forms occur, such as some lice); compound eyes usually present; mouthparts and general appearance similar to adults.............. 2

b. LARVAE of holometabolous insects; thorax showing no evidence of wingpads; tarsus with one segment or none, or legs entirely lacking; no compound eyes present although groups of ocelli may occur; general appearance different from that of adults..19