/ 



The origin and development of the wings of Coleoptera. 569 



n.S nervous system tib tibia 



sac.al wing sac tar tarsus 



s-hdrm-sp sub-hypodermal space tr trachea 

 sp spiracle tro trochanter 



sq scale tr^ol tracheole 



tr.an anal trachea ^ • ^ l i ^ i r 



tr.COS costal trachea | f^ *^"^"^^^| ^^'^"^^ %^^^' 



, u i. 1 i. u I >^he nomenclature oi Com- 



tr.s-COS subcostal trachea „ t,t /.r,r^^^^ 



tr cub cubital trachea '^'^^^^ ^ Needham 1899 . 



Vf • i/CvU üllUltdl LI dL- lied ;■ /^ n- , ,i 



tr.m médius trachea Corresponding to these are 



tr. rm ramous trachea ^"^^" designated ve. an anal 



^ , vein etc. 



V ventral ' 



Plate 14, 



To show the development of the wings as seen in surface view by 

 graphic reconstruction from serial sections. Figs. 1 — 6 L. decenilineata, 

 7 — 10 P. variabilis., 11 — 13 0. scabra. 



Leptinotarsa decemlineata. 

 Fig. 1. Elytron from a larva immediately after ecchysis at the 

 beginning of the third instar. 70 : 1. 



Fig. 2. Wings at the middle of the third instar. 70 : 1. 

 Wings at the end of the third instar. 70 : 1. 

 Wings at the beginning- of the prepupal stage. 70 : 1. 

 Wings at the end of the first day of the prepupal period. 



70 

 40 



Wings at the end of the third day of the prepupal period. 



Phymatodes variabilis. 



Wings at the beginning of the prepupal stage. 70 : 1. 

 Wings about 2 weeks later than Fig. 7. 70 : 1. 

 Wings about 8 days before pupation. 70 : 1. 

 Fig. 10. Wings about 3 days before pupation. 70 : 1. 



Osmoderma scabra. 



Fig. 11. Elytron 15 — 16 weeks before pupation. 50 : 1. 

 Fig. 12. Elytron about 8 weeks before pupation. 50 : 1. 

 Fig. 18. Elytron about 2 weeks before pupation. 50 : 1. 



Plate 1 5. 



Tho show position and development of the wing fundament in the 

 early larva. 



Leptinotarsa decemlineata. 



Fig. 14. Transverse section through mesothorax of larva of the 

 first instar showing wing fundament. 100 : 1. 



