EXPI.ANATION OF PivATK 20. 



This plate illustrates the ontogeny of the coloration upon the abdominal 

 segments and the hind wings of several species of Leptinotarsa. 



Figs. I to 5, L. oblongata. 



Figs. 6 to lo, L. undecimlineata. 



Figs. II to 15, Z. tmdecimlineata. 



Figs. 16 to 20, L. multitceniata. 



Figs. 21 to 24, Z. signaiicollis. 



Figs. 25 to 28, Z. oblongata. 



Figs. 29 to 32, Z. dileda. 



