HOW TO KNOW THE IMMATURE INSECTS 



22a. Prothorax with a long aperture mesad of and connected with the 

 spiracle. Fig. 572 Family TABANIDAE 



The pupae are cylindrical 

 and elongate with thoracic 

 spiracles connected subcutane- 

 ously with a large cavity on 

 the prothorax. 



.Fig. 572. Tobanus losiophthalmus Macq. 



22b. Not as 22a 23 



23a. Head without strong iorwordly directed thorns, at most with 1 

 thorn on base of antenna which is directed to the side: abdominal 

 armature weak« becoming gradually stronger towards apex of 

 basal abdominal segment; apices of hind tarsi at most extending 

 slightly beyond apices of wings; abdomen with 7 pairs of spir- 

 acles 24 



23b. Head usually with strong thorns, or if absent, the abdominal ar- 

 mature is stronger on basal of 2nd segment than it is on apical, 

 or there are less than 7 pairs of abdominal spiracles; apices of 

 hind tarsi usually distinctly beyond apices of wings 26 



24a. Antennal sheaths much thickened at base, apical portion slender, 

 styliform, the whole directed almost straight downward. 

 Fig. 573 Family RHAGIONIDAE 



Fig. 573. Chrysopilus ornotus Say. 



The information concerning 

 the biology of the pupae of 

 this family is quite limited. 



24b. Antennal sheaths thickened throughout their length, the apical 

 portion generally more or less distinctly onnulated, the whole 

 directed either straight sideways or in a slightly downward di- 

 rection 25 



25a. Antennal sheaths showing much more than 10 annulations. 



Subfamily Rhachicerinae, RHAGIONIDAE 



25b. Antennal sheaths showing not more than 10 annulations. 



Fig. 574 Family XYLOPHAGIDAE 



Information about the pupae 

 is very limited. 



Fig. 574. Xylophagus lugens Loew. 



207 



