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ENTOMOLOGICAL NEWS. 



[June, '17 



In the light of Tillyard's work with hatching dragonfly 

 nymphs and the work of Hoppe and Brocher on the respira- 

 tion of older notonecta nymphs, careful and extended obser- 

 vations on the respiratory activity of the newly hatched water 

 bugs are to be desired. 



THE NYMPHAL INSTARS. 



First Instar. Size : see table below. Color : General body white, 

 eyes red, hairs and spines black, antennae smoky black. When first 

 hatched the abdomen especially transparent and the movements of the 

 organs plainly visible within. Tarsal claws all conspicuously black. 



Structural peculiarities. The most characteristic feature of the first 

 instar is the absence of the tuft of hairs which in all succeeding instars 

 is found on a median ventral carina of the abdomen. The eyes are 

 relatively far apart. The antennae are apparently two-segmented and 

 directed downward (really three segments). The tarsi are all one- 

 segmented and end in two claws. The tarsi of the hind legs are fringed 

 with hairs. The middle femora are furnished on their caudo-ventral 

 margins with two strong bristles set upon elevations. 



Second instar. The presence of the tuft and fringe of hairs on the 

 ventral abdominal carina is the chief addition over that of the previous 

 stage. The rear margin of the middle femora are now equipped with 

 three strong bristles and there is a suggestion of the tooth or spine 

 that becomes prominent in the succeeding instar. Antennae 3-seg- 

 mented. First segment short, disc-like, second somewhat globose and 

 third elongate. 



Third instar. The caudal margin of the mesothoracic femur now 

 carries a well developed tooth as well as the three stout spines noted 



TABLE OF MEASUREMENTS. 



