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ENTOMOLOGICAL NEWS 



[Apr., '17 



of the red pigment in the abdomen so conspicuous in older nymphs and 

 adults. White with the red eyes the only conspicuous marking. 



Structural details : The absence of the median abdominal carina from 

 the venter, as is the case also with N. undulata nymphs, is the first and 

 most striking peculiarity. The interspace between the eyes is large. Beak 

 four-jointed as in adult. Tarsi all one-jointed, terminating in two claws. 

 The spiny armature of fore legs is more generalized than in later 

 forms. The fringe of the hind legs confined to the margins of the 

 tarsi. 



THE OLDER NYMPHS. 



In order that space may be conserved, a table of measurements for 

 the various instars is presented below and a discussion of the changes 

 in structure as development proceeds appended. 



MEASUREMENTS IN MILLIMETERS OF NYMPHS OF B. margaritacea. 



The adults of this species are separated in the synoptic ta- 

 ble from the other two species on the basis of the body length, 

 which is greater than 6 mm. This, with a diagnosis of the in- 

 stars from structural characters, may serve to separate the 

 nymphs of this species from those of the others. The table 

 of measurements above is based on an average of ten speci- 

 mens of each instar. A larger number would be desirable to 

 obtain figures dealing with ratio of growth. The writer be- 

 lieves that an examination of a sufficiently large amount of 

 material would show for head-widths and limb measurements 

 a ratio of i 11.25. That is to say, the width of the head of the 



* Bueno gives length of species 6.7-8.1, lat. 2.23 mm. 



