THE HORNED SQUASH BUG. 31 



the head. Its habits are unknown, but it doubtless also lives on 

 cucurbits. 



Still another species is likely to be mistaken for it. This is Archi- 

 merus calcarator Fab. It is a little larger than Anasa armigera, but 

 from that species it may at once be known by its much thickened and 

 multispinose femora. 



THE EGG. 



The egg closely resembles that of A. tristis, so nearly in fact that it 

 is difficult to distinguish them otherwise than by color. It is beau- 

 tiful, bright, shining coppery, lighter and with a less bronzy appear- 

 ance than in tristis. It is also just perceptibly narrower at each end as 

 viewed from below. Length, 1.50 to 1.60 mm ; width, 1.15 mm . 



The egg is shown at b and bb, much enlarged, and the reticulation of 

 the surface is indicated by a much enlarged section at c. 



NYMPHS. 



Throughout the five stages of the nymph, armigera is so different 

 from tristis that there is no danger of anyone mistaking one for the 

 other. This applies to color, structure, and form about equally. The 

 following most observable differences may be briefly indicated in 

 tabular form for convenience. 



NYMPHS COMPARED. 



Armigera. Tristis. 



First stage. 



White, with red eves, antennae and red- Black, with green abdomen. Antennae 

 banded legs and abdomen. Antennas shorter than body, joints subequal. 



longer than body, penultimate joint Legs nearly uniform black, 

 widest. 



Second stage. 



Much like first stage; penultimate an- Much as in first stage, abdomen gray, 

 tennal joint still wider. Legs banded thorax lighter, 

 with brown. 



Third stage. 



Three segments of thorax scale-like, pro- Three segments of thorax not produced, 

 longed posteriorly, and overlapping; re flexed, or dentate. Connexivum fee- 

 sides reflexed, strongly dentate and bly subdenticulate or subspinose. 

 denticulate. Connexivum also strong- 

 ly dentate. 



Fourth stage. 



As above, the thorax becoming wider and Pronotum feebly overlapping. Meso- 



the reflection and denticulation more and metanotum produced. 



pronounced. 



Fifth stage. 



Thorax produced at sides and otherwise Thorax not produced. Body colors gray, 



much as in adult. Body variegated dotted with black. Legs black at first, 



with brown and yellow. Legs witb becoming spotted before last molt, 

 round black dots. Spines of head ap- 

 pear. 



