hungerford: aquatic hemiptera. 147 



Shape. Broader than in first instar. 



Structural Peculiarities. The fore tarsal claws which were nearly 

 equal in the first instar are now very unequal, one being- greatly reduced. 

 See plate XVII, figures 8 and 9. "The antennae are now distinctly 2-seg- 

 mented and a little more slender, basal segment being about half as long 

 as the second." — Bueno 



Third Instar. 



Size. Length, 8 to 9 mm.; width 3.7 to 4 mm. Other measurements on 

 chart. 



Color. Dorsum: General color olivaceous; eyes very dark red. The 

 head and thorax mottled with light spots. Meso- and metathorax each 

 with two light spots on their fore and rear margins, giving the effect of 

 each segment being banded with a dark band. This pattern continues 

 along the lateral edge of abdomen producing a similar effect. Besides 

 these six light areas on either side, there are two other rows on either side 

 consisting of more or less rectangular spots. 



Venter: General color gray with a yellowish tinge. Femora, tro- 

 chanters and cox£e of all legs nearly colorless. Tibife yellow banded with 

 dark, all tibiae with 3 dark bands; tip of fore tarsi marked by dark band; 

 tips of other tarsi slightly darker than remaining part. Tips of all 

 femora dark banded. The prothorax is crossed on either side by a black 

 subm_arginal band, these bands slightly constricted across the mesothorax 

 and fork into two as they cross the metathorax. Base of the abdomen is 

 marked on first three segments with some black. The remainder is 

 gray with the checkering or banding of the flattened sides of the bug 

 as described for the dorsum. 



Structural Peculiarities. The antennae are distinctly 3-segmented, still 

 club shaped, and about twice as long as wide. The wing pads are as in 

 figure on plate XVII. They extend back on the metathorax so that the 

 marginal exposed line of this segment is about one-third the entire line 

 of meso- and metathorax together. 



Fourth Instar. 



Size. Length, 11.5 mm.; width, 6.3 mm. Other measurements on 

 chart. 



Color. General color as before. A dai'k band on the margin of vertex 

 and a submarginal band on prothorax. 



Shape. About as before. The wing-pads now reach about four-fifths 

 of the total m.arginal length of the meso- and metathorax taken together. 

 See plate XVII. The antennas are developing two lateral processes in 

 this stage. 



Fifth Instar. 



Size. Length, 16 mm.; width, 8.5 mm. to 9 mm. Other measurements 

 below. 



Color. Deeper than in previous instars. Wing-pads greyish green; 

 abdomen yellowish green with the barring effect along lateral margins. 



