166 The University Science Bulletin. 



THIRD-INSTAR NYMPH. 



Size. Length, 3.5 mm.; width of thorax, 2.7 mm.; width of head, 2.0 mm. 



Color. The eyes faintly banded with three bars of color, one of them on 

 the inner margins. The general pattern variable; but when defined, like 

 other instars. 



Structural ])eculiarities. The inner emargination of the eye now regular 

 and marked. Ocelli faintly visible in some, while in others unmistakably 

 present. Lateral margin of Mesothorax now a little longer than that of 

 metathorax. 



FOURTH INSTAR NYMPH. 



Size. Length, 4.5 mm.; width of thorax. 3i.6 mm., width of head, 2.4 mm. 



Color. The general pattern as in fifth. The eyes banded by four faint bars, 

 one of which is on inner margin. 



Sttructural 'peculiarities. The lateral margin of mesothorax now is about 

 twice as long as that of the metathoracic margin, due, of course, to the 

 lengthening of the wing pads. The body is covered with closely set short, 

 stout, appressed spines, which show more plainly than in the preceding instar. 

 The ocelli show plainly now. They are located just above the lateral arms 

 of what I take to be the epicranial suture. The nymphal exuvium always 

 shows a Y-shaped rent on the head, and it is on the ui^per margin of the 

 lateral arms of this fissure that the ocelli are located. 



FIFTH INSTAR NYMPH. 



Size. Length, 6.2 mm.; width of thorax, 5.0 mm.; width of head, 3.0 mm. 



Color. Color variable from very light to very dark, and the pattern varying 

 from obscure to distinct. The eyes have five dark bars. There are two pairs 

 of black dots on the face, one above the other, and laterad and below the 

 ocelli. A median black dot on vertex. The pronotum has front two-thirds 

 of lateral margins of prothorax darker. There is a pair of black spots caudo- 

 laterally of each pronotal elevation, of which there are two. The mesonotum 

 has two rectangular black spots on front margin either side of median line. 

 There is a transverse row of four black dots across caudal third of mesonotum; 

 wing pad has a dark rectangular spot on shoulder; the middle of the pad 

 crossed by another dark area; tip and inner margin of pad dark. Two faint 

 dark irregular spots in the outer third of wing pad gives a mottled effect to 

 the whole. A white spot is found on second abdominal segment either side 

 of median line. A row of dark marginal spots, roughly triangular, cover the 

 front two-thirds of the margin of each abdominal segment. There are also 

 two rows of dark submarginal spots, faint and ill defined. The legs are banded 

 with dark bands. The hind tibise have three dark bands besides being dark 

 at the ends. 



Structural -peculiarities. The wing pads of the mesothorax now extend 

 almost to caudal margin of thorax, nearly obscuring lateral margin of meta- 

 thorax. 



