DEVELOPMENTAL STAGES 17 



A second colour variety is distinctly darker than the normal. The 

 two dorso-lateral bands bounding the median dorsal yellow one become 

 almost jet black, while the face assumes a similar colour. The anten- 

 nae are also much darker than normal. The normal colour type remains 

 much as in the previous instar. 



We have, however, besides these three distinct colour types, grada- 

 tions. Both green and dark varieties are usually much fewer in number 

 than the normal yellowish-brown forms. It must be noted here that 

 all these different varieties can be found among young grasshoppers 

 which have hatched from a single egg-mass, so that there is no possi- 

 bility of our having here distinct but closely-related species. 



An important point in development has, up to the present, not been 

 noted and that is the formation of the wings, which become quite dis- 

 tinct in this instar. An examination of Plate I, Fig. 4 shows them in the 

 form of distinct out-growths (so called wing-buds) from the two posterior 

 divisions of the thorax (meso- and metathorax) above the points of ori- 

 gin of the middle and hind legs. These wing-buds begin to appear in 

 the third instar but are hardly distinct in that stage (see Plate III, 

 Figs. 3 and 4) 



FIFTH INSTAR. (PLATE I, FIG. 6.) 



Length of body ... ... ... 15 — 16"5 mm. 



Length of antennae ... ... 7 — 8 ,, 



Number of segments in antennae ... 24 — 25 



Colour. —The colour variations noted under the previous instar con- 

 tinue here and, in fact, persist up to the last moult, when the insects as- 

 sume the adult form and with it the fairly uniform colour of the adult 

 Eiee Grasshopper. 



The most interesting feature connected with this instar is the 

 appearance of two distinct stages in the formation of the wing-buds. 

 This may be illustrated by giving the record from a single rearing jar, 

 In this particular jar, there were, on the 25th August, fifteen young grass- 

 hoppers (nymphs), all of which had moulted for the fourth time, and 

 hence were in the fifth instar, between the 22nd and 25th August. 

 Eight of these- -six females and two males — had w'ing-buds 

 very similar to thosealready described forthe fourth instar (see Plate III, 

 Fig. 5). The remaining seven — all males — showed the wing-buds in 

 a more advanced stage of development. The buds were folded upward 

 on the meso- and metathorax so that they almost touched the opposite 

 pair dorsally (see Plate IV, Fig. l). 



This interesting observation was later made on a large number of 

 developing Rice Grasshoppers and it was found that, regularly in thia 

 instar, the nymphs split up into two divisions, (1) those •with wing- 

 buds still growing downward and (2) those in which the wing-buds 

 have been folded upward. It was found, further, that these tw^o divi- 

 sions almost, but not quite, exactly coincide with the divisions into 

 female and male hoppers. In no case has a female of the fifth instar 

 been observed with upturned wing-buds. On the other hand, while the 

 great majority of the males of this instar have their wing-buds folded 

 upward, a few (two out of nine in the record given above) are to be 

 R. G. C 



