16 THE JOLA OR DECCAN GRASSHOPPER 
favourable. In any case, where such a marked variation 
in size exists, it is clear that the measurements given 
above for the various nymphal instars are only approxi- 
mate and cannot be used in distinguishing one instar from 
another. [For this purpose, the structure of the antenne, 
the development of wing buds, changes in colour and the 
development of the posterior end of the abdomen will 
furnish the necessary information, and with a little 
practice one is able to identify the instar of a particular 
nymph with a fair degree of accuracy. 
The table on page 17 gives the results of three separate 
rearings, and these records may be taken as typical. 
From this we get the following periods for the 
various instars :— 
Rearing A :—1st instar oer ... 138—19 days 
inden 5. aa te 4 ee 
ata eee Wag ee 3 es Wy Pee 
Ath  ,, me me 
Sth ,, ee so LIZ 19- 
6th .? 18-26 <5, 
Total length of dev plopment for individuals 
with 5 instars Fe ... 86—87_,, 
Total length of development for individuals 
with 6 instars a 2.6 MOO = LD ieee 
Rearing B :—1st instar - Bend (eet sae 
Onduee,, arts a8) A= 
Srduae: ae os. 14--18';, 
Ath ~,, oe see to Orees, 
Sthy=",, wwe ... 14—19 ,, 
Gth ,, soe AB 199 
Total length of development fot individuals 
with 5 instars ... 81—84 ,, 
Total length of development for individuals 
with 6 instars bis ... 85—89 ,, 
Rearing C :—1st instar ne Ae all peaeiae oe 
Qnd ,,; iP oP ee 1 
Stan ae oh .. 12-14 ,, 
Ath -~*;, he sat LB LTA 
tliat, ie .. 13—14 ,, 
Gihe-,; 17—24 ,, 
Total length of development oe fagculie | 
with 5 instars 68 & 
Total length of development for indiv iduala 
with 6 instars mes 79—88 _,, 
The nymphal instars are thus approximately two to 
two and a-half weeks in length. The sixth instar is some- 
what longer than the rest or from two and a-half to three 
