June, ’20] 
HAYES: SOME KANSAS LACHNOSTERNA 
313 
A combination of the maximum, minimum, and average periods of 
the larval and prepupal stages representing the complete larval stage 
is shown in Table VII. 
Among the two-year grubs, the combined maximum of the two 
stages was greatest in the case of L. rubiginosa with a period of 508 
days, excepting L. submucida which required 698 days, and the mini¬ 
mum was 394 days. The minimum for L. submucida was 663 days 
with an average of 675.5 days. The averages of the other two-year 
species vary from 411.7 to 461.1 days. 
The three-year grubs averaged from 761.8 to 780.3 days, with a 
maximum of 842 days and a minimum of 735 days in L. crassissima. 
Ecdysis occurs twice before the pupal molt. As observed, the two 
molts previous to pupation in the two-year grubs occur, as a rule, dur¬ 
ing the same season that the egg is hatched, but rarely the second molt 
may be delayed until the following summer. Among the three-year 
grubs, one molt occurs during the season the egg is hatched, and the 
second occurs the following year. To illustrate: two-year grubs 
hatching in 1916 molted twice in 1916 as a general rule, but in a few 
instances the second molt was delayed until 1917. The three-year 
species hatching in 1917 molted once during the summer of 1917 and 
once in 1918. All of the grubs molt at pupation, and generally the 
pupa lies within the cast-off exuvium. 
Pupce 
Besides the data obtained on a large number of reared individuals, 
the records on the length of the pupal stage are augmented by the 
addition of records of a somewhat larger number of specimens reared 
from grubs collected in nature. In general, no striking difference is 
to be noted between the periods of development of those reared and 
those collected, except in the case of specimens of L. crassissima reared 
from the 1916 brood in which the general average of 37.4 days for 56 
pupae was much higher than averages of other seasons or species. 
Table VIII shows a comparison of the time of development in the 
seven species reared since 1916. 
From the table, it can be noticed that the longest period of develop¬ 
ment occurred in the 1916 brood of L. crassissima where a single indi¬ 
vidual required 58 days to mature and in the same brood a minimum 
period of 16 days was required. The averages of the different species 
vary from 21.9 days in the case of L. submucida to 30.5 days in L. 
crassissima. 
Length of Life Cycle 
L. crassissima. —Of 106 individuals reared through the larval stage, 
71 were the so-called two-year grubs and 35 three-year forms. The 
