PEOGEESS EEPOET OK" THE EUBOPEAK" COEN BOBEK 
131 
for if the ice melts slowly and the current bearing it is swift enough, 
it may be carried considerable distances before being thrown on 
shore or melted. Free cornstalks tend to become saturated with 
water and sink after a varying length 'of time in water, so that 
although great numbers of stalks may be carried into a body of 
water like Lake Erie, many may sink before reaching another shore, 
and although some of these may eventually reach shore, for example 
by the movement of water during storms, the possibility is that 
as a usual thing most of the larvae contained in such stalks perish. 
Cornstalks would be more likely to be swept along in the rivers 
where quicker currents are found, particularly in the spring when 
many rivers are swollen and more active, than in large bodies of 
water such as lakes, where cornstalks might sink before being carried 
to another shore. 
SURVIVAL OF LARVAE AND PUPAE IN WATER 
In order to determine the survival of larvae or pupae when con- 
tained in floating or submerged plant material, a series of experi- 
ments were carried on in New England in both fresh and salt (sea) 
water. The reaction to water of free larvae and pupae was also 
investigated. The results of these experiments are shown in Table 42. 
Table 42. — Survival of Pyrausta nuMlaMs larvae and pupae in water 
Materials 
Date 
placed in 
water 
(1920) 
Date 
removed 
(1920) 
Du- 
Num- 
ra- 
ber 
tion 
of 
pe ; 
speci- 
nod 
mens 
Days 
28 
173 
43 
89 
62 
98 
36 
55 
37 
212 
62 
42 
2 
26 
5 
23 
9 
22 
14 
5 
Hours 
42 
10 
96 
10 
120 
10 
18 
8 
42 
6 
67 
6 
216 
59 
163 
59 
48 
100 
24 
10 
48 
10 
65 
10 
89 
10 
Per cent 
alive 
Remarks 
Cornstalks submerged in fresh 
water. Overwintering lar- 
vae. 
Do 
Do 
Cornstalks floating in fresh 
water. Overwintering lar- 
vae. 
Cornstalks floating in sea 
water. Overwintering lar- 
Do. 
Free larvae submerged in fresh 
water in wire-screen cages. 
Overwintering larvae. 
Cornstalks submerged in fresh 
water in wire-screen cages. 
First-generation larvae. 
Cornstalks submerged in sea 
water in wire-screen cage. 
Firsts-generation larvae. 
Cornstalks floating in fresh 
water inclosed by screen cyl- 
inder. First -generation lar- 
vae. 
Feb. 
Mar. 
—do. 
Mar. 
Mar. 15 
...do. 
May 
..do. 
..do. 
..do. 
July 
'do. 
..do. 
'Aug. 
..do. 
..do. 
...do. 
Aug. 
Same as above in sea water- 
Free larvae submerged in fresh 
Mar. 
Apr. 21 
May 10 
Apr. 21 
Apr. 21 
May 16 
May 6 
May 9 
May 13 
May 18 
July 31 
Aug. 2 
Aug. 3 
Aug. 6 
Aug. 7 
Aug. 8 
Aug. 14 
Aug. 9 
July 31 Aug. 2 
July 28 July 29 
water in wire-screen cages. \{"^ 1 J^w q? 
First-generation larvae. j(-£° j JJjjJ d J 
1.1 
None. 
3.6 
1.4 
None. 
88.5 
95.9 
22.7 
40 
20 
None. 
None. 
(A) None. 
(B) 16. 6 
(C) None. 
(D) None. 
11.9 
None. 
(A) 60 
(B) 10 
None. 
None. 
67 larvae pupated; 
duced moths. 
pro- 
Larva died 16 days later. 
1 surviving larva pupated 
and produced a moth. 
3 surviving larvae died 15, 
37, and 41 days later. 
Majority of surviving lar- 
vae pupated and pro- 
duced moths. 
1 larva pupated and pro- 
duced a moth. 
In (B) 2 larvae pupated in 
stalks. Did not produce 
moths. 1 larva pupated 
afterwards and produced 
a moth. No pupation in 
(D). 
5 larvae pupated in floating 
stalks but did not pro- 
duce moths. Three sur- 
viving larvae pupated aft- 
wards and produced 
moths. 
In (A) 5 surviving larvee 
pupated and produced 
moths. Same in (B) . 
