12 BULLETIN 554, U. S. DEPARTMENT OF AGRICULTURE. 
on the average, 21 days. (See Table V.) Under natural bog con- 
ditions, following the drawing of the winter flowage about May 10, 
it is very likely that the pupal period is several days shorter im 
duration than as stated. The pupa is always found with the head 
pointing toward the neck of the cocoon, eventually permitting the 
easy emergence of the moth. 
TABLE V.—Length of pupa stage of the cranberry girdler, Pemberton, N. J.. 
1914. 
| Date | Date 
. +, | Date of Length of . Date of Length of 
E No. - ul E ; : 
xperiment No [pupation. seed stage. xperiment No pupation. | awa Stage. 
See a A es | 
| Days. Days. 
ja Ss ee es BARS FERS | Apr. 281 (2) PSEA. EES. OEae ek ee Apr. 30 (2)1 3], $3 Ee 
11 OR ne | Apr. 291) May 11 AOU ALO ee ers Are May 2} (2) xg al ee oe 
Fay feos Pre: |_..do....| May 15 16° (Ms ee eb Te |...do....| May 18 | 16 
hoc nee eel ee do....| May 18 TUM | Oe ee eno do 16 
iy £23) Meee ee AeA eee eee do....| May 20 21 MiBE Pee eee May 7) June 5 29 
Uae A, Sete peed Bee do....| May 27 23 ota aern epee case May 23 | June 13 21 
1ST SA 9 5 es Sere BG Se | Fk oe do....| May 29 SOUIMSS SOS Fe May 29 | June 17 19 
Bee ee. cadets sl Apr. 30 |...do 29 WalG eee eee eee ree es | 19 
Average days, 21.15. 1 Approximate. 2 Died. 
NATURAL ENEMIES. 
Among the parasites there appear to be very few which attack the 
cranberry girdler. No parasites were obtained in the rearing cages, 
but occasionally when opening cocoons the remnants of a parasite 
in one stage or another were found. From such findings two species 
of Ichneumonide were secured. The habit of concealed feeding of 
the girdler larve must be a great protection against parasitic enemies, 
and the winter flowing of the bogs probably also tends to lessen the 
activities of parasites. 
In areas of severe girdler infestation spiders have been found to 
be very abundant as well as have various species of ground beetles. 
Among the ground beetles Harpalus caliginosus Fab. and Anisodac- 
tylus harrisit Lec. have been collected. 
Very often an area of vines infested with girdler larve will be 
invaded by field mice, and the burrows just beneath the surface will 
run throughout the entire section. While mice occasionally cut off 
cranberry vines which are in the line of a runway, they should be 
classed as minor pests of the cranberry industry. The work of mice 
may be recognized by the diagonal cut of the severed vine and the 
furrows made across the end by their teeth. It is thought, however, 
that the mice search for girdler larve and are instrumental in reduc- 
ing large infestations. They nest in roundish houses built of grasses 
above the level of winter flowage. 
Among the birds which prey on insects the swallows are perhaps 
the most useful in capturing girdler moths. At Howardville, N. J., 
a swallow followed the writer the length of one of the bogs, and as 
