October, ’20] 
WADLEY: SQUASH BUG 
421 
duced only a few eggs, so far as is known, live and go into hibernation. 
Early in September adults begin scattering to seek hibernation quar¬ 
ters, while younger stages develop slowly on account of the increasing 
coolness. After the food plants are killed by frost many starve, while 
others collect on the fruits. Some nymphs mature and adults are 
usually present among the nymphs all fall. These adults, however, 
keep scattering. All remaining nymphs are finally killed by the cold. 
In 1917 a temperature of 14° F. killed all nymphs. The bugs are last 
seen in their summer haunts some time in November. 
Hibernation. When dispersing, squash bugs reach all sorts of 
locations, such as buildings, tree trunks, brush and others. They have 
been found hibernating under boards, under a weed pile, and in bark 
crevices on the under side of a log. From a few to over fifty have been 
found hibernating in one location. Various workers mention hiber¬ 
nation in sheds, under boards, in wood piles, and among stones. At 
Wichita adults of the first, second and perhaps third generations may 
hibernate to appear again as the overwintered generation. 
The shaded blocks in the diagram show the time of year a given 
stage is present while the dotted lines indicate the time it is not present. 
Tabt.e V.— Calendar of Occurrence 
1917 (Kansas) 
1918 (Kansas) 
1919 (Iowa) 
First adult seen. 
May 10 
May 23 
May 30 
June 15 
June 13 
July 6 
July 14 
July 23 
Aug. 19 
Aug. 25 
Early Sept. 
June 19, July 20, 
Aug. 19, 28 
Sept. 11 
First eggs seen. 
Eggs abundant in field. 
June 20 
First nymphs hatched. 
Adults first generation reared. 
Eggs from first generation. 
First nymphs second generation. 
First adults of second generation. 
Eggs from second generation. 
July 12 
July 18 
July 27 
Aug. 20 
July 28 
Aug. 4 
Aug. 17 
Sept. 19 
Nymphs of third generation hatched. . . 
Early Sept. 
June 22, 23, 25, 
July 26, 31, 
Aug. 13, 18 
Sept. 13 
Nov. 20 
Over-wintered females died. 
Last eggs deposited in cages. 
Last adult and nymphs seen in field. 
Sept. 3 
• 
Table VI.— Diagram Showing Stages Present at a Given Time 
Time of Occurrence 
Generation 
Stage 
Hibernation 
May 
June 
July 
Aug. 
Sept. 
Oct. 
Nov. 
Hibernation 
Overwintered- 
Adult . . . 
First. 
First . 
First. 
Second. 
Second. 
Second . 
Third. 
Third. 
Third. 
Egg 
Nymph 
Adult 
Egg 
Nymph 
Adult 
Egg 
Nymph 
Adult 
