Dec. is, 1925 Observations on a Cotton Insect New to the United States 1145 
S to adult, was only 31. These 31 records are therefore considered 
ividually. 
The total length of time occupied by these 31 fifth-stage records 
was 564 days, giving an individual average of 18.2 days each. The 
individual variation was from 10 to 29 days. Since, however, the 
first adult reared from the egg in the cages appeared on October 7, 
1923, and all of the remainder were reared during the months of 
October, November, and December, 1923, it is evident that their 
life-history periods were longer than they would have been during 
the hotter months of midsummer. 
TOTAL PERIOD OF DEVELOPMENT 
From the data presented it is apparent that great variation exists 
between the total length of time required for development during 
the months of midsummer and those of fall and winter when the 
periods of development are considerably extended because of lower 
temperatures. Table I shows this more clearly, and presents the 
information in a more concise form. 
Table I .—Developmental periods of Dysdercus obscuratus at different seasons 
Stage 
Midsum¬ 
mer 
period 
Fall 
period 
Winter 
period 
Total 
number 
of 
records 
Total 
number 
of 
days 
Average 
period of 
develop¬ 
ment 
Tnfflihation 
Days 
5 
Days 
8 
Days 
12 to 17 
26 
Days 
7.85 
First stage___ 
3 
5 
10 to 13 
21 
132 
6.29 
Second stage--- 
4 
6 
11 to 13 
13 
109 
8.39 
Third stage- 
5 
9 
15 to 18 
9 
85 
9.44 
Fourth stage--- 
5 
7 
15 to 19 
11 
no 
10. OC 
Fifth stage--- 
10 
20 
24 to 28 
31 
564 
18.20 
Total development... 
32 
55 
87 to 108 
111 
1,000 
60.17 
THE ADULT 
The adults are brightly colored, slightly more than one-half inch 
in length, the antennae adding to this about three-eighths of an inch 
(fig. 2, B). The head is coral red, with a narrow white band between 
the head and thorax. The thorax contains a transverse band of 
coral red, followed by a narrow yellow band, with a transverse black 
ridge at the base of the wings. The predominating colors of the 
wings are black and yellow, with faint white margins. The colora¬ 
tion of the wings varies considerably, irrespective of sex, some adults 
having much more yellow than black, others having nearly black 
wings with little yellow showing. The legs and antennae are orange 
at the base, with black extremities. The abdomen is bright red 
dorsally, with white lines between the segments. Ventrally the 
abdomen is white with a bluish tinge, and has bright red lines be¬ 
tween the segments. 
It is rather difficult to distinguish the sexes from each other. 
Usually the female is slightly larger than the male, and the abdomen 
is larger and stouter. The most easily distinguished sexual charac¬ 
ter is the wider red bands across the ventral surface of the abdomen 
of the male, particularly the last three segments. 
