8 
BULLETIN 254, 17. S. DEPARTMENT OF AGRICULTURE. 
From the notes made by Mr. V. L. Wildermuth at Tempo, Ariz., 
during February and March, 1913, the length of the egg stage is 
shown in Table III to be practically the same as found by the writer 
for those months. 
Table III. — Length of egg stage of the sharp-headed grain leafhopper, Tempe, Ariz., 
February and March, 1913. 
Date of oviposition. 
Date of Length of 
hatching. egg stage. 
Feb. 21 
Mar. 29 
Mar. 18 
Mar. 22 
Mar. 25 
Days. 
36 
21 
23 
26 
Feb. 25 
Feb. 27 
Feb. 27 
Average 
26.5 
LENGTH OF NYMPHAL STAGE. 
As with the egg stage, the length of the nymphal stage varies with 
the temperature. Prof. Osborn's observations in Iowa show that the 
nymphal stages extend over from early spring until the latter part 
of June and from the second week in August until nearly winter. 
Where the temperatures are higher and the summer season more 
prolonged the length is considerably shortened. The observations 
at Tempe, Ariz., show that the average length varies from 20 to 51 
days, according to the temperature. Table IV gives the length of 
the nymphal stage of each of the six generations and the length 
of each instar. 
Table IV. — Length of nymphal stage of the sharp-headed grain leafhopper. Tempe, 
Ariz., 1914. 
FIRST 
SPRING GENERATION, MARCH, 
APRIL, a 
LND 
MAY, 1914. 
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Days. 
Days. 
Days. 
Days. 
Days. 
Days. 
Mar. 4 
Mar. 14 
10 
Mar. 25 
11 
Apr. 4 
Mar. 30 
10 
Apr. 13 
9 
Apr. 23 
10 
50 
Do.... 
Mar. 10 
6 
Mar. 18 
8 
12 
Apr. 8 
9 
Apr. 20 
12 
47 
Mar. 10 
Mar. 23 
13 
Apr. 2 
10 
Apr. 8 
6 
Apr. 14 
6 
Apr. 23 
9 
44 
Do.... 
Mar. 19 
9 
Mar. 28 
9 
Apr. 6 
9 
Apr. 13 
7 
Apr. 21 
8 
42 
Mar. 8 
Mar. 17 
9 
Apr. 1 
15 
...<Io 
5 
Apr. 11 
5 
Apr. 20 
9 
43 
Mar. 11 
Mar. 10 
Mar. 19 
Mar. 24 
8 
14 
...do 
40 
46 
Apr. 3 
10 
At>r. 8 
5 
Apr. 14 
6 
Apr. 25 
ii 
Mar. 12 
Mar. 26 
14 
Apr. 7 
12 
Apr. 16 
9 
Apr. 27 
45 
Mar. 8 
Mar. 22 
14 
Apr. 2 
11 
Apr. 7 
5 
Apr. 17 
10 
Apr. 2S 
u 
51 
Mar. 10 
Mar. 25 
15 
Apr. 6 
12 
Apr. 11 
5 
Apr. 20 
9 
Apr. 30 
10 
51 
Mar. 20 
Mar. 21 
1 
Apr. 1 
11 
Apr. 6 
5 
Apr. 14 
8 
...do 
16 
41 
Mar. 6 
Mar. 19 
13 
Apr. 3 
15 
Apr. 13 
10 
Apr. 17 
4 
Mav 2 
15 
57 
Mar. 12 
Mar. 27 
15 
Apr. 8 
12 
...do 
5 
Apr. 20 
7 
May 5 
15 
54 
Mar. 7 
Mar. 19 
12 
Ar>r. 1 
13 
Apr. 7 
6 
...do 
13 
Mav 6 
16 
60 
Mar. 20 
Apr. 6 
17 
Apr. 13 
7 
Apr. 16 
3 
Apr. 23 
7 
May 7 
14 
48 
Mar. 8 
Mar. 27 
19 
Apr. 6 
10 
Apr. 13 
7 
Apr. 20 
7 ...do 
17 
60 
Mar. 20 
Apr. 4 
15 
Apr. 11 
/ 
Apr. 16 
5 
Apr. 21 
5 : May 8 
17 
49 
Do.... 
Apr. 6 
17 
Apr. 13 
7 
Apr. 17 
4 
Apr. 28 
11 May 9 
11 
50 
Mar. 21 
Apr. 2 
12 
Apr. 8 
6 
Apr. 13 
5 
Apr. 20 
7 ...do 
19- 
49 
Mar. 20 
Apr. 4 
15 
...do 
4 
...do 
5 
Apr. 29 
16 1 May 11 
12 
52 
Mar. 18 
Mar. 10 
Mar. 30 
12 
Apr. 6 
Apr. 4 
7 
Apr. 11 
...do 
5 
7 
...do 
54 
63 
Apr. 20 
9 I May 12 
22 
Mar. 20 
Apr. 2 
13 
Apr. 6 
4 
Apr. 14 
8 
Apr. 24 
10 May 15 
21 
56 
Av 
erage 1 
13.2 
9.5 
6.4 
8.2 
13.8 
50.1 
Total of averages of instars, 51.1 days. 
