July 7, 1923 
Mediterranean Fruit Fly in Hawaii 
5 
Table II .—Percentage of parasitism of laruce of Ceratitis capitata in Hawaii in IQIQ and 
IQ20 — Continued 
Host fruit. 
Month. 
Number of 
larva; 
emerging 
during first 
2 to 6 days. 
Percentage of parasitism. 
Opius 
humilis. 
Diachasma 
tryoni. 
Diachasma 
fullawayi. 
Tetrastickus 
giffardianus. 
Total. 
1919 
1920 
1919 
1920 
1919 
1920 
1919 
1920 
1919 
1920 
1919 
! 1920 
i 
Chinese orange.. 
Guava. 
Jan... 
382 
292 
129 
292 
207 
103 
279 
159 
7-9 
3 - 1 
20.9 
16.8 
4* *3 
14.6 
4 - 7 
8.2 
1.8 
•7 
.8 
2.4 
12.1 
0.8 
i -7 
1.6 
1*7 
3*4 
0-5 
1.0 
3*1 
2-7 
11.1 
1-0 
3*6 
7.6 
11.0 
6*5 
26.4 
23.6 
30.9 
15*6 
1 23.0 
20.8 
Feb... 
Mar... 
Apr... 
May... 
June.. 
July... 
Aug... 
705 
440 
735 
350 
304 
60 
0.6 
1.6 
2.0 
1.4 
•3 
10.6 
6.6 
7-9 
11.4 
6.9 
10.0 
1.0 
1.4 
. 1 
1.8 
.8 
5*2 
10.0 
14.0 
9.6 
10. 8 
12.8 
12.4 
2 3*3 
10.4 
4-4 
3*3 
4*3 
.6 
Sept.. 
Oct... 
Nov... 
Dec... 
Jan... 
61 
53 
244 
245 
3-3 
3 - 8 
2.0 
4 - 5 
3-3 
'”.*8 
I. 2 
3*3 
i.*6 
4. r 
9*9 
3*8 
7*7 
11.8 
84 
368 
147 
1,258 
I>i 39 
I 5 i 
40 
3-6 
2. 2 
2.7 
8.7 
10.0 
n -3 
5 -o 
1. 2 
9*5 
4-8 
5*9 
13*8 
2.0 
3*6 
20.1 
4*8 
5*2 
3*2 
4-0 
5 *o 
3*3 
2.0 
20. 2 
5*4 
12. 2 
7*9 
24.7 
49 * 7 
55 *o 
28.6 
37*2 
24*5 
27.7 
5 i *7 
67.0 
65.0 
Loquat. 
Feb... 
Mar... 
Apr... 
May... 
June.. 
July... 
Aug... 
Sept.. 
Oct... 
Nov... 
Dec. .. 
Feb... 
July... 
Aug... 
Feb... 
140 
I>2 33 
679 
i>ii 5 
949 
580 
292 
141 
93 
90 
237 
498 
179 
43 
2.9 
1.9 
1.4 
4.0 
23-3 
27-5 
13*4 
22.4 
7*9 
8.5 
2. 2 
1.4 
•5 
•3 
.6 
1.1 
•7 
21.6 
14-9 
14.0 
1.0 
ii *5 
13*8 
12.5 
18.6 
31*8 
8*5 
9*7 
13*3 
12. 2 
•4 
5*7 
7*4 
35 *i 
42.1 
3 i *5 
44*1 
61. 6 
3 i *9 
25*9 
13-3 
29.4 
18.0 j 
1.2 ! 
7.0 
. 2 
4-5 
2.4 
•3 
251 
2.0 
4.8 
2.0 
21.9 
30.7 
184 
919 
338 
277 
1.6 
•5 
4.9 
14.8 
14.2 
1.8 
16.3 
14.8 
13*0 
4*3 
22.3 
10.9 
37 *o 
19.1 
45-1 
41.0 
64. 2 
25. 2 
8.8 
2.8 
.6 
3*8 
ir. 2 
.6 
7.0 
4.6 
3*6 
Noronhia. 
Orange. 
21 
330 
142 
4.8 
.6 
4*8 
3 *o 
2.8 
4-8 
7.6 
7*7 
14.4 
12.4 
10.5 
Mar... 
Apr... 
May... 
Sept.. 
Oct... 
Nov... 
Dec... 
21 
24 
5 
42 
68 
26 
8 
. 
. 
1. 2 
. 
. 
. 
2.4 
4*4 
ii *5 
2*4 
8.8 
ii *5 
4.4 
333 
. 
•3 
. 
2.4 
. 
1. 2 
20.4 
1 
24*3 
Tables III and IV record the work of each parasite in all fruits collected 
over monthly and yearly periods. In Table III, the percentages of 
parasitism by Diachasma fullawayi for 1919 are typical of those for 
previous years. A comparison of those figures with percentages for 
1920 in the adjacent column on the right again reveals the increase in 
the effectiveness of this parasite. In two months of 1920, January and 
August, its work exceeds that of any one of the other three parasites, 
and in six other months it was second in effectiveness. As indicated in a 
previous publication, 4 the ability of D . tryoni and fullawayi to destroy 
Opius humilis when they occur in the same host larva influences the 
amount of parasitism by O. humilis to a great extent. O. humilis has 
always been more abundant during the cooler months of the year, when 
the two species of Diachasma are less active and have a tendency to 
hibernate; and it decreases greatly in numbers during the warmer 
months, when it must contend with maximum numbers of Diachasma. 
In records of parasitism for 1916 5 the effectiveness of O. humilis during 
five months out of the year was greater than that of both species of 
4 Pemberton, C. E., and Willard, H. F. interrelations of fruit-fly parasites in Hawaii. In 
Jour. Agr. Research, v. 12, no. 5, p. 285-296, pi. 10-13. 1918. 
• Pemberton, C. E., and Willard, H. F. fruit-fly parasitism in Hawaii during 1916. In Jour. Agr. 
Research, v. 12, no. 2, p. 103-108. 1918. 
