96 WHITE FLIES INJURIOUS TO CITRUS IN FLORIDA. 
DURATION OF INSTARS. 

Larval instars —By comparing the data in Tables IX and XX it 
will be found that the larve of A. nubifera are slower in maturing 
than those of A. citri. While this difference is not so pronounced 
during the warmer months of the year, the total average number of 
days being 25.9 and 23.1, respectively, during the cooler months it is 
very striking, the total average number of days then being 56.7 for 
A. nubifera, as compared with 30.4 for A. citri. In other respects 
the statements made on the duration of the larval instars for A. citra 
apply to A. nubifera. 
TaBLE XX.—Duration of larval instars of cloudy-winged white fly. 














[ 
Number of days Number of days 
in—  |Sumof in— oa Sum of; 
Speci- EO Giss ertec- | ISpeci- en 
men | Period of growth. tem- || men Period of growth. fone 
No. In- | In-| In- | 7 No. In- | In- | In- | “2 
| star | star} star Na tea star | star] star | Peta 
[| Soe tes Lo 9) $e ee 
| 
1 | June 26-July 19--- 9 |} 6 8 938 33 | Sept. 30-Nov. 20-- 8} 15 28 | 1,322 
2 | June 27-July 20... 6 6 11 942 34 | Sept. 30-Nov. 23..| 11 | 12 31 | 1,401 
3 | June 27-July 21... 8 6 10 979 35 | Sept. 30-Dee. 20..| 11 14 46 | 1,831 
4 | June 27-July 26... 9 7 13 1,179 36 | Sept. 30-Dee. 3... 8 19 37 | 1,670 
5 | June 27-July 19... 9 7 6 902 37 | Sept. 30-Nov. 23..| 8 | 14 32 | 1, 401 
6 | June 27-July 21-.- 8 8 8 979 38 | Sept. 30-Dee. 3...| 11 12 42 | 1,670 
7 | June 27-July 17... 74 6 if 820 39 | Sept. 30-Nov. 27-.. 9 9 40 | 1,513 
8 | June 27-July 19... 5 it 10 902 cL hae ope does =e 8| 14 36 | 1,513 
9 | June 27-July 20...) 7 6 10 942 41 | Sept. 30-Dec.3...| 8] 14 42 | 1,670 
125,55 dove eee 7 6 10 942 || 42) Sept. 30-Nov. 23.. Ly ee! 34 | 15513 
11 | June 27-July 21-.-- 7 6 11 979 || 43 | Sept. 30-Dee.10..| 8 | 15 48 | 1,831 
12 | June 27-July 19... 7 6 9 902 | 44 | Sept. 30-—Dece. 3... 8] 14 42 | 1,670 
13 | June 28-July 27...| 14 8 7 1,179 | 45 | Oct. 2-Dee. 7.....] 10 9 47 | 1,704 
14 | June 28-July 29... 7 6 18} 1,260 || 46 | Oct. 2-Nov. 10.... 7 9 21 | 1,060 
15 | June 28-July 24...) 11 8 Tale 056 47 | Oct. 2-Nov. 30....| 8] 23 26.| 1,524 
16] June 28-July —-. 21-9) | 2 |.22525)2a52-22 || 48 | Oct. 2-Nov.19....| 9] 10 27 | 1,235 
17 | June 28-July 19... 6 6 9 861 AQ") sz 82 dO ee ee dé ||a ales 27 | 1,235 
18 | June 28-July 24... 7 9 10 | 1,056 || 50 | Oct. 2-Nov. 23.. 8 9 33 | 1,332 
19 | June 29-July 29...| 6} 15 9 | 1,222 |) 51 | Oct. 2-Nov. 19.- TN at 28 | 1,235 
20 | June 29-July 24... 7 7 11 1,018 |} 52] Oct. 3-Nov. 27.. Tas 27 | 1,414 
21 | June 29-July 29...| 8 8 14] 1,222 |) 53 | Oct. 3-Dee. 3 10} 17 35 | 1,561 
2, | June 30-July 30...| 8 8 14) 1,229.)| Say" Oct) 3=Dees 7a. 10} 16 40 | 1,662 
23 | June 30-July 29...| 12 7 10 | 1,188.}} 55 | Oct. 3-Dee. 2..-... 10 | 23 28 | 1,536 
24 | Sept. 30-Nov. 1... 5 10 18 912 56 | Oct. 3—Deec. 1..._- 10 15 35 | 1,510 
25 | Sept. 30-Nov. 20..| 8 | 16 28°) “15322 57 | Oct. 3-Dece. 3... 1) 20 33 | 1,561 
26 | Sept. 30-Nov. 30..| 12 12 38 1,593 Gia Boose (0 (0) Sea eee 11 20} 31] 1,561 
7 i ee oie yee 14 15 33 1,593 59 | Oct. 5—Nov. 11.... 9 11} 18] 1,000 
28 | Sept. 30-Dec. 3..-| 12] 23 32} 1,670 60 | Oet. 5-Dee. 10....| 66 died.) RPS pa 
29 | Sept. 30-Nov. 3.-. 8 10 17 963 | | 
; peta th = Be 7 ae 
30'| Sept. 30-Dee.3--.) 8 | 21) 35) 1,670 |Aver-|) pine 26-suly 30...| 8'| 7.8 | 10.1 1,08L7 
31 | Sept. 30-Nov. 30.. Sit ads 40 1,593 age Irsant. 30-Dec. 10 9.1 |14.4 | 33.2 11. 475.6 
32 | Sept. 30-Dec.3...| 8| 14| 42] 1,670 || age. hid oheeg ee aacoats oc ie fe | ade 




Pupal instar.—That little difference exists between the length of 
the pupal stages of the two species of white fly in question is shown 
by a comparison of the data in Tables X and XXI. The minimum 
length of the pupal stage (17 days) will average but a trifle above 
that of A. citri. But the maximum length is so dependent upon the 
seasonal history that a direct comparison is difficult; this subject, 
therefore, is more profitably discussed under the caption of seasonal 
history. What has been said in connection with the maturing of 
specimens of A. citri passing into the pupal stage at practically the 
same time is equally true of the cloudy-winged white fly, A. nubifera, 
