THE CLOUDY-WINGED WHITE FLY: SEASONAL HISTORY. 101 
number of days required for development, shown especially by com- 
parisons of lots 1, 3, 6, and 7 of Table XXIII and lots 4, 5, 14,-and 
15 of Table XV, is not the result of chance circumstances, but actually 
the result of slower general development under identical conditions. 
This fact is perhaps more forcibly brought out by the data in Table 
XXIV: 
TaBLE XXIV.—Late of development of A. citri and A. nubifera compared. 









Citri. Nubifera. 
Date. | | 
Instar | Instar | Instar | Instar | Instar | Instar | Instar | Instar 
ile ay | 3. 4. ats Le 3. 4. 
| P.ct. | P. ct. | Pct Pacte WLP. ch EP chee. ch \eack 
Uileg 88.3 | 0) 0 77.9 22.1 | 0 | 0 
2.1 |, 82.7 | 15.2 0 6.9} 92.1 1.0) 0 
ail 10.5 89.8 0 1.4 30.8 67.8 0 
0 4.8 | 86.1 -0 0 8.1 91.1 0.8 
0 2.9] 20.6 76.7 Oe 5.9 62.2 31.9 
0 0 | 6.1 93.9 0 -8 2205 Osis 
0 0 | 0 100.0 0 0 14.9 85.1 
98.4 1.6 | ORI SCS 99.6 4 0 0 
| 8.0 92.0 0 | 0 35.8 64.2 0 0 
CC ee a eee Ptr). MBgee | h 46.0. O's W2e9h] SOG ON Ee: 1d 0 
LE Ss CE ene ae ei Glee aaa 90. 7 0 PAIN SESS MI) 0 
(OVE HEi Set Shi | eee eet eae ce 0 224) LTS 4.4 1.8 20.9 75.4 1.8 
Mower berets ses seen ene wep ee 0 | 9 | 1.9 80.3 0 3.3 90.0 6.6 
Becenihens: - asses. J. so.582 Beles! 0 0 | 1.9 97.1 0 0; 28.2 71.8 
IDB aD E RS 5 ae ee eee 0) 0 0} 98.1 0 On. 1257 87.3 
Wecembendmecceet caress ee sok 0 | 0 | 0 100.0 0 (Nit EES 95.8 
IDV pPtel ie Ape cae Sena See Ser eee ase 0 | 0 0) 100.0 0 0 | 0 100.0 



In this table is shown the corresponding progress of growth of 
both species on various dates after egg deposition. The data con- 
cerning development during July refer to larve hatching from eggs 
laid on June 16, 1909, and that during October, November, and 
December to larve hatching from eggs deposited on September 18, 
1909. For these records, leaves on the same shoot were chosen for 
deposition of the eggs of each species; hence both species were subject 
to identical climatic and nutritive conditions. 
A study of the data in Tables X and XXI will also prove that the 
same statements made for A. citri concerning the equalizing effect 
of winter on the length of the pupal stage for wintering-over pup 
are equally true for A. nubifera. The data show at a glance that 
eggs deposited in late October are capable of producing adults the 
following spring as early or even earlier than eggs deposited a month 
or, as sometimes occurs, five months earlier. 
SEASONAL HISTORY. 
GENERATIONS OF THE CLOUDY-WINGED WHITE FLy. 
Aside from the fact that the adults of this species have never been 
seen by the authors on wing during January and early February, as 
have those of A. citri, there being therefore no winter generation 
