24 BULLETIN 737, U. S. DEPARTMENT OF AGRICULTURE. 
In experiments made by the writer at Tampa, Fla., a total of 567 
eggs was obtained from 21 females, or an average of 27 eggs each. 
The longest period of oviposition was 11 days. The largest num- 
ber of eggs found in any one of 64 females dissected by Mr. S. E. 
Crumb on August 3, 1911, was 22. 
At Clarksville, Tenn., the average number of eggs laid per female 
during July, August, and September was 32, as shown by 63 separate 
records. The longest period of oviposition was 21 days. Approxi- 
mately 66 per cent of the eggs were laid during the first six days 
after mating was observed. Each pair of beetles was kept in a 
shell vial containing leaf tobacco. 
INFERTILE EGGS. 
Occasionally a female was found to lay infertile eggs, even after 
mating. No eggs were obtained from unmated females. In one 
series of experiments, of a total of 182 eggs obtained from 24 different 
females found in copula, 25 eggs, or 13.7 per cent, were infertile. 
The eggs were deposited on leaf tobacco and kept at a temperature 
of about 84° F., the daily variation being about 5°. This infer- 
tility probably is much above the average, as hatching in many 
other lots was almost perfect. The number of infertile eggs in 11 
different lots, containing in all 773 eggs, was 30, or approximately 
5.8 per cent. 
LENGTH OF DIFFERENT STAGES IN DEVELOPMENT OF INDIVIDUAL BEETLES. 
The following records from life-history studies made at Rich- 
mond, Va., show the time required for each period of development 
of different beetles from the egg to the adult. 
TasleE III.—Length of different stages in development of individual tobacco 
beetles (Lasioderma serricorne). Richmond, Va., 1914. 
Larva Larva Adult 
Record No. Ae aoe Hatched—| formed pu- Z ae pe left 
cell— pated— P cell— 
PAR ae eee Se Sete eee SAO Ge at Md Le July 1] July 8} Aug. 17] Aug. 22] Aug. 29] Sept. 6 
A galas 8 ei We ee Oe eS ee Ee, Sei 8 8 Re Ee doxzes4t2-d0 Aug. 19} Aug. 23} Sept. 1| Sept. 5 
2B ppt ae Neth oa 5 9S INE ale 5 Ot Seles ORGS e July 5} July 12) Aug. 22| Aug. 28) Sept. 4| Sept. 9 
LY Rae A SERRE ee Sere’ Se eee ere SL mea June 1{| June 7) July 18] July 22] July 29| Aug. 2 
Pye WD be, SENN SOS Be 2a Ee ee ee June 18 | June 25 July 30] Aug. 3); Aug. 9} Aug. 16 
= Eggs Egg to Egg to 
Record No. Mated—] jaiq Food. eatios egg. 
Days. Days. 
I a 2a ee eS ORE RRR OP RE AA EGE! aM yams Be Sept. 9 | Sept. 11 | Tobacco........-... 59 72 
DS ee he Rae Ts ee Oe RE CRT SOE Sept. 7 | Sept. 10]..... dome ee sae: 62 71 
Spat ao ait ap AN eke Pa eee le Smee Sept. 10 | Sept. 17 }..... dos 2a ee 61 74 
MIR Se eS: SRE CSRS TE 8S Sees ee IRAE SEGA PANIES) 2s re a ee eae ie 58 69 
