1036 
Journal of Agricultural Research 
Vol. XXVIII, No. 10 
An examination of the larvae chopped out on December 17 showed that they 
were all apparently dead, although some were still white and soft. The pieces 
that were tagged and placed in the kiln for future observation were examined 
December 14 and did not show any signs of larval activity. A final examina¬ 
tion of this lot was made January 10, which verified the foregoing preliminary 
results (PI. 1, B). 
LOT II 
Lot II was held for a longer time at every 10° interval than Lot I. It was not 
deemed necessary to subject any samples to 160° F. The four pieces of oak 
were included in this lot. All of the samples were placed in the kiln and their 
temperature raised at once to the initial temperature without previously bring¬ 
ing all parts of the wood to kiln temperature, as was done with Lot I. At 8.30 
a. m., December 13, the lot was placed in the kiln at 100° F. From 8.30 to 9 
a. m. the temperature advanced to 130°, where it was held for two and one- 
half hours, or one hour longer than in the case of the previous lot. From 130° 
onward, pieces were removed at every 10° interval until the temperature 
reached 150°. The maximum thermometer showed that during the work on 
Lot II the indication of the recording thermometer was 2° too low. 
Table II.— Experiments to determine temperatures fatal to Lyctus planicollis by 
steaming infested ash and oak lumber in a kiln. Lot II 
Sam¬ 
ple 
No.® 
Size 
Tempera¬ 
ture and 
time held 
Time 
held at 
accumu¬ 
lated 
tempera¬ 
ture 
starting 
at 130° F. 
Humid¬ 
ity 
Propor¬ 
tion of 
sap- 
wood 
Number 
of piles 
of frass 
noted 
before 
steam¬ 
ing 
Larvae 
chopped out 
immediately 
after steaming- 
number and 
condition 
Final examina¬ 
tion, Jan. 10, 
4 weeks after 
steaming. Piles 
of frass noted; 
larvae chopped 
out where results 
were doubtful b 
Inches. 
°F. 
Hours . 
Hours. 
Per cent. 
Per cent. 
1 
1X12X18 
130 
2* 
2i 
100 
25 
(*) 
No signs of ac¬ 
tivity. 
2 
1X12X18 
130 
21 
2i 
100 
25 
2 
Do. 
3 
1X12X18 
130 
24 
4 
100 
100 
( c ) 
Do. 
4 
1X12X18 
130 
21 
2i 
100 
100 
( c ) 
Do. 
5 
1X12X18 
140 
2i 
5 
100 
100 
2 
3 larvae (1 
Do. 
white). 
6 
1X12X18 
140 
24 
5 
100 
100 
2 
Do. 
7 
1X12X18 
14a 
2§ 
5 
100 
100 
2 
Do. 
8 
1X12X18 
140 
2$ 
5 
100 
100 
1 
Do. 
9 
1X12X18 
150 
2? 
7* 
100 
100 
1 
Do. 
10 
1X12X18 
150 
2 } 
74 
100 
100 
(0 
Do. 
11 
1X12X18 
150 
2} 
7 \ 
100 
40 
1 
Do. 
12 
1X12X18 
150 
2* 
74 
100 
100 
(*) 
Do. 
13 
2X12X18 
130 
4 
24 
100 
30 
2 
Do. 
14 
2X12X18 
130 
2\ 
24 
100 
30 
2 
Do. 
15 
2X12X18 
140 
2* 
5 
100 
25 
3 
Do. 
16 
2X12X18 
140 
2£ 
5 
100 
25 
2 
Do. 
17 
2X12X18 
150 
24 
74 
100 
30 
2 
Do. 
18 
2X12X18 
150 
2$ 
74 
100 
10 
5 
Do. 
19 
1*X12X18 
130 
2 4 
24 
100 
3 
( e ) 
Do. 
20 
UX12X18 
140 
2} 
5 
100 
5 
(0 
Do. 
21 
lfX12X18 
150 
24 
74 
100 
3 
(<0 
Do. 
22 
1JX12X18 
150 
2} 
74 
100 
3 
(‘) 
Do. 
® Nos. 1-18 are ash; Nos. 19-22 are oak. 
6 Examined by C. C. Shackford December 15, 17, and 21 and January 3; checked by R. A. St. George 
on final examination. 
c No piles of frass noted, but all samples infested. 
An examination of the larvae chopped out on December 17 showed that they 
were all dead, although some were still white and soft. The tagged pieces were 
examined with those of Lot I and the results were found to be the same. A final 
examination of this lot on January 10 showed that all the insects had been 
killed and the damage checked (PI. 1, B). 
