Dec. 1, 1925 
The TJse of Vacuum for Insect Control 
1037 
As indicated by the data of Table I, an exposure of 24 hours was 
fatal to nearly all the insects treated. Larvae of the dermestid 
beetles proved quite resistant, only 50 per cent of those of Anihrenus * 
fasciatus and Attagenus piceus, and none of Trogoderma tarsale being 
killed. The eggs of the webbing clothes moth, Tineola biselliella, 
and the larvae of both this clothes moth and the case-making clothes 
moth, Tinea pellionella, showed much resistance. 
A two-day exposure killed all specimens treated with the exception 
of the eggs of Tineola biselliella , of which only 40 per cent were killed, 
and the larvae of Trogoderma tarsale , of which only 20 per cent were 
killed. A four-day exposure killed all stages of all insects. 
EXPERIMENT NO. 2 
In the second experiment the same species of insect pests were 
used, except that Gnathocerus cornutus and G. maxillosus displaced 
Sitophilus granarius. A 29-inch vacuum was obtained and the 
vacuum was not allowed to fall below 28 inches at any time during 
the course of the experiment. The barometer reading was 29.3 
inches and the temperature for the period varied between 60° and 
70° F. 
As shown in Table II, a large percentage of the insects treated were 
killed by a seven-hour exposure. Adults of all species were killed, 
but the larvae of Tenebrio, Tineola, Tinea, and Trogoderma were 
apparently but little affected by the seven-hour exposure, whereas 
70 per cent of larvae of Ephestia and 80 per cent of larvae of Plodia 
were killed. A one-day exposure to this vacuum killed all stages of 
all insects experimented with, with the exception of the larvae of 
Trogoderma tarsale , 50 per cent only of which were killed, and the 
eggs of Tineola biselliella , 90 per cent of which survived. 
Table II .—Effect of vacuum varying from 28 to 29 inches upon insects in bell jar 
of 825 cubic inches capacity 
Insect 
Killed in seven hours 
Killed in one day 
Larvae 
Pupae 
Adults 
Eggs 
Larvae 
Pupae 
Adults 
Alphitobius piceus Oliv 
P. ct. 
P. ct. 
P. ct. 
100 
P. ct. 
P. ct. 
P. ct. 
P.ct. 
100 
Anthrenus fasciatus Hbst 
100 
100 
100 
100 
Attagenus piceus Oliv 
100 
155 
100 
100 
100 
100 
Cryptolestes pusillus Scbon 
100 
100 
100 
100 
Darmestes vnlpinns Fab 
100 
100 
100 
100 
Ephestia kuehniella Zell 
70 
100 
100 
100 
100 
Gn at.hneerns enrnnt.ns Fab 
100 
100 
Gnathocerus maxillosus Fab 
100 
100 
TsTeernhia rnfipes Dp. Geer 
100 
100 
Ory^aepbilus surina TnfiTi sis L 
100 
100 
Plodia interpunctella Hbn 
80 
100 
100 
100 
100 
Silvanns gem ell at, ns Dnv 
100 
100 
Ri't.nnhilns nrvza T. 
100 
100 
Tp.nAhrin nhsenrns Fah 
0 
100 
100 
A VllVUilU UUlJVUiUu JL CA — w-.---— — — — 
r PpTipbrmHp« mntirit.n'nipiis T. 
100 
100 
Tineola biselliella Hum 
0 
10 
100 
100 
100 
TinAfl ■neTlirmella T. 
0 
100 
A. iilVCI* pCUli-VilVlK* JU — — — -— — - - 
Tribolinm confusum Ouv 
100 
100 
TriVinlinw forrnofinpnm Fab 
100 
100 
tarsale Melsh 
0 
50 
