OF WASHINGTON. 115 
they were left for a longer period, and the cones pretty generally evapo- 
rated. In December this was noticed and the boxes were again over- 
hauled, and it was found that a very general development of larvae had 
begun all of them Trogoderma and none of them more than 2-3 mm. in 
length most of them apparently just hatched. The entire collection was 
then overhauled and an occasional Anthrenus larva was found, but no 
other Trogoderma, even in the most exposed boxes. 
I conclude from this that the collection when received was pretty gen- 
erally infested, and that there were eggs everywhere, ready to develop; 
some had begun to develop, and these were destroyed by the use of the 
Bisulphide of Carbon, which also served to check development of the 
eggs. The boxes were quite large, and two large cones were put in each; 
they were also quite secure, and the atmosphere in them was fully impreg- 
nated with the odor of naphthaline. Throughout the summer, when under 
ordinary circumstances they would have developed, the eggs remained 
dormant, but after the naphthaline had evaporated completely, development 
began. I might add here that Trogoderma is an exceedingly rare pest in 
New York, and not common in Washington, further south it seems to 
replace Anthrenus. For all these pests, when out of the egg, Bisulphide 
of Carbon is a sovereign remedy, except where they are burrowing in large 
Coleoptera and Lepidoptera. I have repeatedly soaked large Bombycids 
with chloroform or bisulphide, and a week later found them still infested. 
I worked for a month over some large Lucanids {Proculejus} and finally 
separated the parts so that I could fill the body cavity with chloroform. 
In one case, which was somewhat exposed and contained odd material 01 
little value, I found a specimen destroyed by Microgaster a rare parasite 
for Anthrenus. How they got at this box it is rather difficult to explain, 
since it was tight enough to prevent the entrance of the insect. 
As a rule Anthrenus can hardly be considered fastidious, but occasion- 
ally they manifest color preferences. In one specimen of Grapta inter- 
rogationis the black spots bordering on the costa were neatly cut out, no 
other portion of the wing being touched. Its career was suddenly cut 
short before it had quite finished one wing, and I now regret that I did not 
allow it to continue its work to note whether it would have attacked the 
other wing in the same manner. 
I have noticed also that boxes on the lower tier of shelves are very much 
more liable to attack than those on upper tiers, and this leads me to believe 
that the parent beetle will deposit eggs outside of the boxes or on the floor 
of the cases, and the young larvae will work their way into the smallest 
crevices. It seems difficult otherwise to account for isolated larvae in boxes 
containing only old insects. 
Finally I find the danger of infection comparatively greater at Washing- 
ton than in New York principally because the warm season begins earlier 
and lasts longer, increasing the chances of infection. I find, too, that the 
only real chance of safety consists in constant examination, tight boxes 
and a free use of chloroform or Bisulphide of Carbon. 
