306 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
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A. M. 
Crawled about within the dust ring. 
Larva crawled off the bean and fell into clay dust in the bottom 
of the chamber. 
Replaced on the bean. 
Caudal end attached, body moving to and fro. 
Larva dead at the spot where it was left at 6:00 P. M. the 
preceding day. 
Table 12. Record of Two Just Hatched Larvae Each Placed on a Bean 
and Surrounded by a Dirt Ring About One Quarter of an Inch in Diameter. 
Larva No. 1 was Surrounded by a Ring of Milltown Ball Clay No 9 Dust 
and Larva No. 2 by a Ring of Hydrated Lime. 
3-29-’23 
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< < 
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3-30-’23 
8:00 A. M. 
Larvae placed. 
No. 1 larva crawls about within tjie dust ring. 
No. 2 larva crawls about within the dust ring 
No. 1 larva stops crawling 
No. 2 larva looks as if it were trying to drill into the bean 
No. 1 larva pushes into the dust ring 
No. 2 larva pushes into the dust ring. 
No. 1 & No. 2 larvae so covered by dust that they can hardly 
be seen. 
No. 1 & No. 2 larvae moving under the dust 
No. 1 & No. 2 larvae dead at the points where they were ob¬ 
served at 5:00 P. M. the preceding day. 
On April 5, 1923 a larva was observed drilling into a bean where the 
bean surface lay adjacent to another bean. One and one-half hours were 
required for the larva to bury itself in the bean. In this instance the 
beans had not been treated with dust of any kind. 
The writer’s observations indicated distinctly that the larva was 
unable to grapple the bean surface because of the slipping of the fine 
particles of dust which its claws, and frequently its anal sucker seized 
upon. In fact, in many instances the writer saw the larva extend the 
front end of its body, attempt to lay hold of the bean surface and pull the 
caudal end forward. In most cases the front end simply slipped back¬ 
ward without, in any way, lifting the caudal end. Likewise, he ob¬ 
served that the front end would sometimes become seated, the anal 
would be pressed down on the surface of the bean, and an attempt made 
to shove the front end forward. In most, of these instances instead of 
the front end going forward the anal sucker slipped backward. 
In view of these observations, the writer believes that the inability of 
the larva to enter the bean which has been coated with a dust is due to 
its inability to grapple the surface of the bean firmly enough to give it a 
