iZ OUR SHADE TREES AND THEIR INSECT DEFOLIATORS. 
Mr. Glover regarded the pupa state as the most favorable in which 
to kill the insect, as it can then be easily crushed or scalded. Con- 
cerning the tobacco treatment he adds that “syringing the trees with 
strong tobacco water has been tried with some good effect, but the 
larve not touched by the fluid are merely knocked down by the concus- 
sion, and, if nearly ready to change into pupe, effect their transforma- 
tion where they fall.” 
In this connection we cannot do better than quote what we published 
in 1880* in reply to certain statements by Dr. J. L. Le Conte, as fol- 
lows: 
Anent Galeruca xanthomelena, which is becoming more destructive each successive 
year to the shade elms in our northern towns, a correspondent mentions the following 
facts: 
1. The trees are not all attacked at the same time, but the insect seems to break 
out from a center, gradually destroying the more remote trees, so that isolated trees 
remain comparatively free. 
2. After applying a band (saturated with fish-oil, petroleum, &c.) to some trees 
which were about half denuded, found hundreds of the worms stopped both in ascend- 
ing aud descending the trees. 
He also propounded the following query: 
3. Do the beetles hibernate in the ground, so that rena can be poisoned, or are they 
perpetuated only by the eggs on the trees: 
Allow me to add the following subjects for investigation as necessary to the devis- 
ing of proper remedies against this foreign invader: 
4. How soon do the insects appear in the spring; how rapidly do they propagate; 
and what time is passed in each stage of development? 
5. Are the larve and beetles eaten by insectivorous birds, or are they protected by 
offensive secretions, as is the case with Doryphora 10-lineata, Orgyia leucostigma, and 
several other noxious insects? 
6. What proportion of the brood hibernates, and in what stage, pupa or perfect 
insect, and where? 
If the materials for furnishing answers to these questions are not yet within your 
reach, will you kindly direct the attention of some of your trusty observers to the 
subject, so that persons interested in the preservation of the shade trees which are so 
justly esteemed may be properly instructed as to the measures to be adopted during 
the next summer. 
Very truly, yours, 5 Mek ia eer 
2 oa 
Philadelphia, Pa. 
The above inquiries were received from our esteemed correspondent some time since, 
and we employ them as a ready means of giving our experience with the beetle. 
For the benefit of the general reader it may be remarked that the natural history 
of this Elm Leaf-beetle is quite similar to that of the well-known Colorado Potato- 
beetle and of the Grape-vine Flea-beetle. The only deviation in the Elm Leaf-beetle 
is in the mode of pupation, which rarely takes place in the ground, unless this be 
very friable, but at the base of the tree or under any shelter that may present itself 
near the trees, such as old leaves, grass, &c. 
(1) The phenomenon here described is doubtless due to the gradual increase in 
spring from one or more females. 
(3 and 6) Like most, if not all, Chrysomelidw, the Elm Leaf-beetle hibernates in the 
perfect state. As places suitable for hibernation abound, any ee to successfully 
* American Entouving ae ibecemmen 1880, p. 291. 
