14 BULLETIN NO. 3, DIVISION OF ENTOMOLOGY. 
There is but little grass on the cranberry bogs under cultivation, and it was found 
that those squares had suffered most on which there was most grass, while on those 
squares where the cranberry vines had nearly exterminated the grasses very little or 
no damage at all had been done. 
No living specimens of the insect that really did the damage could be found, as was 
to be expected after the lapse of more than six weeks, the worms having been seen 
on the bog about June 20; but the following traces thereof were discovered: 1. The 
ground on the damaged squares was literally strewn with excrement, which, though 
much decomposed at this time, was unmistakably that of a Lepidopterous larva; 2. 
Numerous heads of a Noctuid larva were found on the ground, most of them in a badly 
decomposed state, and but a few among them in fair condition. These heads were 
so abundant that there could not be the least doubt that they belonged to the de- 
structive larva. The Sarracenias growing in some places in the bog each contained 
numerous specimens of the decomposed larvx, but in the course of the examination 
a few fairly well preserved specimens were found; 3. Of pupze, or rather empty shells, 
very few could be found, and it appears that the wet ground had prevented the worms 
from entering the same, and that they mostly perished above ground without trans- 
forming; 4. A number of empty Microgaster cocoons, indistinguishable from those of 
M. congregatus. 
I will also remark in this connection that I found two specimens, the only ones I 
saw, of the saw-fly sent by Mr. Van Hise as the originator of the damage. It was 
feeding on a species of Scirpus (?) which grows in the irrigation ditches. 
The cultivated bog is flooded with water during winter and spring to a depth of 
several feet, so that no Lepidopterous larve can hibernate in it. The uncultivated 
part is also under water most of the time mentioned, but not so thoroughly as the 
cultivated portion. Outside of the cranberry lands there is but little graminaceous 
vegetation in the pine barrens. On the 10th of May the water is drawn off from the 
bog, an operation which is accomplished in little more than 24 hours. After this 
the cranberry vines and other vegetation start vigorously, the grasses, one or two 
species of which grow in thick bunches, being there much fresher than anywhere else 
in the neighborhood. 
From Mr. Rockwood’s and Mr. Van Hise’s observations there can be no doubt that 
the larve first devoured every blade of grass on the squares where the eggs were de~ 
posited and that they afterwards, from mere want of other food, began to attack the 
eranberry vines. They destroyed only the young vines (i. e., those which should have 
been bearing this and the next seasons), eating the young, fresh leaves before these 
had fairly opened. At the time of my visit these young twigs had the appearance of 
being cut with a knife. Mr. Van Hise further states that he saw the worms appear 
in great numbers at the edge of the irrigating ditches, a great many of them being in 
the water and on the rushes growing in the ditches. This observation is no doubt 
correct, as the worms, after passing through one of the squares, finally congregated 
at the edge of the irrigating ditch and tried to get across, and in doing so got at the 
rushes, which at the time of my visit still bore evidence of their attack. In general 
the irrigation ditches were evidently an efectual barrier against the progress of the 
worms, and whether they succeeded, in one or two instances, in crossing the ditches, 
or whether the damage on the adjoining squares was caused by worms that hatched on 
the same, could not be ascertained. At any rate their feeding on the rushes in the 
water was the reason of the confusion in regard to the saw-fly larve. Mr. Van Hise, 
being instructed to collect specimens of the cranberry enemy at a time when the real 
depredators had disappeared, naturally did not find any other worms on the rushes 
than the saw-fly larvee, which seem to have been very numerous in the beginning of 
July. 
In regard to other injurious insects observed by me on the cranberry bogs, I would 
mention that at the time of my visit serious damage was done by various species of 
locusts ( derididw), by eating large holes in the berries. Mr. Van Hise resorts to the 
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