12 BULLETIN NO. 3, DIVISION OF ENTOMOLOGY. 
DEPARTMENT OF AGRICULTURE, 
ENTOMOLOGICAL DIVISION, 
July 6, 1882. 
Mr. Cuas. G. Rockwoop, Newark, N. J.: 
Dear Sir: Your favor of the 4th instant, with accompanying box, duly to hand. 
The worms you send, and which are so destructive to your cranberries, are the larve 
of a saw-fly (family Tenthredinide ; order Hymenoptera) belonging apparently to the 
genus Dolerus. I have found the same larva feeding on Juncus at Saint Louis, but 
it has not before been reported to attack cranberry plants. The subject is therefore 
of great interest to me, and you would greatly oblige me by sending on as many of 
the worms as you are able to find, packed according to the. above-printed directions, 
I would also be thankful for any further observations you could furnish on the habits 
and development of this pest. 
Yours, truly, 
Opn) iad Bald 6 
Entomologist. 
NEWARK, N. J., July 7, 1882. 
C. V. Riney, Esq., Entomologist, etc. : 
Dear Str: Your favor of the 6th received. I have written to my farmer to send 
you more specimens. We thought when I was there that the worms had nearly done 
their work; and at noon, when we tried to find them to send you, we could only find 
the old ones. I had earlier in the day found one old one, before I thought of consult- 
ing you. They had been on the land about two weeks, and at one time parts of the 
bog were black with them. Worms supposed to be the same had been on a neighbor- 
ing bog two or three years ago, and disappeared about July 1. They have not been 
seen there either year since, although the owner thought he found their eggs. The 
same worms (so supposed) have been this year on farms 5 or 6 miles from us. They 
are also on the cranberry bogs near by us. Weare inthe pine barrens. The cranberries 
are surrounded with dikes or dams, so as to be completely covered with water in the 
winter, from, say, December 1 to May 10, more or less, according to seasons and accord- 
ing to the facilities of each location, each not having equal supply of water. We did 
not get ours fairly flowed last year till near the end of December. I think the water 
was off by May 10 or 12, having been let down gradually to addle the eggs of insects. 
We found on July 4, in searching for full-grown insects, dead bodies all in shape, but 
which when handled fell to pieces. Ihave told my farmer if he found others to send 
‘them to you. 
The cranberry is an evergreen. The worms preferred grass and ate the grass grow- 
ing among the vines first, and then took only the new this year’s tender growth of the 
vines and the buds for this year’s fruit, leaving the vines just as they were before the 
season’s growth began. The old growth was not touched. 
On the reeds where we found the young worms we found no evidence of the young 
worms eating the reeds. In one instance, near the worm, I noticed a little place 
three-eighths inch long where the reed had been gnawed, and it may have been done 
by the worm. f 
Respectfully, 
CHAS. -G. ROCKWOOD. 
Pp. S.—As to the damage, about three-fourths of the buds for this year on my land 
have been eaten, and three-fourths of the new growth for next year’s bearing. My 
crop will therefore be cut down three-fourths of the expected yield of 2,000 bushels. 
The new growth has time yet to grow again and form buds for next year. That 
you may judge of the importance of this matter, I will say that the loss may be esti- 
mated in money at, say, $2,000. 
