ufol 



142 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



tice concerning the same, sent last year from the Arboretum. The museum is very 

 rich in Nematus, but does not possess this species, which is very rare in Europe, ami 

 has only twice before 1840 been observed to be very obnoxious to the larch in Hol- 

 stein by Tischbein andintheHarzby Saxesen. Ratzeburg, in his last work, remarked 

 only that it is rare, but may prove to be rather obnoxious. The species is, so far as I 

 know, not described among the United States species, surely not under its original 

 name. 



,The following note by Dr. Hagen, extracted from the Canadian Ento- 

 ogist, is the one referred to in the foregoing letter : 



Nemaius ericlisonii on Larix enropcea. A large number of larvas, very young to nearly 

 full-grown, some probably full-grown, were sent living, with the twigs. The larvie 

 agree perfectly with description and figure in Ratzeburg's Forst-Insecten, Tom. Ill, 

 PI. 3, Fig. 4. The species is not represented in the collection here, neither in the larva 

 nor in the imago state. It is not mentioned in Mr. Norton's catalogue of N. Am. Ten- 

 thredinidaj. I have to remark that the larva} of the three other species living in Eu- 

 rope on Larix. viz, Lyda laricis, Nematus soleus, and compressus, from their description, 

 do not agree with those sent to me. I am indebted to the Harvard Arboretum and 

 its director, Mr. Charles S. Sargent, for these specimens. Canadian Entomologist, 

 Vol. XIII, No. 2, p. 37, 1881. 



Its appearance in Northern New York. Mr. George Hunt, of Providence, 

 who is a close observer of plant and insect life, and who annually visits 

 the Adirondack region in the vicinity of Scroon Lake, informs us that 

 about July 25 and early in August the hackmatacks were seen to be 

 entirely defoliated, no leaves being left on the trees by the first of 

 August $ he observed the effects of the worms at Horicon, Warren 

 County, and Scroon Lake, in Essex County, as well as at Pottersville. 

 The region affected^was very extensive, covering many square miles in 

 different swamps. No worms were observed in 1881. He has presented 

 us with some of the worms, which are of full size, and do not differ 

 from Maine specimens. They were fully grown July 28. 



HISTORY OF THE SPECIES AND ITS HABITS. 



Notwithstanding the efforts made to rear the larvae of this species 

 last summer, no perfect insects were obtained, the cocoons furnished us 

 by Mr. Atkins having been all parasitized by a species of Pteromalus, 

 a parasite of the hymenopterous family Chalcididse; while of two false 

 caterpillars which spun cocoons, neither had hatched up to the time of 

 writing. 



On referring to the great work of Eatzeburg on forest insects, the 

 admirable colored figure of the larva of Nematus erielisonii which he 

 gives exactly represents the peculiar style of coloration of our worms ; 

 we had identified it as perhaps this species, or as the young of one rep- 

 resenting it in this country. 



It appears by the foregoing extracts that Professor Hagen had exam- 

 ined the larva and had identified it as Nematus erichsonii. We are 

 unable to find any differences in the larvae from the figure of the Euro- 

 pean species, and the cocoons are of the size and form as figured by 

 Ratzeburg. A description of the fully grown larva is not given by 

 Ratzeburg. The eggs are described by Ratzeburg (after Tischbein) as 

 about one-half a line (%") long, white, transparent, laid in a row upon 

 and within the young larch shoots. The following is a free translation 

 of his description of the saw-fly, which he calls the large larch saw-fly, 

 and figures in Theil III, PI. HI, Fig 4. 



4-5"' long and wings expanding 10-11.'" In sculpturing and coloring so great a simi- 

 larity with N. aeptentrionalis $ that it would be mistaken tor it, were it not for the tarsal 



