The pear slug in an old enemy of fruit trees, and while it has been 

 known in this country for over a hundred years as an American species, 

 the interesting fact that it is the familiar slug-worm pest of the pear and 

 plum trees of Europe has not hitherto been definitely ascertained. In 

 Massachusetts, toward the latter part of the last century, this insect 

 became very destructive, and Prof. \Vm. D. Peck prepared an admira- 

 ble, illustrated account of it under the title of " Natural History of the 

 Slug Worm," which was printed in Boston in 1799 by the Massachu- 

 setts Society for the Promotion of Agriculture. The author obtained 

 for the production the society's premium of $50 and a gold medal. The 

 account of this insect given by Professor Peck is fairly complete and 

 accurate, but foi- fifty years it has been out of print and inaccessible, 

 and I have not l)een able to consult it. Harris abridged and condensed 

 it for his account of the slug- worm in his "Insects Injurious to Vegeta- 

 tion," published in 1841, and later writers have generally followed 

 Harris. 



In Europe this insect was one of the first of the injurious species that 

 attracted attention, and one of the earliest of the economic writers on 

 insects, Reaumur, in the fifth volume of his bulky work published in 

 1740, gives a short account of it, together with recognizable figures of 

 the insect in different stages, illustrating also the effect of its work on 

 leaves. The first description and name which stands out unquestioned 

 is by Retzius (1783), who describes the species as Tenthredo limacina. 



Linne, in describing what seems to have been an entirely distinct in- 

 sect, which he called Tnifhrrdo crrasi, quotes Reaumur's account of the 

 slug-worm, which he erroneously took as belonging to his species, and 

 very generally since, therefore, the former has been called cerasi Linn. 

 (Cameron.) 



Professor Peck in describing the insect gave it the name suggested by 

 Linne, and was of the belief that the species occurring about Boston 

 was at most a mere variety of Linne's species, meaning, however, the 

 common pear-slug fiy of Europe. Later American writers have treated 

 it as a native species, and under the genei'ic name of Selandria or Erio- 

 campa. Peck has had the credit for it in this country, and the fact 

 that Peck himself associated it with Linne's species has been generally 

 overlooked. 



That the species so common in this country is identical with the slug- 

 fiy of Europe has been full}' established by a comparison of specimens 

 from Europe with abundant American material. 



In Europe this insect has been the subject of description by innu- 

 merable authors, having received at least nine different specific names 

 and having been referred to some eight genera. In this country it has 

 also been the subject of many short notices, but of very few full accounts 

 other than the one published by Peck. 



