THE PEAR-TREE SLUG. 529 



of " The Gardener's Magazine." It is possible that our 

 slug-fly may have been imported from Europe, and it may 

 turn out to be really a mere variety of the European insect. 

 Professor Peck was aware that it did not agree with the 

 description given by Linnaeus of the latter ; and it appears 

 to me that the difference between the two insects, in their 

 winged state, is enough to entitle them to be considered as 

 specifically distinct from each other. For this reason I shall 

 retain for our insect the specific name adopted by Professor 

 Peck, because this slug does really live upon the cherry, in 

 this country, as well as on the pear-tree ; and shall merely 

 prefix to it the generical name which it should bear accord- 

 ing to modern nomenclature. The fly of our slug- worm 

 may therefore be called Selandria {Blennocampa) Cerasi. 

 The meaning of the word Selandria is unknown to me. 

 Blennocampa signifies slimy caterpillar, a name which, it 

 will be seen, may be applied with great propriety to our 

 slug- worm. 



This slug-fly is of a glossy black color, except the first 

 two pairs of legs, which are dirty yellow or clay-colored, 

 with blackish thighs, and the hind legs, which are dull 

 black, with clay-colored knees. The wings are somewhat 

 convex and rumpled or uneven on the upper side, like the 

 wings of the saw-flies generally. They are transparent, 

 reflecting the changeable colors of the rainbow, and have 

 a smoky tinge, forming a cloud or broad band across the 

 middle of the first pair ; the veins are 

 brownish. The body of the female (Fig. 

 248) measures rather more than one fifth 

 of an inch in length ; that of the male is 

 smaller. In the year 1828, I observed 

 these saw-flies, on cherry and plum trees, in Milton, on 

 the 10th of May ; but they usually appear towards the end 

 of May or early in June. Soon afterwards some of them 

 begin to lay their eggs, and all of them finish this business 

 and disappear within the space of three weeks. Their eggs 



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