THE CANADIAN ENTOMOLOGIST. 235 



the seventh and eighth segments, and another on the two hindermost 

 segments. Each segment was adorned with semi-transparent tubercles, 

 which were pale on the pale patches and dark on the other portions of 

 the body ; each tubercle was armed with a few short black spines. On 

 each side of second segment is a prominent tubercle with two smaller ones 

 between them ; the third, fourth and fifth segments have six tubercles on 

 each, arranged in irregular transverse rows ; the remaining segments have 

 only two tubercles. Body thickest towards the front, tapering behind. 



MOTHS INJURIOUS TO VEGETATION. 



BY A. R. GROTE, A. M. 



Under this head one might arrange nearly the whole of our moths, 

 except, perhaps, a little species, the Euzephora eoccidivo?'a, which Profes- 

 sor Comstock has discovered to be predaceous, and to live upon plant-lice 

 in the larval state, and one or two others, which, perhaps, have similar 

 habits. A good many species become unusually numerous, however, in 

 certain years and locahties. Almost always this seems to be owing to the 

 temporary cessation of action of the checks which keep down species from 

 excessive multiplication, and disturbing the o'rder of things. When we 

 cultivate a large quantity of any cereal or plant of economic value, we in 

 effect afford abundant food for the insects which habitually infest it. 

 Many will recollect that the maple and other shade trees in Brooklyn and 

 New York used to be completely defoliated by the middle of summer by 

 the common Brown Drop or Measuring Worm, Eudalimia subsignaria. 

 The Enghsh sparrow rid us of this nuisance ; it eat every one of them. 

 This Measuring Worm sought refuge in the cities from the birds which 

 attacked it, and kept it down in the country. In the cities the birds were 

 less plentiful and, this check being removed, they throve exceedingly. 

 When the Measuring Worms were gone their place was taken by a differ- 

 ent moth, the Gray Vaporer, Orgyia leucostigma, whose caterpillars, 

 being hairy, were unpalatable to the sparrows. In Philadelphia this sub- 

 stitution merely exchanged one nuisance for another, so plentiful have the 

 Vaporer caterpillars become. In Buffalo, where the Vaporer was 

 always the prevailing pest, no change has been made upon the entry of 



