LEPIDOPTERA. 315 



preparatory stages of a European species. This moth does 

 not appear to have been described. It is named in my Cata- 

 logue of the "Insects of Massachusetts," HepioUis arp^t'uleo- 

 maculatus, the silver-spotted Hepiolus. Its body and wings 

 are rather long. It is of an ashen gray color; the fore wings 

 are variegated with dusky clouds and bands, and have a small 

 triangular spot and a round dot of a silvery white color near 

 their base ; the hind wings arc tinged with ochre-yellow 

 towards the tip. It expands two inches and three quarters. 

 A much larger specimen was found by Professor Agassiz near 

 Lake Superior.* 



The locust-tree, Robinia pseudacacia, is preyed upon by 

 three different kinds of wood-eaters or borers, whose unchecked 

 ravages seem to threaten the entire destruction and extermi- 

 nation of this valuable tree within this part of the United 

 States. One of these borers is a little reddish caterpillar, 

 whose operations are confined to the small branches and to 

 very young trees, in the pith of which it lives; and by its irri- 

 tation it causes the twig to swell around the part attacked. 

 These swellings being spongy, and also perforated by the cater- 

 pillar, are weaker than the rest of the stem, which therefore 

 easily breaks off at these places. My attempts to complete 

 the history of this insect have not been successful hitherto. 



The second kind of borer of the locust-tree is larger than the 

 foregoing, is a grub, and not a caterpillar, which finally turns 

 to the beetle named Clijtus piclus, the painted Clytus, already 

 described on a preceding page of this work. 



The third of the wood-eaters, to which the locust-tree is 

 exposed, though less common than the others, and not so 

 universally destructive to the tree as the painted Clytus, is a 

 very much larger borer, and is occasionally productive of great 

 injury, especially to full-grown and old trees, for which it 

 appears to have a preference. It is a true caterpillar, belong- 

 ing to the tribe of moths under consideration, is reddish above, 

 and white beneath, with the head and top of the first ring 

 brown and shelly, and there are a few short hairs arising from 



* See a figure of it in his " Lake Superior," pi. 7, fig. 6. 



