[149] BIOGRAPHY OF HEMILEUCA MAI A. 17 



states that they enter the ground for their transformation. Harris 

 says that the moth has been reported to him as occurring in July and 

 the beginning of August. The description of the larva given in 

 Morris' Synopsis is also inapplicable to it. In a notice of a commu- 

 nication read by Mr. Wood before the Entomological Society of 

 Philadelphia,* it is asserted that the larvae " went into the ground the 

 last of August, 1859, and became perfect insects on October 10th, 

 1860." We believe this statement to be an error, which may have 

 occurred either in inserting in the report the supposed years not men- 

 tioned in the communication, or the transformation of the August 

 (1859) larvae into imagines in October of the same year may have 

 escaped the observation of Mr. Wood " near the sea-shore ;" and he 

 would, therefore, naturally refer the moths observed by him in Octo- 

 ber, 1860, to the larvae of the preceding year. It is very improbable 

 that a transformation, requiring less than two months of a cool, within- 

 door temperature during the latter part of summer, would, under 

 natural conditions, be extended over an entire summer and prolonged 

 to fourteen months. (See note appended.) 



Mr. Walsh writes of it:f "The larvae are at first entirely black. 

 When full grown they have a yellow band, variegated with short black 

 lines on each side of the body ; the head and collar are chestnut-brown. 

 During the month of August they descend into the ground, where 

 they change to chestnut-brown chrysalids." Our larvae were without 

 the band and short black lines, and the pupae were chestnut-brown 

 only in the brief interval between the casting of the larva-skin and 

 their assumption of their normal color. 



Rarity. The moth is quite rare in the State of New York. It 

 had never been taken by me during fifteen years of collecting ; and 

 I have heard of its capture but once in this State, an individual hav- 

 ing been caught a few years since in the vicinity of Albany. The 

 number of clusters of its eggs found at Center, without search having 

 been made for them, would indicate a greater frequency of its occur- 

 rence. 



Its rarity may find an explanation in the social habit of the larvae 

 during the first half of their existence. Unfortunately possessing a 

 color in marked contrast with the leaves on which they feed, even a 

 solitary individual would be but illy fitted to escape the searching eye 

 of bird or parasite that preys upon it; but assembled in a compact 

 mass, and feeding without the slightest attempt at concealment, it is 

 simply impossible for it to elude detection. Its formidable array of 

 spines undoubtedly induces many of the insectiverous birds to pass it by 



* Proc. Ent. Soc. Phil, 1867, vol. 1, p. 46. 

 f American Entomologist, 1868, vol. 1, p. 186. 



