﻿90 SEVENTH ANNUAL KEPORT 



marked on each side with two transverse blackish stripes ; the back ash-colored, marked 

 lengthwise with small, interrupted dusky lines; the sides blackish, with a pale line 

 along the length of the body ; there are two white spots on the last segment of the 

 l)ody ; the abdomen or underside is ash-colored. * - * 



The chrysalis state comes on in twenty-four hours after the larva has penetrated the 

 ■earth ; and it appears that the insect is soon perfect, since a course of warm weather 

 has been found to raise some of them from the earth in the month of November. 

 While they are in chrysalis they are uninjured by frost. Their natural and regular 

 time of rising is about the middle of March, but happens sometimes as early as the 

 twelfth, and is sometimes retarded to the twents'-fourth, according to the warmth or 

 ■coldness of the season. They continue to rise for a longer or shorter time, according 

 to the greater or less depth at which they lie, and the extrication of the frost from the 

 earth^commonly from twenty to thirty days. '"' * * Like others of the moth kind, 

 they are active only in the night, and in the day time sit close to the bark of the tree, 

 whose color is so similar to theirs that they are not seen without near inspection. * * * 



The principal check provided by Nature, upon the too great increase of this insect 

 is the Ampelis garrulus ot Linna3us, called by Mr. Catesby, the Chatterer of Carolina, 

 and in the Rev. Doctor Belknap's History of New Hampshire, Cherry-bird. This bird 

 destroys great numbers of them while in the larva state. Another check is a disease 

 which may be called Deliqidum, and is probably occasioned by a fermentation of their 

 food. In this disease the whole internal structure is dissolved into a liquid, and noth- 

 ing is entire but the exterior cuticle, which breaks on being touched. 



The Canker-worm is said to have been observed first in the Southern States, where 

 it is probably a native. It is certain it must be spread by some means Independent of 

 itself, since the female, by the privation of wings, is forbidden to range. 



It may have been introduced into New England by the importation of trees from 

 the Southern States, on which the eggs were deposited ; or disseminated in the larva 

 state, in all populous parts of the United States, by falling from trees upon carriages 

 and travelers passing under them. 



This conjecture is rendered probable by its being found in all places which have 

 intercourse with such parts as are infected with it, and by its being unknown in new 

 settlements. 



THE GRAPE PHYLLOXERA. 



The following notes on this insect are intended to supplement 

 the article in the Sixth Report, and should be read in connection with 

 said article. It is my desire to give a record of observations and dis- 

 coveries, in the matter of Phylloxera, with as little repetition of what 

 has previously appeared in these reports, as is consistent with intelli- 

 gibility. 



COMPLETION OF ITS NATURAL HISTORY. 



During the year the natural history of the species has been all 

 but completed; as I predicted it would be, after Balbiani had paved 



