1?HE STATE ENTOMOLOGIST. 131 



Both Dr. Harris and Dr. Fitch state that this worm spins its thin 

 cocoon in crevices of bark and similarly sheltered places above 

 ground, but a great many of the specimens which I have reared (and 

 1 have bred specimens three different years) buried themselves and 

 formed their cocoons just under the surface of the ground — thus giv- 

 ing evidence that the same insect will sometimes variously spin up 

 above o\- below the ground. The chrysalis (Fig. 55, b) is of a very 

 dark brown color, glabrous and polished and faintly punctured, and is 

 characterized by swelling or bulging about the middle. The moth 

 {Fig. 55, w) is white with a very slight fulvous shade: it has immacu- 

 late wings, but the front thighs are tawny-yellow and the feet black- 

 ish: in some the tawny thighs have a large black spot, while the 

 shanks on the upper surface are rufous ; in many all the thighs are 

 tawny-yellow, while in others they have scarcely any color. One bred 

 specimen in my cabinet even has two tolerably distinct spots on each 

 front wing — one at base of fork on the costal nerve, and one just 

 Within the second furcation of the median nerve. 



During the summer and fall of 1870 this worm was unprecedently 

 numerous, not only in our own State but all over the country, and, as 

 was remarked by others as well as myself, it hatched out much earlier 

 than usual ; for the first webs were noticed around St. Louis by the 

 middle of June. It has always been supposed to be single-brooded-, 

 and in the New England States it never does perhaps produce more 

 than one brood each year; but though such may be its normal habit, 

 even in the latitude of St. Louis, yet there is good evidence that it 

 sometimes produces two broods in that latitude, and in all probability 

 does so constantly still further south. There appeared to be two 

 broods with us the present year, and Mr. J. R. Muhleman, of Wood- 

 burn, Illinois, informed me that on August 5th, he had a second brood 

 of worms, the first brood having appeared in June on Pear and Osage 

 Orange. He did not, however, breed one generation from the other, 

 and until this is done during the same year, we cannot say with abso- 

 lute certainty that the species is two-brooded, for the disparity in 

 time of appearance can be accounted for in other ways. The climate 

 of the Central portion of our State is intermediate between that of 

 the more Northern and the more Southern States, but the fauno par- 

 takes more of the character of the latter; and our summers are so 

 variable in their duration and in their general intensity, that our in- 

 sects show a great variability in their habits. It is for this reason 

 that I find it very difficult to draw the rigid lines that many of our 

 New England writers have done when treating of a particular insect, 

 and it is for this reason that we frecpuently find insects, normally 

 single-brooded there, often producing two broods a year here. 



With us the Fall Web-worni appears to be most partial to the 

 hickories and to the Black walnut, and least so to the oaks; but I 

 have found scarcely any tree or shrub exempt from its attacks except 

 those already mentioned, and it is even said to feed on the Hop- 

 Plantain, Bean, Sunflower, and many other herbaceous plants. 



