IIG POPLAR. [1899 



a cocoon from a stone wall near a Poplar tree and finding the cocoon 

 coated all over with little bits of the red coarse sandstone of the wall. 



But the instinct of the caterpillars leading them to gnaw their 

 cocoon material from the bark of their food-trees is one of their 

 especial ways of occasionally doing great harm. In the year 1890, 

 an example of this was reported to me in which the little trees were 

 so young and small that the amount of woody material and bark 

 removed by the caterpillar weakened the young Poplar plant to such 

 a degree that the stem broke off. In the specimen sent me, the 

 slender stem was completely bared of bark for some little distance 

 from the hard cocoon, and the young plantation was reported to be 

 practically destroyed. 



The moths, which may be expected to be on the wing in May, are 

 marked as shown in the figure of the male, p. 114, and are very fine 

 insects ; the male about or upwards two inches and a half in spread 

 of its fore wings ; those of the female still larger, even as much as 

 three inches and a quarter in expanse. The fore wings are white and 

 grey with darker and black markings ; the hind wings white at the 

 base but smoke coloured in the disk ; the head white, and the body 

 between the wings whitish with black spots ; abdomen whitish grey 

 with transverse darker bands. From their soft furry appearance the 

 name of Puss Moth has been bestowed on them. 



The above notes give a general description of the history and 

 habits of the infestation in its various stages, and of the colouring of 

 the caterpillar from the time that it is somewhat more than half grown 

 onwards. But in its early life the colouring is so different that it is 

 not always recognized as being the same species of larva, and on 

 June 26th in the past season a young specimen was sent me from a 

 contributor who had found it feeding on a Willow tree (Avith enquiries 

 accompanying as to its nature), Avhich gave me the opportunity of 

 watching the change of colour through all but the quite early condition. 



When hatched from the egg the caterpillar is described as "a 

 queer little creature," with warts projecting over the head like horns ; 

 of an intense sooty black above and black with claret tinge below. 



My specimen had advanced beyond the quite earliest condition, 

 but the upper part (which in mature state is of a purplish colour, 

 streaked longitudinally with white lines) was still jet black, and the 

 lower part of the body of a clear yellow. Behind the head on the 

 next segment were a pair of lumpy black processes of a somewhat 

 horn-like shape, placed on each side. These, when seen with a 

 moderate magnifying power, appeared to have several reddish spots 

 at the extremity. The larva fed fairly well on Poplar, and on June 

 29th had grown to approximately a length of half an inch. The 

 colouring was now of brown tint with minute mottling of darker 



