THE CANADIAN ENTOMOLOGIST. 8 



o 



colour from amber to grayish. The general colour of the scale varies 

 also from nearly black to a grayish tinge, depending largely upon the 

 plants upon which it is found. The scale is very delicate, more uniform 

 in general colour, approaching perniciosus nearer than it does Forbesi in 

 this respect. 



The structural characters of the mature females are very marked. 

 \n perniciosus, the two pairs of anal lobes and the absence of spinnerets 

 are very characteristic. In a?uyius, while there are two pairs of lobes 

 also, they are usually very broad and flattish, the second pair being widely 

 separated from the first. The presence of the spinnerets is also a dis- 

 tinctive mark for this species, and if the lobes are carefully examined, 

 this species need not be confounded with either perniciosus or Forbesi. 

 In Forbesi, the two pairs of anal lobes approach perniciosus much more 

 than they do ancylus, but Forbesi can be distinguished readily from 

 perniciosus by the presence of conspicuous thickenings of the body wall, 

 forming club-shaped masses between the lobes. The spinnerets are 

 always present, usually arranged in five groups in the mature female. In 

 this connection, I might say that I have never seen spinnerets in any of 

 the immature forms of either ancylus or Forbesi. 



There are a few characters presented by the plant which will serve 

 as a mark for identifying the species. On most of our deciduous fruit 

 trees there is a purplish tinge formed about the scales of all three species 

 on young succulent wood. This tinge varies considerably, and depends 

 largely upon the trees, showing more plainly upon some varieties than upon 

 others. With perfiiciosus the purple extends into the bast, and on some 

 veiy badly infested apple trees I have seen even the young tender wood 

 coloured to bright carmine. I have also seen the fruit of peach badly 

 spotted on account of the attacks of perjiiciosus, and on some varieties 

 the colour extended into the flesh, sometimes to a depth of a quarter of 

 an inch. The purplish tinge caused by ancylus and Forbesi is usually not 

 so marked as in perniciosus. The bast is brightly coloured at times by 

 both these species, but this does not occur as often as with perniciosus. 



Forbesi also causes a peculiar rough, pitted appearance upon 

 peach and apple that is not usually produced by either a?icyhis or per?ii- 

 ciosus. The insect seems to retard the cellular growth of the plant 

 immediately surrounding it, and it is not an uncommon thing to find 

 isolated matured females in rather deep depressions. This character is 

 especially prominent on apple and peach in the nursery. 



