NATURAL ENEMIES OF THE OOCCTD^E : BIRDS. 37 



2. MytUaspis pomorum (puparium containing ? and 



3. Asterodiaspis quereicola (puparium containing ? 

 and eggs). 



4. Lecanium (adult ? ). 



And from observations in the field I am able to add 



5. Chionnspis salicis (puparium containing ? and 

 eggs). 



6. Pnlvinaria ribesise (immature ? ). 



1, 2, and 5 belong to the sub-family Diaspinae. Of 

 these, Aspidiotus zonatus is one of the most perfect 

 examples of protective resemblance among British 

 insects, and even to the practised eye of the collector 

 is with great difficulty found during the winter months, 

 when its shield-like covering becomes almost indis- 

 tinguishable from the dark brown or blackish bark of 

 the oak on which it lives. It is a very generally 

 distributed insect, but never, to my knowledge, occurs 

 in sufficient numbers to cover the branches of its food- 

 plant, as do many species of Coccidae. This is not to 

 be wondered at, as it is also much subject to the 

 attacks of hymenopterous parasites. 



Mtftilaspis pomorum is not only an abundant in- 

 sect, but is the most injurious of all the indigenous 

 Diaspinae. It is a much more conspicuous insect than 

 1, but the colour of its scale harmonises very well with 

 the bark of the tree on which it lives, and when the 

 colonies become overcrowded, as is often the case, they 

 are much more difficult to detect. This species is 

 almost immune from the attacks of insect enemies. 

 I have occasionally found a perforated scale, denoting 

 the escape of a parasite, but such instances are very 

 rare. On the other hand, we have abundant evidence 

 from the post-mortem examinations to show that the 

 blue titmouse feeds extensively upon this insect during 

 the winter months, and that out of twenty-one examina- 

 tions ten stomachs were found to contain examples of 



