NATURAL ENEMIES OF THE COGCTDM. 29 



sopa, sp.) on beech trunks infested with Cryptococcus 

 fagi, Barensp., but have never found the larvae feeding 

 upon the Coccid. 



On one occasion I found a number of specimens of a 

 species of Thrips amongst the thick cottony ovisacs of 

 Gryptococcus fagi, but for what intent I cannot say. It 

 is just possible they may have been feeding upon the 

 Coccids ; but most probably they were in hiding, and 

 that they found near at hand abundance of vegetation 

 suitable as food. 



The insects which commonly infest the Coccidae are 

 a family of the Hymenoptera, chiefly belonging to the 

 Chalcididae, and are allied to the bees and wasps ; they 

 are very minute, and many are of a bright metallic 

 green colour. These parasites chiefly infest the large 

 Lecania, and are capable of materially altering the 

 form and external character of these insects. In 1891 

 (' Entomologist's Mo. Mag., 5 S.S., vol. ii, pp. 267, 268) 

 I called attention to this, and it may be useful to quote 

 what was then stated : 



" I have examined a good many species of Lecanium, 

 and find that several are subject to considerable vari- 

 ation in the form of the scale ( ? ), and this entirely 

 from the attacks of internal parasites. Of these 

 there are at least two species* very common, and 

 both, so far as I have been able to trace, produce 

 abnormal swellings, peculiar to the species, on the 

 dermis of the host. The most important of these is 

 that which produces one, two, or more large tubercular 

 swellings generally two ; when the latter is the case 

 the scale appears quite symmetrical, the swellings 

 being on either side of the dorsum, opposite to each other. 

 When there is but one large tubercle it is invariably 

 situated on one side of the dorsum, thus giving the scale 

 ( ? ) a " lop-sided " appearance, which at once attracts 

 the eye as curious and unusual. I find that each 

 of these tubercular swellings, if examined in season, 



* I am now of opinion the difference was sexual, and that the 

 species causing the swelling is the Blastothrix sericea, Dal. 



