COURTSHIP. 23 



quite high up, and there in summer-time construct 

 their ovisacs and lay their eggs. In the autumn the 

 larvae separate, the females remaining on the branches 

 while the males descend to the tree trunk to pupate. 

 I believe no such habits have been observed in any 

 other species ; indeed, our knowledge of the habits of 

 these insects is very limited, and there is a wide field 

 of research open to the student of nature. 



In Ghionaspis solids the bright orange-red male 

 divides his favours among the females capriciously. Its 

 success in finding the females appears to depend on the 

 delicate sense of touch in the antennae and long sabre- 

 like genital armature. Frequently several males will 

 surround a single female puparium, but there appears 

 to be no strife between them. Each gives the other a 

 place, while all are intent on discovering the passage 

 between the scale-like covering and the bark which 

 leads to the hidden female. This accomplished, the 

 armature is inserted to its full length beneath the 

 covering scale, and its course is apparently aided by 

 the insertion of the posterior legs in the way shown in 

 the illustration (PL XIX, fig. 3 a). 



MIGRATION, DISTRIBUTION, ACCLIMATISATION, ETC. 



As adult female Coccids are unable to fly, or usually 

 to walk, it is only the minute larvae which can migrate, 

 and that only in small areas ; this accounts for the 

 enormous isolated colonies of these insects which only 

 too frequently occur on a single plant or tree. Yet, 

 strange to say, there is no family of insects that has 

 a wider geographical distribution than the Coccids. 

 Take, for example, the common " mussel scale " of the 

 apple (Mytilnspis pomorum)^ a species supposed to be 

 of Palaearctic origin. It occurs as a pest in almost 

 every part of the world where the apple is cultivated 

 in Europe, North and South, the United States, New 

 Zealand, Australia, North Africa, and probably many 



