236 JOUENAL OF THE EOYAL HORTICULTURAL SOCLETY. 
quaoitities of plants are grown, "sponging" would be a most effectual 
means of dealing with the pest. 
I have recently received a new and undescribed species from the 
''Temperate House'' in the Royal Gardens, Kew, for which I propose 
the specific name keicensis. It was infesting a species of Howea, and 
was very abundant. Superficially the covering scale resembles a white ^ 
Chionaspis. 
Common Mussel Scale 
{ My t ilaspis j^ojuomm, Bonche). (Fig. 102.) 
One of the best known of British coccid pests, occurring almost every- 
where on Apple. Pear, Hawthorn. Cotoneagter, and a variety of other 
plants. 
The covering scale is shaped like a mussel shell, and varies from 
a light red to a dark brown colour, with the yellowish larval skin 
Fig. 102. — Mytilaspis pomorum S (magniliedi. 
attached to the narrow or anterior extremity. Under this covering the 
white or almost colourless female may be found fully developed 
towards the end of August. About that time and during September 
twenty-five to forty white eggs are laid, which remain within the 
scale until the following May (last week) and early in June. At 
this time the active little white larvfe ("lice") may be found dis- 
porting themselves over the tree trunks and branches. About six weeks 
later the perfect male appears, and thus the cycle is completed. 
The male, however, has proved so exceedingly rare that, until its 
discovery in England by the writer three years ago, it had remained 
unknown for 150 years. It is true the late Prof. Riley figured and 
described what he supposed was the male of this species, but his accu- 
rate description of the sex leaves no doubt in my own mind that he 
had the male of some other Diaspid before him. Dr. Gustavo Leonardi, 
of the Royal School of Agriculture, Portici, Italy, has also succeeded in 
rearing it. Not the least remarkable fact concerning its discovery is 
