Chap. XII.] 



THE COFFEE-BUG. 



439 



colour, and at length is permanently fixed to the surface 

 of the plant, by means of a cottony substance interposed 

 between it and the vegetable cuticle to which it adheres. 

 The scale, when full grown, exactly resembles in minia- 

 ture the hat of a Cornish miner *, there being a narrow 

 rim at the base, which gives increased surface of attach- 

 ment. It is about ± inch in diameter, by about 

 deep, and it appears perfectly smooth to the naked eye ; 

 but it is in reality studded over with a multitude 

 of very minute warts, giving it a dotted appearance. 

 Except the margin, which is ciliated, it is entirely des- 

 titute of hairs. The number of eggs contained in one 

 of the scales is enormous, amounting in a single one to 

 691. The eggs are of an oblong shape, of a pale flesh 

 colour, and perfectly smooth. 2 In some of the scales, 

 the eggs when laid on the field of the microscope re- 

 semble those masses of life sometimes seen in decayed 

 cheese. 3 A few small yellowish maggots are sometimes 

 found with them, and these are the larvae 4 of insects, 

 the eggs of which have been deposited in the female 

 while the scale was soft. They escape when mature by 

 cutting a small round hole in the dorsum of the scale. 



It is not till after this pest has been on an estate for 

 two or three years that it shows itself to an alarming 

 extent. During the first year a few only of the ripe 

 scales are seen scattered over the bushes, generally on 

 the younger shoots ; but that year's crop does not suffer 

 much, and the appearance of the tree is little altered. 



1 Fig. 8. soft Coccus, viz. : Encystus, Cocco- 



8 Fig. 9. phagus, Pteromalus, Mesosela, 



3 Figs. 10,11. Agonioneurus ; besides Aphidius, a 



4 Of the parasitic Chalcididise, minutely sized genus of Ichneu- 

 many genera of which are well monidae. Most, if not all, of these 

 known to deposit their eggs in the genera are Singhalese. 



F F 4 



