DISEASES OF CITRUS TREES ] 85 



general colour being white or dirty white The larva 

 is dark brown, and when it begins to form the waxy 

 covering, it attaches itself definitely on the twigs and 

 branches. These two species are common in North 

 America upon Citrus trees, the Quince, the Holly and 

 other shrubs. The second, Ceroplastes cirnpedifonnis, 

 has been introduced in these Islands probably towards 

 1905, and sometimes is common on the false pepper 

 (Schinus Molle) and on the quince, but has not been 

 noticed on Citrus trees. 



Ceroplastes Rusci Targ., the fig-scale, (Maltese 

 miscta tat-tin). This is of about the same size as the 

 Barnacle scale. The mature insect has a convex and 

 thick scale of white wax, consisting of a large central 

 prominence surrounded laterally by eight smaller ones, 

 much like the shell of a tortoise. When young the 

 prominences are better defined as white clots on a 

 pink ground due to the red colour of the body of the 

 insect. It has three broods, the most numerous being 

 that which takes place in July or August and is the 

 second brood. It has a large red-coloured larva, quite 

 visible to the naked eye. Fig-trees often suffer severely 

 from this scale, which is also very common on the 

 custard-apple. It is sometimes found on the quince, the 

 apple, the pear, the mulberry, the vine and the lemon. 

 Orange trees appear to be perfectly immune ; a curious 

 fact, when it is remembered that in Italy this scale is 

 a common parasite in the orange grove. 



The Coccineae or Mealy Bugs, include two species 

 which are very injurious to Citrus trees, viz: DactylopL2is 

 Citri, and I eery a Purchasi. 



Dactylopius Cttri Signoret, or D. destructor 

 Comstock, the orange mealy bug, is fairly common 

 especially upon lemon trees. It is a scaleless insect, 

 about 3 or 4 m.m. long, of a brownish yellow or pink 

 colour. Its body is covered by a mealy powder, and 

 tufts of white waxy filaments, and has a series of short 



