DISEASES OF THI. VINE. ] 595 



as well as the winged insect, feed on the foliage of the 

 vine, but are rarely numerous enough to cause serious 

 injury. A. stridulum, L, the red-winged locust, is a 

 fourth species common in France and Italy. The scale- 

 insects are represented by Pulvmaria 1/itis, L., and Le- 

 canium Vini, Bche, the first species with its characteristic 

 cushions is occasional iy present in our vineyards. L^eca- 

 nium cannabinum and Ceroplastes Rusci occasionally visit 

 the vineyard, but are not known to give serious trouble. 

 Dacfylopins Lifoi, one of the mealy bugs is frequent on 

 the vine, particularly if trained on pergolas, and Dactylo- 

 pius Vitis, Nied. is another mealy bug which lives on the 

 green parts, and on the berries which it destroys, but 

 resides chiefly on the roots. 1 his mealy bug is known 

 to cause indirectly serious havoc in the vineyards of 

 Northern Africa and Palestine (Jaffa disease), where in 

 order to seek protection from the heat it descends to the 

 base of the stem and to the roots, causing wounds in 

 those tissues from which exudes a sugary liquid which 

 moistens the soil all round. On the stem and roots 

 moistened with this honey dew, as well as in the soil 

 saturated with this liquid develops a fungus (Bornetina 

 corium], whose mycelium forms a thick mass which 

 protects the insects from the drying heat, but destroys 

 the roots by depriving them of air, and the vine dies 

 soon after. The disease, often called phthyriosis, may 

 extend over large areas and then assumes a grave 

 character. As a remedy it is recommeded to make use 

 of quicklime digging it deeply around the stem of 

 infected trees. Carbon bisulphide injected into the soil 

 close to the stem is also a good remedy, in both 

 cases the remedy acting against the insect and against 

 the fungus. 



Another scale-insect closely allied to the mealy bugs 

 is Rhizoecus falcifer, Kunckel, which is known to exist in 

 North Africa and Sicily. The original host plants of 



