MELOLOXTHA HIPPOCASTANI. 209 



should intervene to compel unanimity. This is done in 

 France by order of the prefects. The damage done by cock- 

 chafers to agriculture in France annually, in great swarm- 

 years, is estimated by Le Moult at £10,000,000, the number 

 of larvae per acre being up to 150,000 in bad cases. 



vii. Cockchafer larvae, termed vers hiancs, have been dealt 

 with in France by infecting certain of them with Botrijtis 

 tenndla or Isatis densa, and then putting them into the 

 attacked field. The results were not satisfactory. Another 

 plan, adopted in 1896, for forest nurseries is to prepare cap- 

 sules full of bisulphide of carbon. These capsules are dibbled 

 in, 7 or 8 inches deep, and the gelatine gradually dissolves, 

 setting free its contents. One thousand capsules with 2| 

 grammes of the bisulphide cost25.s., and about six are required 

 every square metre. 



viii. Nothing can be done to save conifers injured by the 

 larvae, if, beside the tap-root, all side-roots have been bitten 

 off. Should, however, some side-roots remain, larch at least 

 may recover if severely pruned almost to the ground and 

 earthed-up round the roots. The pruning limits the transpira- 

 tion, and the earth round the roots prevents the drying-up of 

 the existing roots and furthers the formation of new ones. 

 These measures must be undertaken as soon as the injured 

 plants begin to droop. 



2. Melolontlia liippocastani , Fabr. 



The beetle greatly resembles the common cockchafer, but is 

 smaller, being only 20 to 25 mm. long. Prothorax generally 

 red, rarely black. Antennae and legs dark brown or black. 

 Tail shorter, more abruptly tapering, and somewhat clubbed 

 at its extremity. 



lAfe-history and economy. — In West and South Germany, 

 similar to those of the common cockchafer with which it 

 swarms, but in smaller numbers. In East and West Prussia 

 in the midst of great Scots pine-woods this species alone 

 destroys forests, the common cockchafer confining its attacks 

 to agricultural lands. It does not merely attack the horse- 

 chestnut as its name implies, but nearly all trees. The 

 larvae are highly destructive to young Scots pines, 3 to 6 years 



