336 INSECTICIDES, FUNGICIDES, AND WEED KILLERS. 



of a gou^^e 1 centimetre (;: inch) in diameter the workman widens 

 and enlarges each hole, which is hidden in the folds of the bark 

 and under the moss of the lichens, but the presence of which is re- 

 vealed by detritus resembling moist sawdust. He cuts the edges 

 neatly, and quickly introduces into the hole a small hook, by means of 

 which he draws out the detritus which blocks up the entrance to the 

 burrows. The orifice being cleaned and in perfect communication with 

 the burrows, the workman introduces, by means of a small needle, 

 taking care not to press them, two or three plugs of cotton previously 

 steeped in benzene. He forthwith closes the hole by means of a plug 

 of rather stiff Eoman cement, which he applies with a small trowel 

 in such a way as only to penetrate into the hole to a small depth and 

 to cover the edges with several centimetres of cement. The latter 

 hardens rapidly and the hole is hermetically closed. The benzene in 

 volatilizing fills the burrows with its vapours and asphyxiates all the 

 creatures living therein. When the button which forms round the 

 wound has repulsed the cement, the odour still suffices to keep off 

 insects until the wood recloses of its own accord. An inspection every 

 fortnight after applying this process assures the destruction of all the 

 generation of the preceding year. The trees so freed do not suffer from 

 the treatment, heal rapidly, and regain their vigour. 



Cossics ligniperda, L. (the goat moth). — The process described for 

 exterminating the larvae of the Saperdas may be successfully used foi- 

 that of the Cossus. To prevent the females from laying their eggs on 

 the trunk, Truelle advises to coat it with a concentrated solution of 

 green vitriol, or with a mixture of cow-dung and clay. 



Zctizera Aesculi (the wood leopard moth, horse chestnut Zeuzera) ; 

 Trocliylium apiforme, L. — The caterpillars of these two butterflies 

 are combated like the larvae of the Sapei-das. 



Agrotis segetiim (the common dart moth). — According to Eitzema 

 Bos, the grey-worm is exterminated by benzene in the same way as 

 the white-worm and with full success. The caterpillars of an allied 

 species, Agrotis valUgera, very injurious to pine-trees, are exterminated 

 in the same way. 



Conchylis ambignella, Hubn. (cochylis of the vine) ; Endemis 

 hotrana, Schiff. (eudemis or tortrix of the vine). — The Italian Minister 

 of Agriculture recommends an emulsion of soft soap 3 per cent, alcohol 

 0'5 per cent, benzene 1-5-2 per cent. Debray obtained good results 

 with this emulsion. 



Lojms sidcatus (Grisette de la Vigne, Margotte). — Benzene 

 emulsions are used as sprays, according to Pratigeon, for the destruction 

 of the larvae of this bug at the time when they are still on the charlock 

 and groundsel at the foot of the stems. The adults are thus prevented 

 from getting on the vines. 



Tipula oleracea (crane-fly, known in England as gaffer longlegs 

 and in Scotland as daddy longlegs). — The larvae, injurious as much to 

 the roots of strawberries as to salads and spinach, may be destroyed 

 by shallow injections of benzene into the soil. It suffices that the 

 injections be 1 centimetre from the plant, that they do not hurt it. 



Tingis Pyri (tiger beetle of the pear-tree). — According to Taschen- 



