278 PROTECTION AGAINST INSECTS. 



where the insect is common south of Scotland, a single 

 generation is more usual, the larvae which hatch in May or 

 June becoming full-fed at the end of July and remaining in 

 the tree throughout the winter. 



c. Relations fo tlie Forest. 



The beetle attacks old and young elm-trees, and sometimes 

 also the ash. 



The mother-gallery is broad, short, ascending and vertical, 

 about 2*5 mm. broad, and with 1 to 2 air holes. The second- 

 ary galleries ramify from it at right angles in a fairly regular 

 manner, lie close together, are long, sometimes extending for 

 more than 4 in., gracefully curved, and somewhat broader at 

 their ends than the primary gallery. The pupal chambers 

 when the bark is thin are excavated partly in the sapwood. 



This beetle especially attacks elms in the neighbourhood of 

 large towns ; thus in 1842, elms in Eegent's Park were infested, 

 and in 1870, many elm-trees that had been weakened by a 

 raising of the ground water level were killed in Berlin. 



d. Protective Rides. 



As a preventive measure, elms in avenues, parks, etc., may 

 be smeared with Leinweber's* composition. 



All stems attacked by the beetle should be felled, beginning 

 in July, and the bark burned. Trees that have been felled 

 may be used as traps, and treated accordingly. 



2. Scoli/tus intricatus, Ratz. 



a. Description. 



Beetle, 3 4 mm. long; black, with the elytra, antennae and 

 legs, pitchy-red, or brown ; the former with close rows of 

 punctures, the interstices 'narrow, closely wrinkled, the suture 

 depressed round the scutellurn ; abdomen unarmed. 



* 5 Ibs. tobacco, mixed with pailful of hot water, are kept hot for 24 hours ; 

 the water is then squeezed out of the tobacco and mixed with \ pailful of 

 bullock's blood, 1 part of slaked lime and 16 parts of cow-dung. This is kept 

 in an open tub and stirred once a day, and used after fermentation has set in. 

 The rough bark, moss, etc., is trimmed off the tree, and the latter painted with 

 the mixture for three successive days, until a crust is formed which the rain 

 will not wash off. 



