Pinus 



(205 ) 



Pinus 



trouble on the Continent ; in Britain it is compara- 

 tively rare. Agaricus raelleus is a common foe 

 and attacks the Pines. 1'eriderraium Pini occurs 

 upon both branches and leaves, but while the 

 branches suffer severely the leaves do not appear 

 to bo much the worse. 



The premature fall of the leaves or " needles " is 

 brought about by the action of several species of 

 Hysterium, of which Pinastri is common to the 

 Scotch Fir. 



KETJNIA), Gall Mites (see PHYTOPTUS), Sawflies, 

 and Aphides (see CHERMES), there are many others 

 comparatively less common but very destructive 

 where they are in any numbers. Pissbdes Pini and 

 notatus are small beetles which gnaw the bark 

 from the young shoots, a flow of resin resulting. 

 Hylobius Abietis feeds upon the bark of the young 

 shoots of the Scotch Fir and several other Conifers ; 

 it is most destructive to young trees, and in plant- 

 ations where cut down branches are allowed to lie. 



Photo : Cassell & Company ^ 



PlNUS MUKICATA {see p. 206). 



Further details concerning these fungi will be 

 found under the names of the various genera. It 

 may be well to point out here, h&wever, that the 

 methods of combating these fungi must, from the 

 nature of the trees involved, be more preventive 

 than curative. Spraying big specimens is out of 

 the question. General cleanliness, the removal anil 

 destruction by fire of badly attacked or dead 

 branches and trees, and fallen needles in the case 

 of Hysteriurn, is an important item. Some author- 

 ities have recommended the cutting of trenches 

 round the trees, outside the spread of the roots, to 

 prevent the passage of the mycelium of root fungi 

 through the soil from infected to healthy trees. 



Equally important are efficient soil drainage 

 and free circulation of light and air amongst the 

 plants. Cold, stagnant soil and crowded planta- 

 tions favour the production of weak growth 

 predisposed to succumb to fungoid attacks. 



Insect Enemies. Special hints will be given 

 under the names of the various genera of insects 

 that attack Pines. In addition to Cockchafers, 

 Mole Crickets, Pine Bud and Shoot Moths (see 



The most injurious of the Moths are the Pine 

 Beauty (Trachea piniperda), the Bordered White 

 Moth (Fidonia piniaria), and the Carpet Moth 

 (Thera firmaria). The larvae of a few species of the 

 Tortricina live between the needles of some 

 Conifers, but as a rule they are not in sufficient 

 numbers to do much harm. Shaking the branches 

 of larva-infested trees and destroying the larva? 

 which fall is sometimes practicable, but it is only 

 in the nursery beds and on the young plants that 

 the various washes employed in the subjugation of 

 insect attacks can be brought into play. 



Several species of Pine-bark Beetles do injury, 

 Hylesinus ater, H. opacus, Tomicus bidentatus and 

 T. Laricis are a few ; their larvae burrow in the 

 bark, and have been known to severely cripple 

 choice specimens. H. piniperda bores into the 

 young shoots, eating the pith therefrom, and 

 these twigs subsequently die. As the beetles 

 frequently lay their eggs under the bark of cut off 

 branches, tree stumps, and brushwood, a little of 

 this material may be utilised as a trap and, after 

 it has been allowed to lie for a few weeks, should 



