INSECT RAVAGES. 167 



The wbite willow 1ms boon stripped of its leaves very often by the 

 larvte of the Nematus ventrulis (Say). Its antidote is the dust of white 

 hellebore sifted upon the leaves. 



The inealy bug, or white aphis, sometimes infesting the leaves of the 

 white pine, may be killed off by syringing the trees with soap-suds of 

 whale-oil. 



RAVAGES OF THE SCOLYTES. — EEMEDY PROPOSED BY M. ROBERT. 



lu many parts of Enro])e the elms have suffered very greatly from 

 a minute beetle, the Scolytes destructor, which, by mining its galleries 

 through the bark, have by their multitude, and the abundance of their 

 work destroyed great numbers of tine trees upon public grounds in 

 cities. This insect prefers full grown trees to the younger class, and 

 those somewhat enfeebled by age rather than trees in full health, A 

 remedy has been practiced with success by Dr. Eugene Robert, in Paris 

 and elsewhere, but this is not api)licable in a large way in forestculture 

 on account of its expense, although it may at times be applied to the trees 

 in avenues and public parks. It consists in removing the outer por- 

 tions of the bark, down to the living part, taking care not to wound the 

 latter, and in carefully cleaning out decayed and unsound spots when- 

 ever found. The operation should not be performed in warm weather, 

 and should include the trunk and larger branches, the smaller ones 

 being simply scarified longitudinally. Trees thus treated present an 

 unsightly ai)i)earance for some months, which is obviated bj- painting 

 them with coal tar containing yellow ochre enough to give a natural 

 brown tint. It is claimed that trees thus treated acquire new vigor of 

 growth, and that as with the cork oak, they seem to thrive better with- 

 out the outer bark than with it. ^ 



INJURIES TO YOUNG PLANTATIONS BY GRASSHOPPERS. 



Plantations of trees for ornamental purposes and ibr timber growth, 

 in the States west of the Mississippi have snttered in recent years, in 

 common with agricultural crops generally, from the ravages of grass- 

 hoppers, which, eating off the leaves and the bark of 3"oung twigs, have 

 often destroyed young trees, and seriously affected the growth of larger 

 ones. With the exception of the red cedar, no kinds have wholly 

 escaped; but in cases where the supply of foliage was abundant, these 

 insects have shown preference to some and have left others almost intact. 

 The willows and cotton woods have usually suffered most, while thecoui- 

 iers and the box elder have olten remained uninjured. It is also ob- 

 served that trees after four or five years' successful growth, acquire a 

 power of endurance sufiicient to carry them through with the loss of 

 only the younger twigs, and that they will put forth new branches to 



its ^vbolesale desriictiou by borers a few years since. He liad noticed tliat tbe insect, 

 baviug liaisbed its ravages, bad disappeared, and tbat tbo young suckers from old 

 trees bad remained untoucbed. He was inclined to believe tbat, sbould it reappear in 

 Illinois, it would ba less injurious tban before. Tbis disappearance of noxious insects 

 bas been repeatedly observed in regard to tbose infesting otber plants, and aftbrds 

 ground of encouragement in respect to tbe locust tree. — {Trausactions of Illinois Horti- 

 cultural Society, 1872, p. 244.) 



^Bulletin de la Soc. Botaiiique de France, March 27, 1857. Saturday Bevieiv. (Lond.) 

 January 8, lt!59. P. 38. Les Eavagevrs dcs Forvts et des Arhres d'Aligucment, by H. de la 

 Blancbere and Dr. E. Robert. Paris, r)tb ed. 1876. Tbe second part of tbis work, by M. 

 Robert, describes bis method very fully, as practiced under bis direction as inspector 

 of idautations iu tbe city of Paris. 



