November 5, 1890.] 



Garden and Forest. 



543 



Periodical Literature. 



The October issue of the Bulletin of Miscellaneous Informa- 

 tion, issued by the authorities of the Royal Gardens at Kew, 

 contains an article on a forest- plague in Bavaria, where the 

 Pine forests are injured by caterpillar of a moth (Lipparis Mo- 

 nacha). It appears that these caterpillars have attacked the 

 forests of central Europe at different times during the last 200 

 years. They make their appearance after long intervals, but 

 the destruction which they cause is serious. In Bavaria alone 

 it is estimated that the loss to the revenue from woods and 

 forests will amount next year to $200,000, and in some of the 

 forests attacked by the "nonnen," as the pest is known there, 

 the excreta from caterpillars is said to lie six inches deep. The 

 following note from the Bavarian Forest Administration on 

 this subject is reproduced from the Bulletin : 



"The Forest Department of the Ministry of Finance state 

 that the 'nonne' plague is now extended over nearly all Ba- 

 varia south of the Danube in scattered tracts. The infested 

 districts are estimated at about 22,000 acres. The fertility of 

 the insect is so great, and its numbers so enormous, that the 

 Forest Department fear that no measures of destruction are of 

 any avail. 'We stand powerless before the immensity of the 

 pest.' The insect attacks chiefly the Pine and Fir, with which 

 Bavarian forests abound, but in default of these it does not 

 despise the Beech, Oak and other forest-trees, and is even 

 known to feed on shrubs and garden plants. It never attacks 

 Corn or Wheat, and, curious to say, there is one tree, the 

 Horse-chestnut, which it will not touch. 



"The means of destruction are various. Forest-bonfires of 

 worthless wood form an easy means within reach of all com- 

 munes. The insects are attracted by the fire and are smothered 

 in the smoke, but only a comparatively small number are 

 killed. Children and boys are also sent out to destroy the 

 insects. From September to April the eggs can be found in 

 the bark and destroyed, and in April the very young caterpil- 

 lars can be more easily killed ; all these, however, are mere 

 partial measures. The only efficient general measure seems 

 to be the cutting down of whole forests when much infested, 

 in which case the remedy is almost worse than the disease. 

 One other method is used by the state, but not within reach of 

 communes, and therefore not described in the official pamph- 

 let. A large electric light is placed in the forest by night. It 

 attracts hundreds of thousands of 'nonnen' to the mouth of 

 a large funnel through which a rapid exhaust current of air is 

 forced, sucking the insects by thousands into a hole under the 

 earth, where they are buried. Even this is only a partial 

 measure, for in a forest containing perhaps a hundred millions 

 of ' nonnen' it is not much to destroy 200,000 or 300,000. 



"The Forest Department consequently fear an even greater 

 extension of the plague next year, and an even worse danger 

 is threatened — namely, that of the 'bark beetle,' which, bur- 

 rowing under the bark, is much more injurious to the wood 

 and more difficult to kill. It is always found that where the 

 forests are injured by any special cause the 'bark beetle' fol- 

 lows and attacks the injured or diseased wood in vast num- 

 bers, and this is greatly feared will be the case in 1891. Great 

 numbers of trees are being felled, but to avoid flooding the 

 market with timber and causing a ruinous fall in prices, con- 

 tracts and agreements have been entered into with neighbor- 

 ing forest-owners and the large timber-dealers by which only 

 certain quantities will be sold at a time, and prices will be 

 maintained. The yearly 'cut' in the other Bavarian forests 

 has also been much reduced." 



The following account of the "nonne" is translated from 

 the Bulletin for the Miinchener Neueste Nachrichten: 



"Just as men and beasts are from time to time carried off in 

 multitudes by epidemics, which epidemics it has not yet been 

 found possible entirely and finally to suppress by art and 

 science, and by doctors and veterinaries, in like manner the 

 trees of the foreest are now and then attacked and destroyed 

 by forest-insects. Fortunately these vanish, as a rule, as 

 quickly as they come, by the operation of natural agencies. 

 This is the only consolation we have in view of the desolate 

 condition to which many of the Pine forests of Germany, and 

 in particular of Bavaria, have been reduced by the horrible 

 devouring caterpillar, the ' nonne.' 



"Before now in earlier centuries our woods have been 

 attacked by similar calamities, and yet the German forests 

 grow green and thrive, and yield, year by year, higher rents. 

 This may serve to calm too anxious minds and to correct the 

 views of those who are so ready with their judgments, and 

 who ascribe the blame of the misfortunes which have fallen 

 on the forests solely to the forest-officials. 



" However, the present visitation has nothing particu- 



lar to do with the forest-training nor the new forest-organiza- 

 tion, nor with the style of forest-husbandry in vogue, nor with 

 the aims of modern woodcraft, for it is well known that de- 

 struction by insect plagues occurred hundreds of years ago, 

 and therefore at a time when the trees grew of themselves in 

 primeval fashion, and there was no question of forest-training 

 nor of any particular forest-husbandry. Besides this, the fact 

 is not in dispute that the destructions caused by insects are 

 much less intense in forests of mingled broad-leaved and 

 needle-leaved trees; but this money-loving world unfortunately 

 insists on quick-growing Pine forests instead of safe slow- 

 growing woods." 



The report here gives a brief account of seventeen of these 

 insect invasions with their dates, which occurred between the 

 middle of the fifteenth and the beginning of the present cen- 

 tury. Of these visitations the last one, which raged in the 

 Pine and Fir forests of Lobenstein, Schleiz, Ebersdorf and 

 Saalburg from 1794 to 1797, worked vast destruction, so that 

 the loss was reckoned at 2,000,000 cords of wood. " Bechstein, 

 in his Forest-Insectology (1818), describes the great destruction 

 caused by the 'nonne' caterpillar in 1794-97 in Vogtland, 

 Lithuania and west Russia, and gives figures which correspond 

 exactly with our present situation. Seventy-two years ago he 

 wrote as follows : 



" ' It is horrible to travel in districts where these caterpillars 

 swarm. Many thousands crawl up and down the trees. One 

 cannot take a step without treading on a number of them. 

 There is a perpetual rain of their excreta, which often lies six 

 inches deep, and being dissolved by the rain, collects in 

 puddles, which diffuse a pestilential stench. One can form no 

 idea of the magnitude and terrible nature of the destruction. 

 Fortunately, Nature herself stopped the pest through a kind of 

 dysentery which attacked the caterpillars in the beginning of 

 June, 1797. This deadly sickness was attributed to a kind of 

 mildew. The caterpillars collected together in great thick 

 clumps four to six inches across, the excreta became pale, the 

 intestines dirty, and so they died, leaving behind them a dis- 

 gusting stench.' 



"As to the measures of prevention and suppression of that 

 day, they hardly differed from those in use now. Bechstein, 

 in 1818, recommended, first, protection and encouragement of 

 insectivorous birds; second, protection of useful insects which 

 attack and pursue the "nonnen"; third, scraping the eggs off 

 the trees with brooms and scrapers with long and short stems; 

 fourth, picking off the moths, caterpillars and cocoons (in 

 1796 the Prussian district administration at Hof caused 1,838,000 

 female butterflies to be caught, and paid six kreutzers for every 

 thousand); fifth, the lighting of a number of small bonfires on 

 dark nights (for it is well known that butterflies are attracted 

 by the moonlight), and they paid in Bayreuth in 1796 for one 

 night's maintenance of fire and bringing wood five groschen ; 

 sixth, isolation of the districts attacked by broad paths and 

 ditches; seventh, cutting off in March and April of the branches 

 nearly to the vertical and burning them ; eighth, cutting down 

 of whole standing trees, and burning of the branches and bark; 

 ninth, removal of moss and litter from the forests and burn- 

 ing, if eggs or caterpillars are found therein. 



"In connection with the injury caused by the 'nonnen' in 

 this century, we may briefly mention here the extensive 

 plague of 1839 an d '840 in upper Suabia (Wiirtemberg), which 

 ravaged many hundreds of 'morgens' of Pine forest. The 

 same thing was repeated in 1855, and at the present moment 

 is appearing almost in the same spots in a very serious man- 

 ner. But the most considerable 'nonnen' pest of all took 

 place in Russia, and spread from 1845 to 1868 in a most devas- 

 tating manner over Poland, Lithuania and east Prussia. The 

 invasion in east Prussia began suddenly in 1853, in the night 

 of July 29th-3oth, and covered a superficies of about sixty 

 German square miles in the administration of Gumbinnen, 

 after it had already crossed over in 1851 and 1852 the southern 

 boundary of the administration of Konigsberg. At that time 

 the moths were driven by a storm into the sea while on their 

 way, so that the insects were thrown by the waves upon the 

 coasts for a distance of ten German miles in a bank seven feet 

 wide and six inches thick, and were used as manure by the 

 coast inhabitants. The extent of the ravages in Russia at that 

 time was 6,400 German geographical square miles, and in east 

 Prussia 600, making a total of 7,000 miles. At the very least, 

 55,000,000 Prussian cords of wood, or 185,000,000 cubic yards 

 of wood, became the prey of ' nonnen ' and bark beetles. 



"The examples given suffice to show that the 'nonnen' 

 have made their appearance in former centuries in large num- 

 bers, and have generally disappeared with equal suddenness. 

 The present catastrophe will likewise come to an end after 

 causing heavy losses, though it may possibly return many 



