174 PROTECTION OF WOODLANDS. 



behind strong electric lights, and after endeavours made to isolate the crops 

 attacked by surrounding them with poles thickly coated with patent tar on the upper 

 side, had all been found only partially successful, it occurred to a young forest- 

 officer named Mayer to try the effect of putting rings of the patent tar round all the 

 steins of a young 12 to 15-year-old Spruce plantation, which was first of all cleared of the 

 lower branches for the purpose. This experiment was found to answer so well that 

 it was carried out on a much larger scale in 1891 ; and as the damage done in that 

 year was still greater than it had previously been in 1889 or 1890, it was again 

 resorted to in the present year, no less than 75,000 being spent in the Bavarian 

 State Forests alone on ringing with patent tar all the stems from the thickness of a 

 finger upwards, in whatever areas it was known that the moth had gained a footing. 

 Millions of stems may now be seen with these blackish rings at breast-height, which 

 experience has shown to be much less expensive than, and practically quite as effective 

 as, ringing at about 15 to 18 feet above the ground. By forming them at the latter 

 height, it was thought to intercept the tiny caterpillars from all the ova deposited 

 between breast-height and that elevation, but the happy efficacy of this remedial 

 measure rests on the fact that practically all the caterpillars spin down on gossamer 

 threads from the crowns of the trees to the ground before they have developed so 

 far as to lose this power of spinning, and that when they wish to re-ascend tho 

 stems, their progress is barred by the viscous band of tar, whose smell, or taste, or 

 touch they absolutely abhor ; and being unable to pass over them, they die of hunger 

 in hundreds, and on large boles often in thousands, below the rings. 



In 1892 the plague of moths has been completely stayed. Abnormally warm 

 weather early in spring induced the tiny larvse to come out of the shell earlier than 

 usual, but the cold snap which followed it prevented the Spruce and Pine from 

 throwing out young foliage, so that whilst caterpillars already below the tarry rings 

 could not ascend the stems, those above them could find no food in the shape of 

 the new flush of needles, and were physically unable to attack the older and harder 

 needles of last year, and so both sets died of hunger. But in addition to this, fungoid 

 diseases broke out amongst them, and it seems undoubted that after about three 

 years of devastation, when they occur absolutely in millions, the caterpillars become 

 constitutionally debilitated, and are extremely apt to die off even much more suddenly 

 than they increased and multiplied. 



Thousands of acres of coniferous woods, mostly Spruce, have been totally defolial 

 or so badly injured that millions of cubic feet of timber have had to be felled 

 thrown on the timber-market at extremely low prices. But it is still too early to i 

 up the account and state the full extent of the calamity due by this Spruce-moth, 

 the subsequent destruction among the remaining woods by Pissodes Tiercynia 

 Hylesinus poligraphus, Callidium luridum, and in a lesser but still considerable 

 degree, by Anthaxia quadripunctata, Bostrichus chalcographus, micrographus, auto~ 

 graphics, and lineatus, Hylesinus pilosus, palliatus, piniperda, and minor, and 

 Pissodes pini, is indirectly due solely to the ravages of the Spruce-moth, and ^vill 

 very considerably swell the total extent of the damage done. Trans. 



