178 PROTECTION OF WOODLANDS 



tinguishable by having only one point at the lower extremity, 

 and by being somewhat less in size. 



The time of the swarming of the moths is during May and 

 June, when the males may be noticed flitting about during the 

 daytime, although like other moths their natural time of activity 

 is towards night. After impregnation, the female deposits her 

 bright-green ova on the needles of the Pine, near the summit of 

 the crown, and on the foliage at the extreme end of the side- 

 shoots. The tiny caterpillars make their appearance about the 

 beginning of July, and at once begin to feed, commencing by 

 only gnawing the needles slightly, but afterwards biting them 

 through about the middle, so that the upper half falls to the 

 ground, whilst they devour the lower portion remaining. Thus, 

 directly the opposite takes place here of what occurs in the case 

 of the Spruce-moth, for whilst the " Nun " carries on its destruc- 

 tive work from below upwards (i.e. centrifugally), the Pine span- 

 worm devours the foliage from above downwards (i.e. centripetally). 

 The spanworms or caterpillars have the power of spinning 

 themselves down to the ground on gossamer threads, and often 

 let themselves down to the ground in this way before entering 

 the pupal state of rest. 



The chrysalid metamorphosis takes place about October, either 

 under moss or on the surface of the soil, the caterpillars often 

 lying extended on the ground for some time awaiting the final 

 change of skin, during which they enter the pupal state. The 

 chrysalides lie scattered about the whole of the area that has 

 been infested with the spanworms, and do not necessarily confine 

 themselves merely to the extent overshadowed by the crowns 

 which they have been feeding. 



The Pine spanworm or Bordered white moth has often 

 known to commit extensive devastation in certain localities ; 

 here again, although it may also be occasionally found on other 

 species of trees, it is young pole-forests of Scots Pine which most 

 of all suffer from its attacks. Its power of inflicting injury on an 

 extensive scale is diminished by the facts that, in the first place, 

 it does not commence feeding till the new spines or needles are : 

 completely developed, and the young buds for the following yearto 

 foliage are already actually formed, and that, in the second ]>l;i<r, 

 experience has hitherto shown that two bad years of spanworms 

 occur only very exceptionally in succession. 



