170 PROTECTION OF WOODLANDS. 



afterwards changing into brown with a bronzy shimmer, lies 

 within a very flimsy cocoon, consisting of merely a few dirty 

 yellow threads spun between the fissures of the bark on the lower 

 portion of the stem, or among the needles on the branches and 

 twigs, or on underwood or brushwood. 



The time of the swarming of the moths is about the end of 

 July or the beginning of August, or perhaps somewhat earlier 

 during dry years. During the day, and especially when the 

 weather is dull, they usually cluster about the lower portion of 

 the boles, whilst in bright sunshine the males in particular keep 

 fluttering about and revelling in the enjoyment of the brightness 

 and warmth. But, like most moths, their normal time of lively 

 motion is towards dusk, when they either flit about, or run up and 

 down the stems, seated upon which they enter in copuld. 1 



After the course of a few days the ovi-deposition takes place, 

 the eggs being at first of a rose colour with bronzy shimmer, but 

 afterwards changing to a greyish brown with mother-of-pearl 

 lustre. The female moth lays her eggs beneath the scales of the 

 bark, and always under some sort of protection. When the insect 

 does not swarm in large numbers, the ova are mostly deposited on 

 the lower portion of the stem, usually within about fifteen feet 

 from the ground ; but when there are enormous flights of moths, as 

 during the calamitous devastations of the Spruce tracts of Bavaria 

 and Western Austria in 1889-1891, they cover the whole of the 

 stems from top to bottom. 2 One female can deposit as many as 

 150 to 170 ova, which are mostly laid in clusters of 20 to 50, though 

 sometimes all are deposited in one patch or nest. 



Although in four weeks the larva becomes fully formed within 

 the ovum, the tiny caterpillars hibernate within the shell, and only 

 make their appearance in the next spring during April, or not 

 until May should the weather be unfavourable. After issuing 

 from the ova the young caterpillars remain for several days 

 collected together in clusters or schools on spots varying in size 

 from what might be covered by a penny to what the hand could 



1 It is worthy of note that the numerical relation of sexes has been found during 

 the recent immense swarms in South Germany to be- 70 % male and 30 % fVin;ili', 

 evidently a provision of nature to make the impregnation of the latter a matter of 

 almost absolute certainty. Trans. 



2 " In 1890, on large individual steins, 30,000, 50,000, and even 90,000 eggs \vi-re 

 found in the Ebersberg Park, and recently as many as 200,000 were found on one 

 btem in the Perlacher Park." Nitsche, " Die Nonne," 1892, page 8. Trans. 



