DAMAGE CAUSED BY ANIMALS. 173 



it is at best only a sort of half -measure. They are easily killed 

 near the base of the stem by the use of a leather flap tied to the 

 .end of a rod or stick, whilst a long thin pole with a thick knob of 

 cloth at the end is the best way of getting at them if seen at 

 some height above the ground, and beyond the ordinary reach 

 with the flapper. Altum recommends the smearing or soaking 

 of the latter with a solution of patent viscous tar. The principal 

 drawback of this method is, that the whole of the clusters of ova 

 are not all hatched at the same time, so that some schools or 

 colonies appear earlier, and others only later, whilst a constant 

 repetition of the process of destroying them is practically out of 

 the question. 



The destruction of the larger caterpillars, as well as of chrysa- 

 lides and of moths, is always accompanied with difficulties, and on 

 the whole not particularly satisfactory, although at the same time 

 the somewhat lazy female seated quietly on the stem is easily 

 discernible and approachable, and can easily be killed or collected 

 during the daytime throughout the period of swarming. 



The number of the natural enemies of this insect, and especially 

 of the hairy caterpillar, is comparatively small, as also in the case 

 of the Pine-moth ; but during the winter very large numbers of the 

 ova are devoured by many kinds of birds, particularly by tomtits, 

 whilst predatory species of insects, principally Ichneumonidw and 

 Tachininte, also annihilate many caterpillars. Like the Pine- 

 moth, this Spruce-moth is comparatively insensible to changes in 

 the weather and to climatic influences generally. But, at the 

 same time, it is usual for its ravages to cease also after the third 

 year, when the caterpillars, somewhat degenerate by that time, 

 and less both in size and vigour, die off in large numbers ; and 

 recently the opinion has been strongly expressed, that as annihi- 

 lative measures seem to be practically of little effect, it is per- 

 haps better not to spend money and time on them, but to leave 

 the matter for nature to assert its proper balance again. 



Note. As the work of which this is a translation was published in 1889, before 

 the recent calamitous devastations throughout Bavaria and Western Austria, begun 

 in 1888, had anything like reached their culminating point in 1891, it may be per- 

 mitted to me to briefly indicate the exterminative measures which the experience 

 then won has proved to be most effectual. After the remedies previously held in 

 repute and above referred to had all been tried during 1889-1890, (including collection 

 of ova, crushing of young caterpillars whilst still in schools or colonies, and later on 

 collection of the full-grown caterpillars and chrysalides, and cutting and burning all 

 undergrowth covered with pupae), after experiments made with exhausters worked close 



