192 PROTECTION AGAINST INSECTS. 



at the foot of their fruit trees to secure them against insect 

 attacks. 



. It is therefore necessary to protect ants in every possible 

 way, though unfortunately their increase is greatly prejudiced 

 by the search for the so-called ants' eggs for the purpose of 

 feeding young pheasants, etc. This also deprives useful forest 

 birds of a portion of their nutriment. Henschel* states that 

 in the Austrian Alps the sale of dried ants' eggs of Formica 

 rw/<7, L., amounts annually to 50 70 hectolitres, which means 

 from 96 to 134'5 million ants, for 1 hectolitre contains about 

 1,920,000 pupae. 



In Kussia also the business is carried on vigorously, the 

 right of collecting pupae being leased on certain areas, one 

 man having collected 18 worth in 1J months. 



The damage wJiich ants occasion by constructing their 

 galleries and nests in sickly trees, or by eating sweet fruits, or 

 by burrowing into planting-mounds is trifling in comparison to 

 the good they effect. 



As representatives of the family the following may be 

 mentioned : 



Formica rufa, L., the common wood-ant, makes great 

 heaps of needles in coniferous forests, chiefly in those of 

 Scots pine. 



Lasius fuliginosus, Latr., in old trees and stumps of oaks, 

 poplars, willows, etc. 



Myrmica r libra, L., very common in forests under stones, 

 sods, bark, etc. 



There are species of ants which by hollowing out nests in 

 standing trees, or by gnawing plants, or disturbing mound- 

 planting, are injurious. These are Campanotiis herculaneus, 

 L. ; C. lignipcrdus, L. Both species hollow out large'stand- 

 ing and felled stems of conifers, chiefly of spruce and silver- 

 fir, to a height of 30 feet from the base of the trees, in a 

 manner that is concentric with the annual rings, so as to 

 render the timber unserviceable. Woodpeckers frequently 

 increase the extent of the damage, which has also been 

 observed on oaks, limes, and robinias. Lasius flavus, Latr. 

 injures young plantations of spruce, silver-fir, beech, ash, 



* Centralbl. iUr das ges. Forstw., 1876, p. 160. 



