DAMAGE CAUSED BY ANIMALS. 115 



2. Among Birds. 



The birds that are most useful in devouring numerous insects 

 at various stages of development include the cuckoo (Cuculus 

 canoris), which feeds eagerly on hairy caterpillars like those of the 

 Pine moth (G-astropacJia pini), that are avoided by most other 

 birds, the starling (Sturnus vulgaris), Tits or Titmice (Paridte), 

 tree-creepers (Certhia familiaris), swallows (Hirundines), and 

 most singing-birds, then thrushes (Turdidte), ravens (Corvus 

 frugilegus), the stannel hawk (Tinnunculus alaudarius), and 

 wasp-buzzards (Pernis apivorus) ; wood-peckers (Picus, vide par. 

 55). Sparrows and finches (Fringillidce), crows (Corvus), rooks 

 (Monedula turrium), and larks (Alaudidw), are only of minor 

 utility in this direction. 



All the above-named animals and birds should be protected 

 and preserved wherever the good they effect is likely to exceed 

 the damage done (by wild-pigs, fox, marten, and crows). The 

 increase of the useful birds should be assisted by Bird Protection 

 Acts, and more directly by the hanging up of nesting-boxes 

 throughout the woods. 1 



3. Among Insects. 



The useful forest insects, or the enemies of forest insects to be 

 found in the class of insects themselves, are perhaps of greater 

 importance than those found among mammals and birds. They 

 are either predatory species devouring as larvae or imagines the 

 ova, larvae, pupae, or imagines of other insects, or else they are 

 parasitic species compassing the death of injurious insects by 

 depositing their own eggs in the ova or larvae, less frequently in 

 the chrysalides or the imagines, of the others, on which the 

 maggots proceed to feed when they come out of the egg. 



Such species always occur in woodlands to a far greater extent 

 than the casual observer might be inclined to believe ; and as 

 injurious insects increase in number, so do these predatory and 



1 Since the recent calamities in Bavaria caused by the " Nun " (Liparis monacha) 

 from 1889-1892, thousands upon thousands of wooden nesting- boxes have been erected 

 throughout the woods, particularly with a view to increase the number of starlings by 

 protecting their nests and young against cuckoos, squirrels, and wild cats, &c. Trans. 



