Chapter 17. 
BENEFICIAL ANIMALS, &c. 
Birds. The Testacella Slug. Earthworms. Centipedes. Bene- 
ficial Insects. The Isle of Wight Bee Disease. Literature bearing 
upon Economic Zoology. 
Beneficial animals are on the whole less widely known 
than injurious species and, unlike the latter, they should 
be encouraged so far as may be possible and under no 
circumstances be destroyed. BIRDS (1, 2) occupy a very 
high place as benefactors of the farmer and _horti- 
culturalist. There are a number of kinds which cause 
litthe harm, and are in many cases, directly beneficial. 
Among these may be cited the Fieldfare, Hedge Spar- 
row, Wrens, Long-tailed and Coal Tits, Wagtails, 
Pipits, Swallow, Martins, Swift Cuckoo, Plover, and 
many others. Tits, for instance, are particularly partial 
to Scale Insects, as well as Aphides and other Insects. 
The Willow Wren devours large numbers of various In- 
sects, and Newstead records one whose crop was filled 
with larvze of the Winter Moth, another with Aphides, 
and three other individuals contained large numbers of 
Fly Maggots. Pipits, the Cuckoo, and Swift are also 
prominent devourers of Insect life. Occasionally, how- 
ever, one or other species may be observed devouring 
fruit, the Mistle Thrush, for instance. but I believe in 
such cases the small amount of harm they cause is neglig- 
able compared with the benefit they confer. In this 
country much could be done along Continental lines to- 
wards encouraging beneficial Birds, especially by means 
of nesting-boxes, which help to ensure their presence in 
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