102 First Report on Economic Zoology. 
predaceous insects as it they would do all that is required to check 
an insect pest. In a few cases predaceous insects have done 
enormous good, under abnormal conditions, but in a state of nature 
they never appear in sufficient numbers to make any impression 
until the pest in question has increased to such an extent that the 
harm is all done. The introduction of new predaceous forms is, 
•however, always worth trying, as now and again good has resulted, 
as seen in the case of the leery a scale and Vedalict cardincdis. 
When people commence to talk of stopping spraying for Aphides 
or scales because the beneficial parasites are killed also, it is sufficient 
evidence they know little of fruit-growing or the fruit grower’s 
troubles. 
In the Tipulkke we find scarcely any record of insects that 
destroy either larvte or adults. Curtis mentions Ichneumons as 
attacking the larvae, but says no more. Although I have bred large 
numbers from different parts of Britain I have never come across a 
parasite, with the exception of a single ? Tcichina, sp. (?) that appeared 
in a cage of T. olcracea. Numerous birds, however, feed very largely on 
these insects, not only upon the larva3, but also upon the adult flies. 
Amongst those birds which are great “ leather-jacket ” destroyers 
are the following : the Book, the Starling, the Peewit, various Gulls, 
the Pheasant, and, to a lesser extent, all the Turdidce, or Thrushes, 
and Blackbirds. Enormous numbers of these larvie are devoured in 
autumn, winter, and spring by the three former birds, and the 
pheasant’s crop may frequently be found full of them. The decrease 
ia the number of Peewits has been marked by a corresponding 
increase in this pest as well as in the Wire-worm. All these birds 
should be encouraged, not only because of their destroying “ leather- 
jackets,” but other pests as well. 
The adults are devoured by the Spotted and other Fly-catchers, 
by the Swallow, and even by the Sparrow. The Book also devours 
large numbers as they are ovipositing in the fields. Poultry also do 
much good, for they feed whenever opportunity occurs upon both 
larvse and adults. These birds all do good because they are always 
present and are constantly feeding. They are often attracted in greater 
numbers when hosts of insects appear, but even when normally present, 
by devouring these and other pests before many of them have done 
harm, they do inestimable good, whilst on the other hand parasitic 
and predaceous insects come too late. 
Moles also feed off leather-jackets, and do far more good than 
harm even in pasture land, where their “ heaps ” cause some 
inconvenience. 
