148 Flies [CH. 
the grubs, but being very tenacious of life they are not 
killed unless the application is so severe that the grass 
is also killed. Heavy rolling early in the morning 
when the grubs may be on the surface kills some of 
them, and also consolidates the soil so that others 
cannot move about so freely. This is particularly 
useful when corn crops are attacked. They are eaten in 
Fig. 46. Wasps eating daddy longlegs flies. These wasps 
were destroyed in the nest. 
large numbers by rooks, starlings, plovers, pheasants, 
gulls, and moles, and to a smaller extent by thrushes 
and blackbirds. Considerable numbers of adults may 
often be found in wasp nests (see Fig. 46), and they are 
also eaten by flycatchers, rooks, swallows, and spar- 
rows. When a root crop is attacked frequent hoeing 
is useful as many grubs are killed and others are turned 
up and eaten by birds. The penning of sheep on the 
land when the pupa cases begin to force their way up 
to the surface has proved successful. 
