FARM PESTS 61 



placed in the tiny wound made by the ichneumon. 

 13efore long the caterpillar will develop a " peckishness " 

 about its food, with an appetite which it cannot satisfy 

 for the other larva inside it, always careful to avoid biting 

 a vital part of its host, has to be brought on to maturity 

 When full-fed, the ichneumon larva destroys the moth 

 larva and bores its way out to pupate and emerge as a 

 perfect fly. It is thus that Nature provides the true 

 check for the Diamond-Back Moth. We shall come 

 across many similar cases of parasitism as we proceed 

 some of them hymenopterous insects like this ichneumon' 

 some dipterous hke the common house-fly. It is more 



.f" /??^^^^,*^^* ^''^''y butterfly and moth is thus 

 attended by a fateful shadow in its pMh, although they 

 have not all been identified. The attack is nearly always 

 in the larval stage, but there are actual cases of the 

 tmy egg itself being parasitized by a still more minute 

 nymenopterous enemy. 



Our concluding example is the infamous Turnip Moth 

 (Agrohs segetum) whose larva, one of the so-called 

 surface caterpillars," from the habit of hiding under 

 a clod during the daytime, works such havoc. In America 

 ^rn^J^"^'^ cut-worms " of allied species, which eat 

 around and so sever the stems of the plants attacked. 



The Turmp Moth is a long-standing and vexed question 

 m this country and its depredations extend over quite 

 a ong range of plants, wild and cultivated. The larva 

 will, in fact, eat anything succulent, but burrows greedily 

 mto the turmps wherever they can be found. It betrays 

 the cut-worm characteristics in the flower-garden 

 e pecially among the asters, where the long-suffering 

 gardener will be grieved to see his most prized plant! 

 unaccountably wither up and die. A glancHt the stl 



or tL on/ ^^T'-uT '^' '""'^ ^^ ''^^^^ '^^ --"«e, 

 and th. ^''wf will be completely gnawed through 



^th 1 lifFl ^".' ''"^'^- ^"* ^^^ «^^r°^^d them 

 with a httle ring of soot and alum in advance 



