INSECT INJURIES. 481 



been commonly applied to this form of disease. If left in 

 the ground, decomposition speedily ensues, and other in- 

 sects, delighting in diseased vegetable tissues, then assist 

 in completing its destruction. Amongst these may be 

 named the well-known millipede, the Polydesmus com- 

 planatus, and a centipede, the Scolopendra electrica, 

 which frequently is found with it in the soil, always ready 

 to attack any of our root crops which have been, injured, 

 either by disease or by insect attacks. 



The caterpillar of a beautiful butterfly the Papilio 

 machaon, or "swallow- tailed butterfly" is found feeding 

 on the leaves of the carrot and other allied species about 

 the end of June or July, where the eggs had been de- 

 posited by the female about a month or six weeks 

 previously. This insect, however, like many others we 

 could name, appears to become more scarce every year, 

 as draining and improved cultivation effects a physical 

 change on the surface. Formerly it was abundant in dis- 

 tricts where it now would be searched for in vain, its pre- 

 sent range being apparently confined to the fen districts 

 of Lincolnshire, Huntingdon, and Cambridgeshires. 



When grown for seed the umbels often appear distorted, 

 and a number of fine small vegetable galls are found 

 attached to them, the result of the punctures of the 

 "carrot gall-fly" Callimome dauci; and as the flower- 

 heads become more matured they are subject to the 

 attacks of three other moths the "common flat-body 

 moth/' Depressaria cicutella, the " purple carrot-seed flat- 

 body moth," D. depressella, and the "gray carrot-blossom 

 flat-body moth," D. daucella each of which is capable 

 of inflicting great injury on the seed-vessels, and of thus 

 materially affecting their yield. The flowers and capsules, 

 and even sometimes the leaves, are eaten off by them, the 

 head being enveloped in a silk-like web, in which they 

 remain and change to the pupa state. Happily the cater- 



