Reports to various Correspondents. 67 



Most of the caterpillars have pupated by the late autumn, but some 

 do not do so until the spring. They may even be found in cabbages 

 during the winter. 



PlIEVENTION AND EeMEDIES. 



1. Destroy all chrysalids when digging the ground in winter — if 

 large areas of cabbage have been attacked it would be well to turn 

 poultry on the land. 



2. Cabbages may be dusted with gas lime that has been exposed 

 to the air for three months or so ; the lime runs down into the 

 cabliages and makes them obnoxioiis to the larvte and does not harm 

 the plants. 



Cabbage Root Fly. 



{Phorhia brassicw, Bouche.) 



Broccoli plants sent by the Eev. S. N. Tebbs, of Hillside, 

 "Westbury-on-Trym, were badly attacked by the Cabbage Eoot Fly, 

 the maggots of which tunnel in all hrassicm in various ways. Mr. 

 Tebbs writes that " some of the plants have been blown out of the 

 ground by the late winds, so much have their roots been weakened 

 by this pest." 



In a further letter, Mr. Tebbs states that they had tried soaking 

 the infected plants in paraffin and tobacco for hours, but these 

 seemed only to make the grubs livelier. 



Specimens were also received from the Board of Agriculture 

 {vide page 182). 



Growers of cabbages, cauliflowers, early kale, etc. frequently com- 

 plain of the presence of white grubs or maggots destroying their 

 plants. That these grubs are of more than one species is well known, 

 but the greatest injury is done by a single species, the Phorhia 

 hrassicse of Bouche (Fig. 9). 



Where cabbages are frequently grown on the same land this pest 

 is nearly always present, and in many cases has steadily increased 

 under such favourable circumstances that the growth of the plant and 

 its allies has had to be entirely given up. It is no new pest, for 

 Bouche, who described it in 1833, wrote that " it often destroys 

 whole cabbage fields." In fact, since the beginning of the last 

 century, it has been recognised as a serious pest in many European 

 countries. In recent years it has also caused much harm in North 

 America, where its life-history has been worked out in detail by 

 Professor M. V. Slingerland. 



There are not only records of its attacking cabbage and its allies, 



F 2 



