MANGOLD "leaf-blister*' MAGGOT. 87' 



ravages ? Tf it were on the leaf instead of inside, we might have a 

 better chance of getting rid of them." 



Still the attack, so far as letters sent to myself indicated, was worst 

 in the west, and amongst communications sent, one from Mr. Geo. 

 Boss Divett, sent from Bovey Tracey, Devon, on the 16th of Jime, 

 noted the infestation as having recently appeared in that neighbour- 

 hood, although it was not doing so much harm as in the parishes of 

 Manaton and North Bovey, which lie high, and in which presumably 

 the plants are small. " With us on lower ground the mischief is not 

 so great. The maggot apparently eats its way out of the blister with- 

 out reaching the more vital parts of the stronger plant, which is not 

 seriously injured." On the 20th of June, another letter from the 

 neighbourhood of Truro, mentioned the attack as being " vei-y rife in 

 this neighbourhood this season," and begged for information thereon. 



The preceding notes are given just to show the serious amount of 

 damage occurring from the maggot, also how early in the growth of 

 the young plants (even when the leaves are only about an inch long) 

 it is possible for the pest to strike them, and also how, from the 

 withering and destruction of the leafage, the early attacks are at times 

 attributed to eifect of late frosts, and consequently no remedial 

 measures adopted. I have also (though I usually remove anything of 

 a personal nature from communications before publication) in these 

 instances left the requests for information appended, as these show the 

 general need (and also the desire) for more information regarding this 

 attack. 



Also as there is nothing objectionable in slightly altering a popular 

 name in order to make it more clearly descriptive, I have added the 

 word " blister " (see heading at p. 83) to the name " Leaf Maggot," as 

 thus under the name of " Leaf-blister " Maggot attention will be drawn 

 to the characteristic of the maggots being found not simply within the 

 leaves, but within the blisters, or patches, which their destructive 

 operations give rise to. These may easily be distinguished by the 

 altered colour of the skin of the leaf. At first the patch is small and 

 hardly altered in colour, gradually it increases in size, and the dead 

 skin becomes whitish or variously discoloured, till in bad attacks the 

 destroyed portions of the leaves, whether the blistered parts, or the 

 parts destroyed by these injuries cutting off passage of the sap, become 

 dead and brown. 



The maggots do not by any means always show through the blister- 

 skin to general inspection, but if the leaves are held up against the 

 light they will probably be very easily observed, or the gentle appli- 

 cation of a finger and thumb, so as to feel where the slight lump of the 

 maggot presence may occur, will soon show their whereabouts 



From the 20th of June no further communications were sent as to 



