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MUSTARD. 
Mustard Beetle ; “ Black Jack.” Phaeton betiola, Linn. 
Ph^don betum:. 
Mustard Beetle, nat. size and magnified.* 
Attack of Mustard Beetle, commonly known as “ Black Jack,” lias 
become such a frequent and serious evil, in the course of the last ten 
years or so, that it needs a thorough investigation. 
The first observation (so far as I am aware) of remarkable appear¬ 
ance of this pest was in 1854, when Prof. Westwood, in reply to 
enquiry regarding beetles sent him for examination, stated:—“The 
little beetles which are attacking the White Mustard crops in the Fens, 
near Ely, are the Chrysomela ( Phaeton ) betula. Such a fact has not 
previously been recorded .” 
Attack is mentioned as having been bad in that year, but not again 
till 1877, when they or an almost similar kind were reported from 
Wisbech (in the ‘Chamber of Agriculture Journal’), as doing great 
harm to Mustard and other vegetables; and a grower of Coleseed near 
Littleport estimated his losses through the ravages of “ Black Jack ” 
at £1000. 
In 1878, Mr. Marshall, of Ely (in a paper published in the 
‘ Gardeners’ Chronicle ’ for Sept. 14th), mentioned that the “ Mustard 
Beetle” had again been doing much injury to the White Mustard, and 
other Brassicaceous crops, in the Fens at and near Ely, and notes 
that, though giving the preference to White Mustard, he had seen 
them that year on Turnips, Coleseed, and Kohl Rabi, and also on 
Charlock; likewise (which may be well worth bearing in mind) that 
* The grub figured above by John Curtis was considered by him to be probably, 
but not quite certainly, that of the Mustard Beetle, figured accompanying. I 
should be greatly obliged if in the course of next season some of my correspondents 
would favour me with some grubs from Mustard under attack, so that we might 
secure a figure and description. 
