76 
MUSTARD. 
nearly allied, they would be found during winter under anything that 
would protect them. 
In the spring (it is stated by Kaltenbach) the beetle is to be 
found in damp places on brook lime and on the bitter cress, 
Cardamine amara, and the grubs are to be found feeding on the under¬ 
side of the brook lime leaves. When full fed the grubs leave the 
plant and turn to chrysalids in the earth, but without spinning any 
kind of shelter for themselves, and the chrysalis state lasts only four¬ 
teen days. The beetles, of which a figure is given above, are of a bright 
blue or green, with the underside, horns, and feet black. Two broods 
of caterpillars have been observed, the first in May and June, the 
second in September.* 
The only method at present found of real service in keeping down 
the multiplication of these beetles appears to be a change of crop, 
which may remove their chief food, but removal of the Mustard straw, 
and burning it instead of allowing it to be stored for shelters or rough 
roofing, is recommended, and burning all standing rubbish round 
fields as well. 
The methods of prevention noted will be observed to turn on the 
same principles as those brought forward in 1881 regarding prevention 
of Turnip Fly—namely, to clear out the pest by removing its food; 
to run the crop through moderate attack by vigorous growth; and 
also as far as possible to get it on so as to be at a different time to 
when the first burst of attack may be expected in full force. 
No mention is made of any dressings such as are considered by 
many Turnip growers to be serviceable in checking attack having been 
tried whilst the Mustard is still young enough to allow of the applica¬ 
tion ; nor of whether any caustic dressing, such as fresh gas-lime, is 
used to destroy the beetles that might be above or near the surface 
after a Mustard crop; nor yet of whether any clearing of the plants 
in or by the ditches, which afford shelter in winter and food in spring, 
as hollow reeds, water-cress, brook lime, bitter cress, shepherd’s 
purse, &c., has ever been found practicable on a scale to be of service 
to the crops close by. Any information on these heads would be very 
acceptable for publication. 
* See ‘Die Pflanzen-feinde,’ by J. H. Kaltenbach, p. 26. 
