280 
Mustard Beetles. 
The observations regarding direct measures of cultivation all 
agree in the importance of thoroughly-prepared and well- 
manured soil, for the most part cleaned from weeds by summer 
fallowing, but sometimes as a succession to broken-up grass, 
in which case the customary freedom of mustard from wire* 
worms would be an additional reason for saving this crop. But 
beyond this, and looking to the fact established by last year's 
observations that serious mischief to mustard in its early stage 
is caused by the common turnip-flea beetle, it occurs to me 
whether some of the more special treatment, used by our best 
turnip-growers to counteract the ravages of the flea-beetle on 
the seed leaves of turnips, might not be equally useful in saving 
mustard.* 
Temporary discontinuance of Mustard-Growing a means of 
clearing infected Districts. — Where a district has become infested 
by the mustard beetle the only sure method of getting rid of 
the insect is considered to be the combined action of the farmers 
not to grow mustard for a time ; or, where the attack is less 
widely spread, to cease growing the crop for a while on infested 
farms. 
This point (of discontinuance) is very strongly urged by the 
reporters. To be a complete cure, it is also desirable to dis- 
continue the growth of cabbage and other allied plants on which 
the beetles feed, though the following observation shows that 
this is not essential for general practical benefit : — 
" The only thing to be done when a farm becomes infested with the pest is 
to discontinue the growth of mustard fur a few years. This has been found 
to answer. Though the insects live on other plants they constantly diminish 
in numbers, and almost entirely disappear in the course of two or three years 
if there is no mustard in the immediate neighbourhood." — W. C. L. 
5. What manures have been found serviceable ? Is gas-lime 
used ? 
Superphosphate of lime, and dissolved bones, and " any rich 
manure." Artificial manures are necessary to secure a crop on 
* In my reports published in 1881 regarding methods of cultivation found 
most suitable for pushing on a healthy rapid growth of the turnip-plant, and so 
carrying it from under the power of tlie " fly," great stress is laid by the corf- 
tributors on so treating the land by autumn cultivation, that when the seed i& 
sown in spring a gr od tilth is steured of the fine soil, broken down by the winter 
frosts, which is kept on the siuface by the use of scarifiers. This operation is 
all that is requisite under the circumstances, as the previous thorough cultiva- 
tion makes a spring ploughing unnecessary. Thus instead of a soil which has 
been exposed and dried in the course of jiloughing, and reduced to requisite 
fineness, there is a t;ood tilth on tlie surface, foiming a first-rate seed bed, free 
from the clods which are a special shelter to '■ fly," while below the surface there 
is a soil in excclbnt state, both as regards cultivation and manuiial condition, 
but still not robbed of the store of moisture which aids materially in pushing oa 
the plant past attack. — E. A. O. 
