[Illustration:  Turnip fly, or flea =Haltica (Phyllotreta) nemorum= (with larva and chrysalis)]

Preventive and remedial measures that can easily be carried out in a garden may be impracticable on a farm.  We propose to enumerate them briefly as they occur to us, leaving the ultimate choice of weapons to those who may unfortunately find occasion to use them.

One precaution is to insure a quick germination of the seed and strong growth of the plant in its seed-leaf stage.  The cotyledons are tender and tasty, perhaps sugary from Nature’s process of malting; and while the seed-leaf is assailable the =Haltica= makes the best of the shining hour.  The seed sown should be all of one age, and the newest possible, because of the need for a quick and strong growth.  When a powerful artificial is sown with the seed, the quantity of seed must be increased, as a proportion may be killed by the manure.  It is important always to drill Turnip seed; broadcasting seems to invite the Fly—­at all events, a drilled crop is generally safer.  Before sowing, the seed may be soaked in paraffin or turpentine.  Of the two the latter appears to be the more successful in keeping the insects at bay.

Rolling an infested plant disturbs and weakens the insects and stimulates the young plant.

The sprinkling of slaked lime over the seedlings is at once a safe and an efficient process, and possesses the additional advantage of being beneficial to the plant.  We are aware that it does not always succeed, but we are inclined to attribute the failure to a bad quality of the lime, or a careless method of employing it.  There should be enough put on to make the plants white, and they will be none the worse for the whitening.  Dustings of fine ashes or soot are scarcely less effective, but salt must not be used, for it injures the plants and does not hurt the beetle.  All such dustings should be done in the early morning, while the plants are wet with dew.  To apply a dusting at midday, when the sun shines gaily, is to waste time, and probably many of the recorded failures might be explained if we knew at what hour and in what sort of weather the work was done.  Nets and sticking boards have been tried and found effectual, and yet such things are rarely used.  A board thickly covered with white paint, drawn over the plot on a still, sunny day, soon becomes a black board by the myriads of =Halticas= that jump at and remain attached to it, the victims of their extravagant love of light.  Old sacks soaked in paraffin and drawn over the drills impart a disagreeable flavour to the leaves, and a very fine spray of paraffin distributed by a machine specially constructed for the purpose has proved effective.

Finally, this, in common with all other insects in the winged state, needs a dry air and some degree of warmth for its health and happiness.  Many kinds of larvae need moisture, but no winged insect can abide moisture long, and herein is a clue to the eradication of Turnip Fly.  By the simple process of spraying the plant three or four times a day, until it is out of the seed-leaf, and the danger is over, it is possible in the garden to wash out the =Haltica=; and any kind of insecticide or flavouring, such as quassia, may be mingled with the water to render the plants distasteful to the insects.