Florida Agricultural Experiment Station


during the heat of the day and show a bluish, sickly color. The
plants finally turn yellow and wilt down completely. If these
plants are pulled up it is found that the roots have been eaten
off, and perhaps the main stem mined, by the maggots which
are about /4 of an inch long when fully grown.
 The adult (fig. 75, c) is a two-winged fly, similar in Ap-
pearance to the house- or typhoid-fly but much smaller and with
a proportionally longer abdomen. The female lays her eggs on
the stem of the plant or on the ground near by.
 Remedies.-Repellants placed about the roots of the plants
when first set out are of some benefit in discouraging the females
 from laying their eggs
 Son the plants. Perhaps
 tobacco dust is about as
 practicable as any. Car-
 bolic acid emulsion may
 be used. Liberal fertili-
 zation will enable the
 \ j Jplants to outgrow the
 Jc damage done by a few
 e maggots. Repeated shal-
 l ow cultivation will de-
 stroy many of the eggs
 Sa laid on the ground about
 the bases of the plants.
 FIG. 75.-Cabbage root-maggot (Phorbia The grower should de-
 brassicae): a, Larva; b, pupa; c, female gr
 fly. About four times natural size. (From stroy all heavily-infested
 U. S. Bur. of Ent.)
 plants and should avoid
planting cabbage on land that has just borne a crop of
infested cruciferous plants whether cabbage, cauliflower, col-
lards, rape, mustard, or turnips. The maggot will breed in
wild plants of this family and all such found near the field
should be destroyed.
 Cabbages in an infested seed bed can be treated with car-
bon bisulphide. To do this, make holes with a stick three or
four inches from the infested plant and slanting obliquely under
it. Pour in about a teaspoonful of the carbon bisulphide and
quickly tramp the soil solid to confine the fumes.
 In the Northern States it has been found profitable after
setting the plants in the field to protect them from the attacks
of this insect by using tarred paper discs. These are cut open
along one radius and fitted closely about the plant. It is doubt-