Control. Use a copper spray, starting when new leaves appear and repeating 2 or 3 times at 2-week intervals. Or just remove the most disfigured leaves and forget about it; the disease does not seriously reduce
VIRGINIA CREEPER LEAF SPOT (Guignardia bidwellii f. parthenocisst).
Leaves of Boston ivy and Virginia creeper are often covered with
angular, reddish to brown spots, dark brown at the margin, with very
minute black dots in the center. There may be rather serious defoliation.
Control. Properly timed bordeaux sprays, starting as the new foliage
appears and repeating 2 or 3 times, are fairly effective, but the spray
residue is nearly as disfiguring as the disease. Fermate is less conspicuous
and should be satisfactory.
Maggots are the footless larvae of flies, and some have been discussedi
under that heading.
APPLE MAGGOT (Rhagolethts pomonella)
also called railroad worm. This;
is a native insect, found east of the Dakotas, which causes brown
tunnels inside apples, with the flesh breaking down into an ugly brown
mass in early varieties or into corky streaks in late varieties. The flies,
slightly smaller than houseflies, with black bands on the abdomen, emerge
from puparia in the soil from late spring to July, feed for about 2 weeks,
then lay eggs in fruit. White maggots develop slowly, reaching full size
after the apples have dropped. They then leave the fruit and enter the
soil to pupate, there being but one generation in most sections.
Control. The regular spray schedule for codling moth does not take care
of this summer maggot. An additional lead arsenate spray (3 pounds per
100 gallons) is required in late June or early July. DDT is sometimes used.
Picking up and destroying early dropped apples is always helpful.
CABBAGE MAGGOT (Hylemya brassicae).
If cabbage and broccoli seedlings
wilt and turn yellow soon after transplanting, see if there are not
a lot of small, white, legless maggots riddling roots and underground
portions of the stem with brown tunnels (Figure 35). In some soils maggots kill 80% of crucifer seedlings; early turnips and late spring radishes
are frequently injured. Gray flies, emerging from the soil about the time
early cabbage is set out, lay white eggs at the base of the stem or in
cracks in the ground nearby. Hatching in 3 to 7 days young larvae
quickly find the roots, with up to 100 feeding on a single plant. The
underground parts soon rot. There are 2 or more generations.