Types of Garden Enemies
BRISTLY ROSE-SLUG (Cladius isomerus).
The larva, yellow green with a dark stripe down the back and stiff hairs, both skeletonizes the leaves and eats holes through them. There may be several generations a season, and slug damage in late summer is probably from this species. It winters in brown papery cocoons in garden trash.

CURLED ROSE SAWFLY (Allantus cinctus).
The greenish larva, with grayish sides and legs, feeds from a coiled position along the leaf edge, consuming all leaf tissue. It enters the pith of rose canes through pruning cuts and pupates there. There are 2 generations.

Control. All rose sawflies can be readily controlled by spraying or dusting foliage with DDT, lead arsenate, or rotenone. To reduce injury from the curled rose sawfly, avoid fall pruning when the wood does not callus quickly and prune out infested canes below the insect as soon as possible. It may be wise to paint large pruning cuts, but I never have time.

Diseases with an overgrowth of tissues in a limited area are commonly called scab.

APPLE SCAB (Ventuna inaequalis).
This is the top-ranking apple disease, ruining the crop in a rainy season unless a carefully timed spray schedule is carried out. The fungus winters in dead leaves on the ground and in wet spells in spring shoots out spores which are carried by wind to buds, blossoms, or young leaves overhead. Dark spots on blossoms are followed by dropping of young fruit. Leaves have sooty areas, slightly domed, and bear olive-brown conidia which are splashed by rain to other foliage and fruits. Fruit spots are small, more or less raised, dark olive; but as the fruit grows they rupture, leaving a white rim around a dark velvety center; still later the dark mycelium and spores disappear and the spot is raised, corky, tan in color. When spots are too numerous, the fruit splits.

Control. Sulfur is rather generally used, often combined with Fermate, starting a week after the delayed dormant spray and continuing weekly through petal fall and then somewhat less often. Scab control is a job for the orchardist and not the backyard grower. There is a warning service which tells farmers when old leaves are ready to shoot their spores so that the first spray can be applied in time. Captan, Phygon, glyoxalidine, and mercury compounds are coming to have a place in scab control.

PECAN SCAB (Cladosporium effusum).
The fungus attacks pecan and hickory rather generally. Leaves turn black and fall; nuts have small circular spots which grow together until the whole nut is black and often drops.

Control. Jar branches to make diseased nuts drop, then clean up. Spray with low-lime bordeaux when leaves are 1/4 to 1/2grown, after pollination, and twice more at 3- to 4-week intervals. Varieties Moore and Money- maker are rather resistant.

Fig. 49

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