Types of Garden Enemies
Use lindane emulsion according to directions on the bottle or wettable powder at the rate of 1 pound of 25% wettable to 100 gallons of water. Or use chlordane at rate of 5 pounds 40% to 100 gallons. Summer sprays with dieldrin and aldrin will kill miners inside the leaves.

BOXWOOD LEAF MINER (Monarthropalpus buxi).
This fly is our most serious boxwood pest. Infested bushes often have every leaf blistered (Figure 32A) and look decidedly unthrifty, dying little by little. Inside each blotch or blister one to several small yellow to orange wriggling maggots live through the winter. Near the first of May (in New Jersey) they quiet down, acquire dark heads, and little opaque windows are formed over the blisters on underside of the leaves. Pupa cases are then pushed through these windows, and small orange flies emerge to lay eggs. Emergence varies according to the season and location. The earliest date I have recorded in my practice is May 8th, the latest May 20th; the average is May 14th. Further south emergence would be a week or two earlier. The flies are present for only 10 to 14 days, and there is only one generation.

Control. We used to rely on a sticky molasses and nicotine concoction, putting it on again after every rain and never getting much result. DDT now gives really spectacular control. One application, properly timed, of 2 tablespoons 50% wettable DDT per gallon, is effective, but it must be in place before the flies come out. They start egg-laying the same day. If cool weather delays emergence a week or more after expected, a second application of DDT may be desirable. Early summer spraying with lindane will kill young larvae in new leaves.

COLUMBINE LEAF MINER (Phytomyza minusculd).
Serpentine mines, striking white winding tunnels, are seen in nearly every clump of columbine. Dark flies emerge from the soil in May and June and lay eggs on underside of leaves. Pale maggots feed for about 2 weeks, then form brown puparia on the leaves, with adults appearing in another fortnight. There are several generations a season with pupation of the last brood in the soil.

Control. Spading the ground around the clumps in spring destroys many overwintering pupae. Spray or dust foliage with DDT.

HOLLY LEAF MINER (Phytomyza ilicis)
a European insect common on American holly, sometimes on other kinds of Ilex. The pale-yellow maggot, 1/8 inch long, makes a yellow-green blotch mine visible on the upper leaf surface. It stays in the mine over winter, emerging as a small black fly in late May or when there are 2 or 3 new leaves on the terminal twigs




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