The tarnished plant bug is so small that it would hardly seem able to do much damage, but it is the most serious China-aster pest during the hot, dry weather. It punctures the growing tips of the plants so the growth is deformed and dwarfed. A tobacco spray and the dusting of the plants with airslaked lime or tobacco dust is often moderately effective in keeping the bugs in check, but as they are rapid fliers they are seldom killed or completely controlled. The bugs do not work in the shade so that sometimes the plants are not troubled when grown in the greenhouse, under trees or when protected with cheesecloth screens. Cutworms cut off the plant at the surface of the soil.
Grasshoppers eat the flowers and foliage.
Spraying with arsenate of lead will help to control them, as will also poison bait. Blister beetles, black beetles. They appear about the time of the mid-season flowers. In limited quantities they can be jarred into a can of kerosene. They drop as soon as touched or disturbed.