This section is from the book "The Standard Cyclopedia Of Horticulture Vol2", by L. H. Bailey. See also: Western Garden Book: More than 8,000 Plants - The Right Plants for Your Climate - Tips from Western Garden Experts.
A large soft-bodied scale, 1/2 inch in length, hemispherical in shape with a frost-like covering of wax.
Kerosene or distillate emulsion while the trees are dormant.
Columbine Borer (Papaipema purpurifascia) - The full-grown caterpillar measures 1 3/8 inches in length, salmon-pink in color with three narrow stripes visible from above, the two lateral ones broadly interrupted in the middle. It bores in the stems near the base.
Treatment - Dig out and destroy caterpillars.
Stem Maggot (Straussia longipennis) - A small yellowish maggot boring in the pith of the stems. The adult are two-winged yellowish flies with banded wings.
Encourage growth; vigorous plants outlive injury.
Beetle, less than 1/4 inch in length, yellow, red, and shining black, with conspicuous ornamentation, feeding upon the tender shoots. Larva feeds upon the leaves and tender bark.
Freshly slaked lime dusted on before the dew has disappeared in the morning. Poultry. Cut down all plants in early spring to force the beetles to deposit their eggs upon the new shoots, which are then cut every few days before the eggs hatch; or leave a row or so around the field as a lure for the beetles where they may be killed with arsenicals. Twelve-spotted Asparagus-Beetle (Crioceris l2-punctata). - Similar to the last, but with twelve spots on the wing-covers.
Similar to that used above, except that the grubs cannot be destroyed by lime, since they live within the berry. Asparagus Miner (Agromyza simplex). - A maggot mining under the skin near the base of the plant.
Leave a few volunteer plants as a trap in which the fly will deposit her eggs. Pull and burn these plants in late June and early July. The flies may be killed before ovipositing with sweetened arsenate of lead.
Large, black, grayish or striped beetles that feed on the flowers. The larvae in general feed on grasshopper eggs.
An active bronzy brown sucking bug 1/5 inch long, mottled with various shades of yellowish, that stunts the terminal buds by its feeding punctures and also injures the flower-buds so that they either do not open or produce imperfect flowers. Injured plants are dwarfed and stunted.
No satisfactory control measures are known. Plants grown in shade are less liable to injury.