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 pale pea-green caterpillar striped with lemon-yellow often defoliates the plants in the southern states.
The young caterpillar may be killed by spraying with "Black Leaf 40" tobacco extract, one part in 650 parts water, adding soap to make the liquid spread and stick better.
Acer. Box-Elder Bug (Leptocoris trivittatus) is about 1/2 inch in length, dark gray in color marked with red. They congregate about box elder in great numbers, on the sap of which they feed. The young nymphs may be killed by spraying with ordinary contact insecticides.
Cottony Maple Scale (Pulvinaria vitis) is a brown, soft-bodied, scale insect, 1/5 inch in length. The eggs are laid beneath a conspicuous cottony mass which protrudes from under the scale. The eggs hatch during June and July, and the fertilized females hibernate on the smaller branches. There is one generation annually.
A stiff stream of water will dislodge many of the mature scales in June or July. The young scales may be killed with tobacco extract. The most effective treatment on maples is 15 per cent kerosene emulsion applied during the dormant season to kill the hibernating females.
Green-striped Maple Worm (Anisota rubicunda) is a large, pale yellowish green caterpillar, striped with dark green, that occasionally defoliates the maple.
The young caterpillars may be controlled by spraying with arsenate of lead, four to eight pounds to one hundred gallons of water.
Pigeon Tremex (Tremex columba) is a large four-winged fly having a wing expanse of 2 1/2 inches. The abdomen ends in a prominent ovipositor. The larva, over 2 inches long when full-grown, burrows in the wood, seriously injuring the tree when abundant. Vigorous trees usually overcome the attack.
Several species are occasionally injurious.
"Black Leaf 40" tobacco extract, three-fourths of a pint to one hundred gallons of water, adding four pounds of soap, is an efficient remedy.
Sugar-Maple Borer (Plagionotus speciosus) is very destructive to hard maples. The parent beetle is about an inch long, black, brilliantly marked and banded with yellow. The larva is a large borer about 2 inches in length when mature. They burrow mostly in the sapwood, several often girdling and killing a tree. It is a difficult matter to prevent this injury.
Digging out the borers is the only remedy known.
Woolly Maple-Leaf Scale (Phenacoccus acericola) is a soft-bodied woolly-covered insect about 1/4inch long, found on the under side of the leaves. There are two or three generations a year. They hibernate as young on the bark of the trunk and branches.
Winter applications of whale-oil soap, one pound in one gallon of water, have given the best results.