Types of Garden Enemies
ELM SAWFLY (Cimbex amencana).
Larvae are pale yellow green with a black stripe down the back, black spiracles, 8 pairs of prolegs, 13/4 inches long. They rest in a coiled position. Eggs are laid in leaf tissues in May, and larvae feed until late July or August.

EUROPEAN SPRUCE SAWFLY (Diprion hercyniae).
An enemy of north- eastern spruce forests, this species has reached its peak of abundance and is now declining from natural causes. Larvae are light green with narrow white stripes.

IMPORTED CURRANT WORM (Nematus ribesit),
present every season on currant and gooseberry. Greenish worms with numerous black spots feed in from leaf margins (Figure 48A) and when numerous entirely strip the foliage. They winter in cocoons in the ground, and black and yellow adults lay eggs in veins in spring just before leaves are full size. There is a second, less important, generation in late June or July.

Control. Rotenone dust is easy to apply and safe when currants are ripening.

LARCH SAWFLY (Pristiphora erichsonii).
This species appears in epidemics in the Adirondacks and the Lake States, defoliating trees in forests and home plantings. The larvae are olive green with black head, legs, and rows of tubercles, and brownish spines.

PEAR-SLUG (Caliroa cerasi).
On pear, cherry, and plum. Small, dark green to orange, slimy, sluglike larvae, up to 1/2 inch long, skeletonize foliage. First brood larvae, hatching from eggs laid on the leaves soon after trees come into foliage, feed for 2 or 3 weeks then pupate in the soil. The second brood, working in August, may defoliate young trees.

Control. Pear-slugs are readily killed with lead arsenate, at rate of 2 pounds to 100 gallons, plus 4 ounces of soybean flour.

PIN-OAK SAWFLY (Caliroa lineata).
This can appear in decidedly epidemic proportions as we learned to our sorrow in 1948 in New Jersey. All the pin oaks turned brown in the upper third or half of the tree from leaf skeletonization. The larvae look much like pear-slugs.

Control. Either lead arsenate or DDT will control the insect in years when it promises to be important. This enemy provides another good argument for diversified planting. We should not have Oak Lanes lined with the same type of tree ready to succumb all at the same time to a single pest.

PINE SAWFLIES.
Several species infest nearly all ornamental pines at some time during the season.

EUROPEAN PINE SAWFLY (Neodiprion sertijer).
Until control measures were worked out, this rather recently introduced species played havoc with pines in New Jersey watersheds as well as ornamental plantings. It is common on mugho and Scotch pine, rare on white pine. Eggs are laid in slits in the needles and just before hatching, mid-April, resemble pine needle scales




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