SD 143
.A5
1917
Copy 1

US DEPARTMENT OF AGRICULTURE,

BUREAU OF ENTOMOLOGY.

L. 0. HOWARD,
Entomologist and Chief of Bureau.

SOME TIMELY SUGGESTIONS FOR THE OWNERS OF
WOODLOTS IN NEW ENGLAND.

BY

F. H. MOSHER, Entomological Assistant,
AND

G. E. CLEMENT, Assistant in Forest Management, Gipsy Moth and
Brown-tail Moth Investigations.

WASHINGTON : GOVERNMENT PRINTING OFFICE : 1917

Issued

, 1917.

UNITED STATES DEPARTMENT OF AGRICULTURE.

BUREAU OF ENTOMOLOGY.
L. O. Howarp, Entomologist and Chief of Bureau.

SOME TIMELY SUGGESTIONS FOR THE OWNERS OF WOODLOTS IN
NEW ENGLAND.

By F. H. Mosner, Entomological Assistant, and G. E. Cement, Assistant in Forest
Management, Gipsy Moth and Brown-tail Moth Investigations.

Farmers and other woodlot owners in New England have, at the
present time, an unusual opportunity not only to realize appreciable
sums from their timber but also to better the condition of their
woodlands and lessen the liability of their being attacked by the
gipsy moth. Because of the increased demand for cordwood it is
now possible to dispose of classes of material not ordinarily mer-
chantable, and while labor is scarce and high priced the increased
cost of getting out cordwood, it is believed, will be offset by the
higher value of the wood. For these reasons timber owners, by
puting into effect a few simple rules regarding the handling of their
timber, will often be able to accomplish all the following objects at
one time:

First. A large amount of low-grade wood can be disposed of to the
advantage of the owner.

Second. A better class of trees with improved growing conditions
will be provided by the removal of inferior trees now standing.

Third. The numbers of gipsy moths may be reduced by the removal
of those trees of which they are particularly fond and upon which
they thrive particularly well.

In cutting cordwood heretofore, the practice generally has been
to cut clean. Where most of the trees on an area are mature, dead,
dying, or defective, a continuation of this practice is to be recom-
mended, but where a large number of young trees are standing it is
often preferable to thin judiciously. Such thinning should be based
on several considerations, among which are:

1, All dead, dying, and defective trees should be cut to make room for live trees,
and in the case of dying trees, to check the development of injurious insects which
may breed in them,

100201°—17 3

4 SUGGESTIONS FOR OWNERS OF WOOD LOTS IN NEW ENGLAND.

2. Species of trees having the highest commercial value should be given every
opportunity to grow and develop well. All other trees interfering with their growth
and development should be removed.

3. Most trees to grow to the best advantage need a large amount of light. A thin-
ning should aim to space the trees so that each individual shall have a proper amount
of light.

4. The foliage of certain species of trees is more desired by gipsy moths than that
of other species. The removal of such trees may often afford relief from these pests.

5. The price of lumber is rising, and the value of woods of good quality will rise
correspondingly. Thinning may often be a great help in the production of such
woods, besides increasing the rate of growth.

6. Cutting clean is injurious to forest soil, and a long time must elapse before another
cut can be grown. Since no one can predict how long war conditions will last, it
seems advisable to cut gradually, removing the poorest trees first and saving the
better ones for higher prices.

There are 75 species of native and naturalized trees growing in

this region. Realizing their varying liability to gipsy-moth attack,
the Bureau of Entomology has conducted extensive laboratory
experiments for a series of years to determine the susceptibility of
each of these species. It has been found that the small caterpillars
will not feed on certain kinds of foliage, although they may seriously
injure the same trees after becoming nearly full grown. Other
trees are eaten freely by caterpillars of all sizes, while some foliage
is never attacked.

All of the laboratory experiments were supplemented by extensive
observations on the feeding of the caterpillars in the field, and from
the data secured the forest trees have been grouped in the following
classes:

Crass I.—Species that are favored food of gipsy-moth larve in all their stages.

Ash, Mountain. Oak, Pin.

Aspen. Oak, Post.

Aspen, Large-tooth, Oak, Red.

Balm of Gilead. Oak, Scarlet.
Basswood. Oak, Scrub.

Beech. Oak, Swamp white.
Birch, Gray. Oak, White.

Birch, Paper.
Birch, River.
Boxelder.

Oak, Black.
Oak, Bur.
Oak, Chestnut.

Crass I1.—Species that are favored food for gipsy-moth larvex after the earlier larva stages.

Chestnut.
Hemlock.
Pine, Pitch,
Pine, Red.

Service Berry.
Sumac, Dwarf.
Sumac, Staghorn,
Tamarack.
Willow, Glaucous.
Witch Hazel.

Pine, White.
Spruce, Black.
Spruce, Red.
Spruce, White,

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SUGGESTIONS FOR OWNERS OF WOOD LOTS IN NEW ENGLAND. 5

Cuass III.—Species that are not particularly favored, but upon which a small propor-
tion of the gipsy-moth larve may develop.

Beech, Blue. Hickory, Bitternut.
Birch, Black. Hickory, Mocker-nut.
Birch, Yellow. Hickory, Pignut.
Cherry, Black. Hickory, Shagbark.
Cherry, Choke. Hop Hornbeam.
Cherry, Wild red. Maple, Red.
Cottonwood. Maple, Silver.

Elm, American. Maple, Sugar.

Elm, Slippery. Poplar, Silver.

Gum, Black. Sassafras.

Crass IV.—Species that are unfavored food for gipsy-moth larve.

Arborvitee. Laurel, Mountain.
Ash, Black. Locust, Black.
Ash, Red. Locust, Honey.
Ash, White. Maple, Mountain.
Balsam Fir. Maple, Striped.
Butternut. Mulberry, Red.
Cedar, Red. Sheepberry.
Cedar, White. Sycamore.
Dogwood, Flowering. Tulip.
Hackberry. Walnut, Black.

Holly, American.

The gipsy moth is such a serious pest over a large portion of New
England that the varying extent to which it feeds on trees of different
species 1s a very important factor in determining what trees shall
be removed and what ones preserved in thinning. Other factors
affecting such determination are the commercial value, rapidity of
growth, and adaptability to different soil conditions of different
species of trees. With these several factors and 75 species of trees
occurring in a multitude of combinations, it can be seen how impos-
sible it is to outline any plan of thinning which will be applicable in
all cases. An attempt is made here, however, to indicate in a general
way some of the qualities of each species which must be considered
in thinning.

TREATMENT OF TREES IN CLASS I.

Beginning with Class I of the foregoing classification, it is found to
be composed of 26 species which are favored as food by gipsy-moth
larve. Ten of these species, namely, mountain ash, gray birch, river
birch, boxelder, scrub oak, service berry, dwarf sumac, staghorn sumae,
glaucous willow, and witch hazel are of little commercial value and
should be removed.

Ten of the species in this class are oaks, including the scrub oak
just mentioned. Oaks growing on light soils and rocky ridges are
usually not very vigorous, grow slowly, and suffer severely from
gipsy-moth attack.

6 SUGGESTIONS FOR OWNERS OF WOOD LOTS IN NEW ENGLAND.

The bur oak, chestnut oak, pin oak, post oak, and swamp white oak
are generally more or less rare and of restricted local occurrence in
this region, so that they have no great commercial importance.
Owing to their great susceptibility to moth attack these trees should
be cut in every case where they are interfering with the growth of
better trees, or where there is an opportunity to replace them with
trees not so liable to moth attack.

The white oak reaches the northern limit of its range in the gipsy-
moth infested region, yet it is one of the most abundant of the oaks.
Its foliage seems to be particularly desired by the gipsy moth, and it
grows very slowly. For these reasons it is not a desirable type for
growth in this region.

The red, black, and scarlet oaks grow well and produce a valuable
class of material. Where young, vigorous trees of these species occur
on good soil in mixture with other trees, they may be left, despite
their liability to gipsy-moth attack, providing that they are not
interfering with the growth of more valuable trees.

Aspen, large-tooth aspen, and balm of Gilead can not tolerate shade,
and they grow well only where they have free access to plenty of
light. Scattered specimens in mixed woods may well be cut, but
pure stands, which occur occasionally, may be left to mature when
they are in demand for pulp or excelsior.

Basswood occurs very much scattered in this region and grows to
advantage only on the best of sites. It may well be eliminated from
all others.

Beech is more abundant in the northern than in the southern
portion of the region. It grows slowly and is tikely to become defec-
tive before maturity. It is perhaps the least liable to damage by the
gipsy moth of any of the Class I trees. It is an excellent fuel and
should be cut heavily when in the way of faster growing and more
valuable trees.

Paper birch demands a large amount of light to grow well and is not
abundant in mixed stands. When it occurs in abundance, it is in
good demand for spool and novelty wood. It makes an excellent
fuel, and scattered specimens could often be cut to the advantage of
trees to be left.

Tamarack is nowhere abundant in the infested region. When dry,
it makes excellent kindling and a hot fire for a short time.

TREATMENT OF TREES IN CLASS II.

Class II is composed of eight species of trees on which gipsy-moth
caterpillars in their earliest stages do not feed, but upon which they
do feed in their later stages. Hence, if stands composed of these
species have in their vicinity no plants upon which the young cater-

SUGGESTIONS FOR OWNERS OF WOOD LOTS IN NEW ENGLAND. q

pillars can feed, the stands may safely be considered immune from
attack. Trees of this class may be grown safely in mixture with trees
of Class IV.

Stands composed largely of one or more of the species of this class
can be made immune from gipsy moth attack by removing the trees
which may provide the young larve with food. There are many
places where a considerable amount of cordwood could be cut most
advantageously with this object in view.

Great care should be taken to protect and preserve young white —
pine and red pine, especially when they occur on poor soils. They
often grow well on such soils, and if they are present the associated
hardwoods which do not grow well on such sites, and which may be
subject to caterpillar attack, may be cut beneficially. Red pine is
not affected by the white-pine blister rust, which is spreading very
slowly among the white pines. If young white pines are given a fair
chance to grow, they will probably reach maturity before being
seriously affected by the rust. ,

Chestnut grows well and yields a valuable product, but unfortu-
nately is subject to attacks of the chestnut blight. It makes a poor
grade of fuel, but with a shortage of the better grades an opportunity
doubtless will be afforded for the disposal of a considerable amount
of this species.

TREATMENT OF TREES IN CLASS III.

Class III is composed of 20 species which are not particularly
favored by gipsy moths, but upon which a small proportion of the
larve may develop. Stands composed of any trees of this class
alone or mixed with trees of Class IV, but containing no trees of
Class I, would maintain only slight infestations and rarely, if ever,
would be defoliated.

Blue beech, choke cherry, wild red cherry, hop hornbeam, and sassafras
have no particular commercial value ordinarily and could well be con-
verted into cordwood at this time.

Black cherry has considerable commercial value, but its occurrence
is generally rare. American elm and slippery elm are also generally
scattered. Unless growing in very good soil, these trees could well be
cut. Cottonwood, bitternut hickory, black gum, silver maple, and silver
poplar are rare. Bitternut hickory makes very good fuel, but silver
maple is not so good. The cutting or preservation of these species
will have little effect in any respect.

The remaining trees of this class, namely, black and yellow birches,
mockernut, pignut, and shagbark hickories, and red and sugar maples
can be grown in comparative safety as far as the gipsy moth is con-
cerned. The yellow birch, hickories, and sugar maple make the best

5 csnnone wx anne woe oe UOT,

of fuel, but they also produce excellent grades of lumber. With tuet
of this class in great demand, there will be a temptation to cut young
trees of this species. Dead, dying, and defective trees may well be
removed now, but young and vigorous trees should be left to grow to
larger and hence more valuable sizes.

TREATMENT OF TREES IN CLASS IV,

Class IV is composed of 21 species of trees on which the gipsy moth
does not feed, or if it does, the amount is so slight as to be entirely
negligible. Stands composed of trees of this group alone or combined
with trees of Class II need cause no anxiety whatever as far as gipsy-
moth attack is concerned. Flowering dogwood, mountain laurel,
mountain maple, striped maple, and sheepberry have little or no com-
mercial value locally, and if large enough could well be cut for cord-
wood at this time.

Arborvite, black ash, and white cedar occur usually in or near
swamps. They need no consideration as fuel.

Butternut, red cedar, locust, honey locust, and sycamore all require a
large amount of light, for which reason they occur rarely in mixed
woods, and they are of little importance as fuel.

Red ash, hackberry, American holly, red mulberry, tulip, and black
walnut are so rare as to require little consideration.

In this region of degenerate woods, cuttings or thinnings among
young trees should almost always be made with a view to improving
the quality of the trees left, or the future growth. This means that
woodland should be kept fully stocked, but not crowded, with
vigorous trees of the most valuable species. If inferior trees are cut
out, care should be taken to protect seedlings and saplings of better
species which may be on the ground, for otherwise, in the case of
deciduous trees, sprouts will grow vigorously, and the same old con-
ditions will reappear. When young growth of desirable species is not
present, and no provision can be made for introducing better trees, it
may often be better to leave the existing stand than to cut it.

It is realized that the foregoing suggestions can serve only in a very
general way as a guide for thinning, but it is the desire of the Bureau
of Entomology of the United States Department of Agriculture to aid
the woodland owners of this region in every possible way, and the
writers would be pleased as far as possible to confer with any owner
in this region who is seriously interested and will apply to them in
person or by letter at Bureau of Entomology office, 964 Main Street,
Melrose Highlands, Mass.

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