'I 
Vol. LXIV. No. 2895. NEW YORK, JULY 22, 1905. WEEKLY, $1.00 PER YEAR 
SOD OR CLEAN CULTURE FOR INSECTS. 
Which Gives Them the Better Chance ? Why ? 
There is some difference of opinion among practical men 
as to whether insects are more damaging in an orchard kept 
in sod than in one thoroughly cultivated. Some growers 
claim that certain insects prefer grass or certain weeds to 
the foliage, and for this reason trees in sod will be cleaner. 
We would like to have the subject discussed. Are there any 
of Our common injurious insects that would be likely to leave 
fruit trees for weeds or grass? Which do you think would 
be the more likely to suffer .from insects, a sod or a culti¬ 
vated orchard, and why? 
Not Much Difference in New Jersey. 
This raises an interesting question, and one that may 
be answered differently in different parts of 
the country. Speaking for New Jersey alone, 
it makes very little difference whether the 
orchard is in sod or cultivated. The two 
serious orchard pests are Codling moth and 
Plum curculio; neither one of them can, un¬ 
der any circumstances, feed on anything ex¬ 
cept the fruit. In a cultivated orchard the 
dropped fruit is more readily seen and picked 
up, and so it is easier to keep the orchard 
clean. On the other hand, the curculio finds 
it easier to get underground, and it has fewer 
enemies that lie in wait for it. Where an 
orchard is in sod there are always a consid¬ 
erable number of predatory forms, and pos¬ 
sibly fewer curculios would escape; assum¬ 
ing that an effort was made to pick up the 
dropped fruit in any case. As for the in¬ 
sects that feed on apple leaves, none of them 
would abandon an apple tree for a sod. If a 
sod is maintained for any considerable length 
of time, it will become filled with cutworms, 
wircworms and white grubs. These do not 
ordinarily attack fruit trees, but in some sea¬ 
sons when May beetles are urusually com¬ 
mon they may cause some injury to foliage 
and even buds in apple and pear orchards. 
On the whole, as between the two, a culti¬ 
vated orchard offers rather less chance for 
injurious insects than one that is in sod. 
On the other hand, the difference is so slight 
that if a farmer considers it to the advantage 
of his orchard to keep it in sod I would not 
advise him to alter his plans in order to give 
clean culture. John b. smith. 
N. J. Experiment Station. 
The New York Bug Man's Opinion. 
It is my belief that, as a general rule, most 
orchard insect pests will not thrive as read¬ 
ily in cultivated as in uncultivated orchards. 
Yet I am fully aware that this is largely the¬ 
ory, as I do not know that anyone has made 
a careful experiment along this line. The 
Plum curculio is a serious pest in apple 
orchards in Missouri and Illinois, and it has recently 
been demonstrated that cultivated orchards suffer much 
less from this insect. It is also a well-known fact that 
cultivated orchards rarely suffer seriously from canker- 
worms. Of course, there are several orchard pests 
which do not go into the ground during any stage of 
their life; fa*iiliar examples are the Codling moth and 
the tent-caterpillar. Such insects, theoretically, should 
be little influenced by cultivation, and I doubt if uncul¬ 
tivated orchards which are well fed suffer any more 
from these two pests. In making this comparison one 
should not include uncultivated orchards which are 
neglected, for in such orchards I believe insect pests 
would find more congenial surroundings and thrive bet¬ 
ter than in well fed or cultivated orchards. But not 
everyone can grow apples successfully by practicing 
the sod-culture method. There are, it is true, a few 
orchards that are so peculiarly located and so well en¬ 
dowed by nature as to thrive under the sod-culture 
system, and I do not think insects find more congenial 
quarters in these orchards than in those which are 
thoroughly cultivated. I know of only one case where 
a certain insect pest of the apple prefers certain grasses 
to the foliage of the trees; this is one of the common 
apple aphids or green lice, which frequently appear in 
iarge numbers on the opening buds in the Spring. One 
of these aphids deserts the apple leaves early in the 
season and migrates to the June grasses, where it breeds 
during the Summer, and then goes back to the apple tree 
late in the Fall, where it deposits its Winter eggs. Thus 
it simply uses the apple tree as hibernating quarters and 
to furnish it food for two or three weeks in early 
Spring. I know of no other orchard insect pest which 
.prefers grasses or weeds to apple foliage, so I do not 
believe this argument is a good one for those who 
think that trees in sod would, therefore, be cleaner from 
insect pests. Briefly told, I should not expect any notice¬ 
able difference in the number or ravages of insect pests 
in two orchards, which were well fed and taken care 
of, and which differed only in that one was growing in 
sod and the other was thoroughly cultivated. 
Cornell University. m. v. slincerland. 
Keep the Orchards Cultivated. 
There is no question that it is better to keep the 
ground under an orchard cultivated. At least, I most 
certainly recommend keeping the ground plowed and 
often stirred. Many bad pests, as the Trypeta, “Rail¬ 
road worm,” etc., take refuge in the ground during a 
part of their lives, and stirring the earth throws some 
of them up where they are eaten by birds or killed by 
atmospheric conditions or frost in cold weather. None 
of the pests of fruit trees that is worth noticing would 
leave the trees to betake itself to weeds or grass. The 
idea is absurd. The grass or sod might well serve as 
a shelter for injurious insects during the Fall and Win¬ 
ter, but it could never lessen their attacks by diverting 
them to their own leaves or stem. A clean, well-culti¬ 
vated orchard is much less liable to suffer from injurious 
insects than one in sod. g. h. perkins. 
Vermont University. 
Clean Fruit Under Cultivation. 
So far as my observations go, cleaner and better fruit 
can be grown in a cultivated orchard than in 
one which is kept in sod, although I have 
seen excellent fruit grown on trees which 
were in a sheep pasture, but here the diseased 
and wormy fruit which dropped to the 
ground was all destroyed by the sheep. Of 
course if hogs are kept in an orchard it is 
practically a cultivated orchard. While it is 
true that certain species of plant lice migrate 
from fruit trees to weeds or grasses, where 
certain generations live, the fact that the 
weeds and grasses grow in the orchard 
would make no difference with the trees, but 
would only make it more convenient for the 
migrating plant lice. They would migrate 
just the same if they were obliged to go to 
an adjoining field, or perhaps to a distant 
one. On the other hand, borers in both apple 
and peach trees have seemed to he more trou¬ 
blesome in uncultivated orchards, or even in 
cultivated ones where there was a mulch left 
round the trunk of the tree. I am also rea¬ 
sonably sure that stirring the soil close up 
to the trunks of the trees through June, July 
and the first half of August would do much 
to help check such insects as the Plum cur¬ 
culio, Codling moth, Pear midge, and possibly 
the Apple maggot, which go into the ground 
to pupate. At the present time I can think 
of no insects which are less troublesome on 
trees in orchards where the sod method is 
employed. w. e. britton. 
Connecticut State Entomologist. 
Insects Worse in Trash; Sod Warmer. 
1 here are many of our worst orchard in¬ 
sects which find shelter in weeds and grasses, 
or any kind of trash that is left in the or¬ 
chard. Among such insects are the Codling 
moth and the Plum curculio. A list of 
others, too long for enumeration, also find 
similar shelter. However, in orchards fol¬ 
lowing clean culture severe Winters often in¬ 
flict so much injury that the vitality of the 
trees is reduced, inviting attacks of some in¬ 
sects that are almost sure to inflict fatal damage. Trees 
injured by cold are especially liable to the attacks of 
Bark beetle, and when they have once commenced there 
is less hope for the tree than if it were attacked by 
San Jose scale. Answering your question as to 
whether any of our common injurious insects are likely 
to leave fruit trees for weeds and grass, there are some 
that occasionally inflict a good deal of damage and pre¬ 
fer weeds and grass. For this very reason weeds and 
grass in the orchard are apt to breed them in excessive 
numbers, so that they are more likely to attack the 
trees than if clean culture were pursued. It is a gen¬ 
eral law of insect life that abundance of food will in¬ 
crease the number of insects to such a degree that they 
are likely to seek food plants which ordinarily are of 
second choice. I believe an intelligent fruit grower 
can keep his orchard in sod or can have clean culture, 
and so adapt his practice to his method that he will 
A GOOD CLUSTER OF PRESIDENT. NATURAL SIZE. Fig. 229. 
See Page 551. 
