THE WALNUT BUD MOTH.
_Acrobasis caryae_ Grote?
Inconspicuous nests containing small caterpillars are often found at the
ends of the new shoots of _Juglans regia_, seriously injuring them, and
sometimes killing the trees. One small tree two feet high was killed,
and thirty-five pupae were found in the nests at Dr. Morris' farm in
1912. The adult is a small gray moth with a wing expanse of about
three-fourths of an inch. There are three broods each season in
Connecticut, the larvae appearing about June 1, July 10 and August 18.
By spraying the foliage with lead arsenate (3 lbs. in 50 gals. water)
this insect can be controlled. One application should be made about June
1, followed by a second about July 10.
Though this insect is thought to be _Acrobasis caryae_ Grote, it is
often difficult to distinguish some of these species in this genus
without a knowledge of their food habits and seasonal life histories. We
possess such knowledge regarding this species which we have studied and
reared in Connecticut, but it is lacking in connection with adult
specimens in the United States National Museum labeled _caryae,_ which
superficially seemed identical with ours. Further study, therefore, may
prove this to be an undescribed species. There are other bud-worms
attacking nut trees, especially in the southern states, where they cause
considerable damage to pecans.
THE WALNUT WEEVIL OR CURCULIO.
_Conotrachelus juglandis_ LeC.
Probably the most serious enemy of _Juglans_, in Connecticut at least,
is the walnut weevil or curculio, _Conotrachelus juglandis_ LeC. The
larvae tunnel in the tender shoots, often ruining the new growth, and
they also infest the nuts. The adults feed upon the shoots and leaf
petioles. Observations on the different hosts indicate that _Juglans
cordiformis_ and _J. sieboldiana_ are preferred, and the most severely
injured, followed in order by _cinerea_, _regia_, _nigra_ and
_mandshurica_.
Though described as early as 1876, little was known about the life
history of this insect until the studies were made at the Station in
1912 by Mr. Kirk and the writer. Formerly it was supposed that this
insect attacked and injured only the nuts or fruit, and Dr. Morris in
1909 seems to be the first on record to observe the injury to the shoots
of _Juglans regia_. It was on the trees of Dr. Morris here in Stamford
and those of Mr. H. L. Champlain at Lyme that the life history studies
were made. There
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