BULLETIN NO. 231
g THE RELATION OF THE KENTUCKY SPECIES OF
  SOLIDAGO TO THE PERIOD OF ACTIVITY -
r `J ` OF ADULT CYLLENE ROBINIAE
V By H. GARMAN I
.9
‘ The close association of some insects with plants upon
. which they feed has been a subject of remark for many years,
a   but as far as I know attention has not before been given to this '
_ i species and its relation to the plants upon which the adult
. beetle feeds and upon which it seems to be dependent. In a bul-
;S   letin on the life-history and ecology of the locust borer pub- ’
. lished in 1916** a particularly close relation was recorded be- i
I tween the adult insect and the tall goldenrod (Solidago allis-
sinzu) growing on open ground in Kentucky, and the present I
St e publication is in the main a continuation of observations on this
3  food plant, together with others made on related species of I
 I the genus and on a few other genera of Compositae. —
  The life period of the adult borer as determined by collec-
  tion and observations made from December ].-I, 1885), up to the
  present time, extends from September 2 to October 31, the length
Y " of the period elapsing after the beetles begin to emerge depend-
·  _ ing on the earliness of killing frosts. When these come, the
' goldenrod iiowers are destroyed and tl1e beetles at once disap-
pear. If frosts come near the first of October the period for
the beetles may be shortened a month. Beetles are always
. found soon after the first of September, when they begin to
‘ appear, and as long thereafter as uninjured goldenrod remains
 . *Unlleli112O