346 
The Ohio Naturalist. 
[Vol. V, No. 7, 
LIFE HISTORY NOTES ON APION NIGRUM. 
E. C. COTTOX. 
The genus Apion, family Cnrculionidae, contains several 
serious pests among which are two or three that do considerable 
damage to the clover plant. Two memljers of the genus A. 
nigrum and A. rostrum belong to the fauna of the black locust 
(Kobinia pseudacacia) . Our knowledge of the habits and life 
history of these two species is incomplete. It has long been 
known that the adults of A. nigrum feed upon the black locust, 
eating holes in the leaves and it has been supposed that the lar- 
vae, as the larvae of nearly related species, “develop within the 
seeds of this tree’’ (Insect Life, 5;338). However, the seeds of 
the black locust are but little larger than the adult curculio so 
that this could hardly be true, and some observations made 
during the past summer disprove this supposition. 
While engaged as Assistant Nursery and Orchard Inspector 
the writer visited Marietta on May 22, 1904, and found many 
adults of A. nigrum working upon the unopened flower buds of 
the black locust trees west of that town. On closer observation 
it was noted that the females were puncturing the buds and 
ovipositing in the holes thus made. On a second visit to this 
locality, on May 26, the insects were as numerous as before and 
it was noted that many of the buds had ceased to develop and 
were falling to the ground where they remained fresh for some 
time. Many of the fallen buds had the pedicle still attached, 
but a larger part did not. An examination showed that nearly 
all of the prematurely falling buds had been punctured in one or 
more places, and upon opening them, all stages of the insect were 
found, i. e., eggs, larvae, pupae and adults. Usually only one 
stage of the insect was found in a single bud and normally but 
one develops in a given bud yet there may be two or more. 
From some of these buds the adults had emerged by eating a 
round hole, generally through the base of the bud but some ate 
their way out at about two-thirds of the distance to the tip. 
One raceme upon which twelve adults were observed feeding 
and ovipositing, was found to contain thirty buds, twenty-five 
of which had been punctured in sixty-three separate places. 
The highest number of punctures in any one bud was seven. 
From thirty of these wounds a viscid, gummy substance was 
exuding. About fifty of these buds were collected from the 
ground and placed in a glass jar, on May 26th, and on June 5th, 
twenty adult curculios, one pupa and four larvae were taken 
out, and on June 11th, seven more adults were removed. 
