MAR 1- 1906 
The Ohio £? Naturalist , 
PUBLISHED BY 
The Biological Club of the Ohio State University. 
Volume III, MAY, 1903. No. 7. 
TABLE OF CONTENTS 
Cook— G alls and Insects Producing Them 419 
Derby— Meeting of the Wheaton Club 437 
Griggs — M eeting of the Biological Club 438 
Lanijacre— N otice to Subscribers 438 
GALLS AND INSECTS PRODUCING THEM. 
Melville Thurston Cook. 
Part III. Lateral Bud Galls. 
In Part II of this series of papers I gave a discussion of apical 
bud galls. The lateral bud galls differ from the apical only in 
point of location ; therefore, this (Part III) may be considered a 
continuation of Part II. There is, however, considerable differ- 
ence in the galls dependent upon the order and genus to which 
the insect belongs and to the part of the plant which is attacked 
by the enemy. These differences may be summed up briefly as 
follows : 
( r) Affection of the tip of the stem causing it to remain in its 
incipient condition and the leaves to remain aborted, instead of 
lengthening. This is well illustrated by the apical bud galls of 
Cecidomyia solidaginis Lw. on Solidago ; Cecidomyia salicis strobi- 
loidcs O. S. on Salix ; and Callirhytis clavula Fitch on Quercus 
alba. (Part II, Phgs. 31, 32, 33.) In these cases we have two 
orders of insects represented but producing similar galls : this, as 
previously explained, is no doubt due to the fact that the insects 
affect corresponding parts of the host plant. 
(2) Affection of the tip of the bud causing it to remain short 
but to become large and globular. This is well illustrated by 
Ho/caspis globulus Fitch (Fig. 34, a, b, c.) By collecting speci- 
mens of this gall in April or early part of May it is easj^ to 
demonstrate that the gall is in reality an enlargement of the stem 
part of the bud. The insect evidently deposits the egg in the 
apical part of the incipient stem. This causes the stem to enlarge, 
forming a globular body, but to remain so short as to form a 
sessile gall on the main stem. The bud scales are at first very 
prominent but gradually shrivel up and are lost, leaving a naked, 
LIBRARY 
NEW YOR1 
AOTANICAL 
GARDEN. 
