INSECT GALLS 
Amphibolips confluens, Harris, host Quercus 
velutina, Lam. Amphibolips inanis, O.S., host Que 
cus rubra, L. These species are the common large 
“oak apples.” While very much alike in external 
form, the parenchyma zone in the former consists of 
a dense mass of interlocking fibres, while only a com- 
paratively small number of delicate straight strands 
constitutes it in the latter. 
Andricus singularis, Bassett. Host Quercus ru- 
bra, L. In size and external form this gall closely 
resembles Dryophanta palustris, O.S., but its larval 
chamber is suppcrted at the centre of the gall by 
radiating bands of tissue. 
Andricus piger, Bassett, host Quercus velutina, 
Lam. Andricus petiolicola, Bassett, host, Quercus 
alba, L. ‘These galls are both produced by the swell- 
ing of the midrib or petiole, but can be distinguished 
by means of the different hosts. 
Aulacidea nabali, Brodie. Hosts Prenanthes 
alba, L., and Prenanthes altissima, L. A large 
spherical swelling of the base of the stem of two of 
our rattlesnake-roots, usually just below the ground. 
Aulacidea tumida, Bassett. Host Lactuca cana- 
densis, L. This species produces an elongated swell- 
ing of the stem of the wild lettuce, situated near its 
summit, usually in the panicle. 
Biorhiza forticornis, Walsh. Host Quercus alba, 
L. The individual gall is almost spherical in shape 
and has suspended at its centre by radiating fibres 
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