INSECT GALLS 



Rhabdophaga batatas, Walsh. Host Salix humir 

 lis, Marsh. A nodule-like swelling of the stem of the 

 prairie willow. Very variable in size and shape. 



Rhabdophaga strobiloides, Walsh. Host Salix 

 cordata, Muhl. A top-shaped mass of leaves, pro- 

 duced by a shortening of the stem axis of the host, 

 constitutes the principal mass of this gall. 



Eurosta solidaginis, Fitch. Host Solidago cana- 

 densis, L. The gall consists of a spherical swelling 

 of the stem of this golden-rod. When dry it is pith- 

 like in structure throughout. 



Order COLEOPTEKA. 



Podapion gallicolla, Riley. Host Pinus resinosa, 

 Ait. An ellipsoidal to spherical swelling of the 

 branches of red pine. 



Saperda concolor, Lee. Host Populus candicans, 

 Ait. A more or less regularly ellipsoidal swelling 

 of the stem or branches of the host. The producer 

 emerges early in May. 



Order HYMENOPTERA. Family Tenthredinidae. 



Sawfly gall producers infest only the willows. 



Euura Salix gemma, Walsh. Host Salix Jiumilis, 

 Marsh. This gall is produced by the swelling of a 

 lateral bud. 



Euura Salix ovum, Walsh. Host Salix cordata, 

 Muhl. A monothalamous gall consisting of an elon- 

 gated oval swelling on one side of a twig. 

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