72 REPORT OF No. 19 



Flat Galls on Willow (Pontania hyalina). 



Fleshy galls, occurring in two parallel rows, one on either side of the 

 midrib, sometimes touching, but not originating from the latter and rarely 

 extending to the edge of the leaf. Sometimes as many as twenty to a leaf. 

 In other cases confined to a row on one side of the leaf, or occasionally oc- 

 curring singly. Shape irregular, elongate-ovate, projecting equally in both 

 surfaces of the leaf. Color on upper side more or less brownish red, be- 

 neath white with slight purplish tinge. "Eggs and larva are subject to at- 

 ,tack of mites, thrips, a curculionid (Anthonomus sycophanta) and a lepidop- 

 terous larva which eats out the entire interior of the gall tenthredinid larva 

 and all." (From Marlatt. "Revision of Nematinae.") Occurs on many 

 species of scrub willow {Salix sp.). Very common. 



Pithy Blackberry Gall (Diastrophus nehulosus). 



A large, oblong, polythalamous stem gall, 1 to 3 inches in length, and 

 1 to li inches in thickness. The surface is uneven with deep longitudinal 

 furrows, which divide the gall more or less completely into four or five 

 portions. Occurs on Blackberry (Rubus sp.). 



Lettuce Tumor Gall {Aulax timidus). 



It occurs on the stem of Wild Lettuce. It is an irregular, oval, poly- 

 thalamous, knotty enlargement of the stem varying greatly in size. The 

 interior is soft and pithy. Occurs on Wild Lettuce (Lactuca Canadensis). 

 Not common. 



Oak Button Gall (Ne/uroterus umbilicatus) . 



This gall appears as a small button-like enlargement on the upper and 

 lower surfaces of the leaves of the Oaks. Occurs on Burr Oak (Quercus 

 Tnacrocarpa) . Not common. 



Oak Bullet Gall (Holcaspis globulus). 



It is found on the twigs of many species of Oak. It is a smooth, round, 

 monothalamous gall. The interior is corky, with a small lighter coloured 

 oval cavity in the centre, containing the larva. It grows singly or in clus- 

 ters of two or three. Occurs on Burr Oak (Quercus macrocarpa), and White 

 Oak (Quercus alba). Common. 



Oak Pea Gall (Cynips pisum). 



This is a spherical dithalamous gall, resembling a small pea. The 

 surface is fissured or netted with depressions between which are elevations. It 

 resembles a small pea. Occurs on White Oak (Quercus alba) and Burr Oak 

 (macrocarpa). Not common. 



Barley Jointworm (IsosoTna hordei). 



A small gall forming a woody growth which fills up the cavity of tlie 

 stalk and causes the joints to swell, and the stalk to topple over. The larva 

 remains in the straw over winter, and the adults emerge in the spring. 



Huckleberry Gall (Solenogopheria vacinii). 



Rounded or elongated galls 1-2 cm. in diameter on the stem of the 

 huckleberry. They are green or red in summer, and brown, hard and woody 

 in winter. Occurs on Huckleberry (Gaylussacia resinosa). Common. 



