02 THE REPORT OF THE No. 19 



ond stage seems to occur in July. In this month the galls elongate on the 

 lower surface into nipples 3-4 mm. long and 1-1.5 mm. in diameter. The 

 color is rather lighter than before, except that the end of the nipple itself 

 is often nearly black. The pubescence is much more visible than before. 

 The galls occur either singly or in closely united groups of 2-15, chiefly 

 along or near the midrib. They are monothalamous but no larvae were 

 discovered in the specimens examined. Willow-leaf Bead and Nipple Gall — 

 (Undescribed) — Salix rostrata. 



B. — Galls on stems. 



Large, rough galls on the stems of the Willow. The galls are smooth 

 at first but become rough later in the season. • Willow Branch Gall — Saperda 

 concolor — Salix sp. 



Cone-shaped mass of closely-imbricated leaves at the end of a twig, 

 caused by the arrest of growth at the end of the stem. Pine Cone Willow 

 Gall — Cecidomyia strobiloides . — Plate 0., fig. 7. Salix. sp. 



Club-shaped gall formed on the lateral shoots of the Willow, an enlarge- 

 ment of the whole stem. About | of an inch in length. Willow Club Gall — 

 CecidoTnyia rigida — Salix sp. 



Oval galls on the sides of the twigs, hard and woody and usually the 

 same colour as the stem. 



Willow Egg Gall, Euura ovum — Salix sp. 



Oblong-ovate, polythalamous galls, about the same color as the bark 

 while young but gray when mature. Willow Potato Gall — Rhabdophaga 

 batatas O.S. — Plate A., fig. 7. Salix sp. 



Irregularly woody, oval enlargement of the stem at the joints or nodes. 

 1-3 to i an inch in length. Willow Joint Gall — Rhabdophaga nodulus 

 (Walsh). Salix sp. 

 C. — Galls of the Buds. 



Altered or transformed buds. The bud scales become elongated and the 

 interior becomes a cavity in which the larva lives. Willow Bud Gall— 

 Rhabdophaga trilicoides (Walsh). Salix sp. 



Affecting Wild Lettuce. 



An irregular, oval, polythalamous, knotty enlargement of the stem 

 varying greatly in size. The interior is soft and pithy. Lettuce Tumor 

 Gall — Aulax tumidus — Lactuca Canadensis. 



Affecting Witch Hazel. 



A conical 'swelling on upper side of leaf. Witch Hazel Cone Gall — 

 Hormaphis hamameliais (Fitch). — Plate I., fig. 2. Hamamelis virginiana. 



Round gall covered with long spines. A deformation of the fruit bud. 

 Spiny Witch-Hazel Gall — Hormaphis sjnnosus — Plate I., fig. 1. Hamam- 

 elis virginiana. 



Affecting Wood Nettle. 



Ball-like galls occurring either on the upper or lower surface of the leaf. 

 Wood Nettle Ball Gall — Cecidomyia umicola — Plate F., fig. 3. Laportea 

 Canadensis. 



A gall consisting of a malformation of the fruit, much like the ball 

 gall on the leaves. Wood Nettle Fruit Gall — Cecidomiyia sp. — Laportea 

 Canadensis. 



Soft, smooth, spongy, oval or rounded gall of a pale brown colour, on 

 the stem. About 1 cm. in diameter. Wood Nettle Pod Gall — (Undescribed). 

 Laportea Canadensis. 



