166 



occur in thi- .'///</ an.. ra. In Colopha the hind 



win. coidal vein: in Si/ii^onciirii they have t\\ 



Tlu- b Llm Gall. Lvlopha ulmlcolti. Among ; the gall- 



mal tbably the most familiar one. 



! is an excrescence or follicle like :nb, which r: 



abruptly from the upper surface of the i ehn ; it is usually 



about an inch long and a r of an inch high ; it is compre>sed. 



anil has its sides wrinkled perpendicularly and its summit irregularly 



ied and toothed ; it is of a paler gn r than the leaf and 



more r less red on the side exposed to the sun; it opens on the 

 under side of the leaf by a long slit-like orifice ; inside, it is wrinkled 

 perpendicularly into deep plaits. The complete life-history of this 



is not known. According to Riley and Monell th< 

 winter egg, which is usually inclosed in the dry skin of a >exual 

 female. This can be found during winter in the crevicesof the bai-k 



the White Kim. The stem-mother which hatches from this 

 forms the gall. She gives birth to numerous offspring: th 



me winged, and constitute the only generation produced within 

 the gall. These winged, agamic females issue from the slit-like 



ling of the gall ; and each gives birth in the course of a day or 

 so to upwards of a dozen young. These are born as pseiulova. 

 They have well developed mouth-parts; and it is probable that 

 when fully grown they give birth to the sexual generation. 



To the genus Schizoneura belong several of our most conspicuous 

 ' Woully Aphids." Among them are the following: 



The Alder Blight, Schiconcura tcssclldta. This woolly loi: 

 often found crowded together on the under side of the branches of 

 alder (Alnus rubra i. and concealed beneath a covering of downy 

 cretion. It also excretes abundantly honey-dew. The result is 

 that the branches infested by this insect, and those beneath the 

 cluster of Aphids, become blackened with fungi that grow upon 

 \\. Tlv Curious fungus which grows in large 



spongy masses immediately beneath the cluster of plant-lice; this is 

 known to botanist- --ins spongiosuin. It is evidently fed by 



the honey-dew that falls upon i*t. 



The Beech-tree Blight. Schi. Concur a imbricator. This infests both 

 the twigs and leaves of beech. Like the preceding species it oc- 

 curs in clusters of individuals, each of which is clothed with a o>n- 



uous downy tion, These clusters often attract attention 



by the curious habit which the insects have of waving their bodies up 

 and down, the plume-like masses of excretion rendering them very 



