REPORT OF THE STATE ENTOMOLOGIST I909 81 



showed that there had been considerable colonies several inches 

 below the surface, the infested points being marked by an 

 abundance of woolly, waxy matter and in some instances there 

 was considerable exudation from the roots, possibly as a result 

 of the injuries inflicted by this plant louse. Mr Pettis, writing 

 under date of October lo, states that the plant lice appear to 

 live in the ground at night but with the appearance of the sun 

 they emerge and fly, the phenomena he observed probably being 

 the normal autumnal flight. The trees affected were all native 

 pines and so far as a superficial examination went, appeared to 

 be in excellent condition. 



Gall-making aphids 



There are a number of species of plant lice particularly in- 

 teresting because of the vegetable deformations, more generally 

 termed galls, which they produce. Ordinarily these gall-making 

 species are not very injurious though their effects upon plants 

 are frequently somewhat conspicuous. 



Cockscomb elm gall (Colopha ulmicola Fitch). The 

 gall made by this species, on elm foliage, is very common and is 

 easily recognized by the long, irregular, frequently red tipped 

 cockscomb swellings running parallel with the veins and some- 

 times so abundant as to seriously deform the leaves. Occasion- 

 ally small trees may bear one or more galls upon almost every 

 leaf, while the foliage of individual branches on larger trees may 

 be badly malformed because of these abnormal growths. The 

 young galls appear about the first of May as slightly elevated 

 ridges on the upper side of the leaf. Soon after, on the opposite 

 surface an elongate opening is seen^ and on pulling the walls 

 apart the glossy, olive-brown plant louse is disclosed within the 

 cavity. This is the parent louse. Four or five weeks later or 

 during the month of June the interior of the gall will be found 

 occupied by numerous young grouped around the mother. 

 Within the gall, among its many occupants, are numerous glis- 

 tening globules of a sweet liquid or honeydew excreted by the 

 plant lice. Later the opening into the gall spreads apart and the 

 insects are thus free to escape. The species is said to winter 

 as eggs deposited in sheltered places on the bark. 



Spiny hazel gall (Hamamelistes spinosus Shim.) . 

 This peculiar form, as determined by the recent investigations of 

 Mr Pergande, has an extremely interesting life history, occur- 



