INSECT NOTES. 36/ 



noticeable inroads, while spittle insects and plant lice (Lachmns 

 strobi and Chermes pinicorticis) have been unusually prevalent. 

 None of these insects, however, have been the cause of the 

 "white pine blight," * though several of them Chermes pinicor- 

 ticis and the spittle insects, Aphrophora parallela, for instance, 

 have been in some cases conspicuously associated with the ailing 

 trees. 



Eriophyes fraxiniphila Hodgkiss 



and 



Eriophyes fraxini (Karp.) Nal. 



Ash Clusters and Gall Mites. Lot 429. 



In the vicinity of Orono the red ash is commonly covered 

 with distorted growth somewhat of the appearance of "witches' 

 broom." Figure 58. In some cases these clusters hang from 

 every branch and give the tree a strange appearance after the 

 leaves have fallen. Examination of one such cluster taken 

 October 10, 1908, revealed thousands of microscopic mites, some 

 transparent and some pinkish, moving over the irregular sur- 

 face. Similar galls are recorded by Murray as the so-called 

 clusters of ash,t caused by an unnamed mite. 



The mites that cause the physiological disturbance in the plant 

 tissue which results in this erineum or gall are so small as to be 

 almost invisible to the unaided eye. Examination of the gall 

 under a Zeiss binocular gives a very interesting glimpse of these 

 minute creatures on the gall and reveals the characteristic 

 movements of the mites as well as their color and a general idea 

 of their form. An oil emulsion, however, is necessary to give 

 any definite details. 



* A discussion of the "white pine blight" is given by W. J. Morse in a 

 forthcoming bulletin of the Maine Agricultural Experiment Station, and 

 by the same authority under the title "The White Pine Blight in Maine" 

 in the Report of the State Forest Commissioner of Maine, 1908. 



t "They are the monstrous deformed styles of the flower, which gather 

 into a ball, brownish green at the beginning, later on a dark brown, 

 causing rough masses on the upper part, which have on the outside a 

 great similarity to fragments of the upper part of a cauliflower. Its 

 upper side is clothed, as it were, with colourless hair cloth, from which 

 come stick like hairs. They are solid, without any hollow space, and, 

 in a dry state so hard that they can be sawn and cut like wood." Eco- 

 nomic Entomology, Aptera, p. 364. 



