162 EXPERIMENT STATION RECORD. 



species to which the name S. amer'icana has been commonly applied, and which 

 curls or rolls elm leaves, is the one considered in the present bulletin, " Since 

 the name lanigera takes care of the rosette species on elm as well as on apple, S. 

 americana seems to be left free for the aphid curling or rolling the leaf of the 

 American elm. Riley's description of the leaf deformations caused by S. 

 americana seems to indicate clearly enough that he originally applied this name 

 to both these species as his successors have certainly done until recently ; and 

 the synonymy 'Schizoneura lanigera (americana in part, of authors)' correctly 

 designates the ' rosette aphid ' of the elm." 



The present paper outlines the chief points in the life cycle of the second or 

 " rolling aphid." The author finds that when spring migrants leave the elm leaf 

 which has furnished sap for their development they are led to Juneberry 

 (Amelanchier) which is common in ^Maine. When the migrant reaches one of 

 these bushes it settles upon a leaf and soon afterwards creeps to the underside 

 where it remains quietly, ordinarily for the rest of its life. Before many hours it 

 begins to give birth to young and continues this process for several days. These 

 young soon walk down the stem of the plant and later arrive on the under- 

 ground stems of the Juneberry where they settle in groups. This becomes the 

 summer residence of the species. In the fall a generation of winged female.s 

 is developed among the underground forms and these, the fall migrants, leave 

 the Juneberry and take flight to the American elm. 



Among the several predaceous insects which frequent the elm leaf curls of 

 this aphidid mention is made of a capsid (Camptobrorhis nitcnJ^), a coccinellid 

 larva, and syrphus maggots. In regard to control measures the author states 

 that where the Juneljerry is planted for park or ornamental purposes within 

 aphidid flight of American elm, it would seem desirable to try drenching the soil 

 at the base of the shrub with blackleaf 40 or other good tobaccor decoction. 

 Phobably once about mid-July and again late in the month would be the most 

 favorable time for this treatment as the colonies would be young and susceptible 

 and likely to be nearer the surface than later in the season. Young elms can 

 be protected by spring sprays of tobacco decoction before the leaves become 

 curled, "Where largo power sprayers are available old elms sprayed with drive 

 nozzles could probably be cleaned of most of the infestation. Dormant sprays 

 of lime-sulphur heavily coating the elm bark should be tested as to their efti- 

 ciency in killing the overwintering egg. 



The San Jose scale (Aspidiotus pemiciosus), P. A. Glenn (Illinois Sta. 

 Circ. ISO (1915), pp. 5-24, pis. 4, figs. 2). — This is a general account of the 

 origin and distribution, life history and appearance, food plants, and means of 

 distribution and of control. 



Mealy bugs of citrus trees, C. P, Clausen (California Sta. Bui. 258 (1915), 

 pp. 19-^8, figs. S). — Accounts are here given of four of the important mealy bugs 

 which feed upon citrus trees in Southern California, namel.v, Pscudococcus citri, 

 P. baker i, P. citrophilus, and P. loni/ispinus. The injury inflicted has resulted 

 in a considerable loss of fruit and in an extensive dropping of foliage. By far 

 the greatest amount of injury is caused by the common mealy bug (P. citri). 

 An infestation at Uplands. Cal., was found to be caused by a si^ecies now desig- 

 nated as the citrophilus mealy bug (P. citrophilus). 



"The life history during the summer covers approximately two months, the 

 egg stage requiring 8 to 10 days and the nymphal stages a total of about 50 

 clays. Maximum numbers are oi'dinarily found uixm the trees during the early 

 spring and late fall months. The spread from one grove to another is effected 

 upon picking boxes, pickers' clothing, cultivating tools, by birds, etc. Parasites 

 at the present time are not very effective in mealy bug control, and their work 



