476 



MuNEO (W.). Control of the Gipsy Moth by Forest Management, 

 Part II : Management of Typical Woodlots Infested with the Gipsy 

 Moth in the White-pine Region. — U.S. Dejpt. Agric, Washington, 

 B.C., Bull. no. 484, 9th April 1917, pp. 17-49. [Received 7tli 

 August 1917.] 



The conclusions reached in this paper are the results of food-plant 

 experiments co-ordinated with known principles of forest management 

 and with economic conditions in the infested region. Each woodlot or 

 combination of species is found to present its own problem, in which, 

 the controlling factors are site, soil, location, market, value and 

 proportion of the species present, degree of infestation and cost of; 

 labour. While many experiments are still in progress, it is evident 

 that the possible field of forest management as a method of controlling 

 gipsy moth is strictly limited, and even in the case of mixed hardwoods, 

 where some measure of success may reasonably be expected, the cost 

 is often prohibitive. In other forest types, control by forest manage- 

 ment may or may not be an economic possibility. In many stands 

 of the mixed-hardwood type in the white-pine region, spraying and 

 creosoting must be done, while birds, parasites and insects must be 

 relied upon to do their part in control. In cases of severe infestation,, 

 forest management may be less expensive than spraying and creosoting, 

 and has the advantage of being constructive instead of merely 

 palliative, but it cannot be recommended as a general method of 

 control for indiscriminate application by States, cities, towns and 

 private owners of woodlands throughout the infested region. 



Patch (E. M.). Elm Leaf Rosette and Woolly Aphid of the Apple, 

 Schizoneura lanigera [americana in part.) — Maine Agric. Expt. 

 Sta, Ormo, Bull. no. 256, November 1916, pp. 329-344, 10 figs. 

 [Received 7th August 1917.] 



This bulletin is a revised edition of an earlier one [see this Review, 

 Ser. A, i, p. 24]. Eriosoma {Schizoneura) lanigerum is one of the 

 migratory Aphids and passes part of its life-cycle on apple trees and 

 part on the elm. On the apple it occurs as a bark-feeder and is found 

 upon branches, roots and tender places on the trunk, covered with 

 the characteristic white, woolly mass. In August, winged females 

 begin to appear among the wingless ones ; these are the autumn 

 migrants, which fly to the elm and there give rise to the generation of 

 true sexes, the female of which deposits a single egg in a crevice of 

 the elm bark. The stem-mother, hatching from this egg, appears 

 about the middle of May on the partly opened leaf -buds. By the end 

 of May, the stem-mothers are mature and producing the next 

 generation. These nymphs, which are wingless, become fully developed 

 about 10th June. Their progeny are winged and are the spring 

 migrants. For about three weeks from 20th June, migration to apple, 

 mountain ash and hawthorn is taking place. There are apparently 

 three summer generations of progeny of the elm-leaf migrants upon 

 the apple in Maine, two apterous generations being followed by a 

 generation part of which, the autumn migrants, become Avinged and 

 fly to the elm, while part develop into apterous forms remaining on 

 the apple and give birth to nymphs which hibernate at the base of 



