NOTES AND ABSTRACTS. 



647 



(3) Neither parasite survives. 



(e) This may be brought about through premature death of host 

 through excessive parasitism (commonly) ; or 



(f) Through mabihty of either parasite to complete its trans- 

 formations on the limited supply of food. Common. 



The prevalence of superparasitism depends on whether the female 

 parasite is gifted with a prescience which will enable her to select 

 healthy hosts for her offspring. 



The author considers the question of great economic importance in 

 dealing with parasitism as a means of controlling insect pests. — F. J. C. 



Tobacco Culture in Wisconsin. By J. Johnson {U.S.A. Agr. 

 Exp. St7i., Wisconsin, Bull. 206, April 1911; plates). — This bulletin 

 gives the history and statistics of the industry in the State of Wis- 

 consin, points out in which parts of the State the soil is most suitable 

 to the crop, srives full instructions for nreparing the beds for raising 

 the seedlings, and for the subsequen't cultivation of the crop, and a 

 full account of the processes of harvesting and curing. It ends with a 

 list of the varieties which are most- suitable to the climate, and other 

 conditions in Wisconsin. — M. L. B . 



Tree pests, Some destructive shade. By F. L. Washburn 

 [U.S.A. Exp. Stn., Minnesota, nth Ann. Kept. 1909; pp. 165-195; 

 figs.). — A number of insects injurious to ornamental trees are described 

 and figured, and appropriate methods of control are detailed. The insects 

 alluded to are the oak pruner {Elaphidion villosum., Fabr.); two ash 

 borers {Podesesia (Aegeria) fraxini, Lugger, and Papaipenna furcata); 

 the locust borer (Cyllene robiniae, Forst.); the box, elder maple borer 

 [Proteoteras aesculanum, Eiley); the bronze birch borer [Agrilus 

 anxius, Gory); the pine bark aphis (Chernies pinicortis, Fitch); alder 

 aphis {Pemphigus tesselatus, Fitch); the cottony maple scale {Pul- 

 vinaria innumerahilis , Eath.); fall web worm {Hyphantria cv}nea, 

 Dru.); the poplar leaf beetle {Melastoma scripta, Fab.); "Curtis" 

 scale {Aspidiotus ostreaeformis) ; the scurfy scale {Chinoaspis fur- 

 fura, Fitch); the white marked tussock moth {Heterocampa leu- 

 costigma, Sm. and Abb.); the forest tent caterpillar {Melacosoma 

 disstria, Hubn.); willow^ saw flies {Cimbex americana, Leach, and 

 Pteronus ventralis, Say); the elm caterpillar {Euvanessa antiopa, 

 Linn.); the elm leaf beetle {Galerucella luteola, Mull.) — F. J. C. 



Veg-etation, Natural, as an indicator of the capabilities of 

 land for crop production in the Great Plains area. By H. L. 



Shantz {U.S.A. Dep. Agr., Bur. PI. Ind., Bull. 201; March 1911).— 

 Any attempt at arriving at the crop -producing capacities of new land 

 by examining the character of its native vegetation is almost certain to 

 lead to error if any single plant is taken as necessarily proving the 

 existence of any special characteristic of soil or climate. So many 

 things go to make up the sum of what a plant requires or will stand, 

 'ihe proportion or balance between all of these is often of so much more 



