. Annals of the Entomological Society of America. Entomology. plant food used was that known to plant physiologists as Pfeffer's solution and is prepared as follows: Calcium nitrate 4 grams Potassium nitrate 1 gram Magnesium sulphate 1 " Potassium dihydrogen phosphate 1 " Potassium chloride " Ferric chloride Trace Distilled water 3 to 7 liters* The plants grew well in this solution, although at times some difficulty was en- countered by the growth of algae in the liquid. This was largely overcome, however, by painting the bottles black. Usually the plants lived long enough f
. Annals of the Entomological Society of America. Entomology. plant food used was that known to plant physiologists as Pfeffer's solution and is prepared as follows: Calcium nitrate 4 grams Potassium nitrate 1 gram Magnesium sulphate 1 " Potassium dihydrogen phosphate 1 " Potassium chloride " Ferric chloride Trace Distilled water 3 to 7 liters* The plants grew well in this solution, although at times some difficulty was en- countered by the growth of algae in the liquid. This was largely overcome, however, by painting the bottles black. Usually the plants lived long enough for experimental purposes without changing the liquid. When the experiments were prolonged the solution was changed as often as necessary. By using this method, it was possible ^^ to follow the life history of the Hessian fly <^ from oviposition to the formation of the C puparium. The plants could be handled conveniently and the various stages studied with greater ease and exactness than when the plants were grown in the soil. When necessary, the plants could be removed from the bottle and placed under the binocular for close study. By carefully shaving the epidermis of the leaf sheath, it was possible to keep the larvae under observation at all times. As the larvae increased in size they could readily be seen through the neck of the bottle. This method proved so successful in the Hessian fly work that it was adopted for J r . Wheat plant growing the study of a number of other insects in a nutrient solution. infesting cereal crops. Thus far the writer . C-Cell for confining fe i- insects on the plant. has grown wheat, oats, rye, barley, corn, and many of the sorghums in Pfeffer's solution in connection with studies of the chinch bug {Blissus leucopterus Say), green. Fig. i. * The writer has found that five liters is best for the work under Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectentomology, bookyear1
