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Show "Hopping Louse" Injures Spud Crop That the "hopping plant louse," an insect scientifically known as Psyl-! lia, is in some way the cause of the j disastrous potato disease that swept 1 over Utah the past summer, has been; proved by Dr. B. L. Richards, plant I pathologist of the Utah Experiment j station and in charge of botanical 1 work at the Utah Agricultural college. col-lege. The disease caused by this insect in-sect ravaged hundreds of fields in 1 Utah last summer causing a loss of thousands of dollars. Only about CO per cent potato crop is being harvested har-vested in this section. The disease spread so rapidly and was so pecu-1 liur that plant pathologists of the entire country were at a loss to offer an explanation. Dr. Richards determined the cause of the disease by careful experiments at the college. He secured clean seed from Oregon and covered the plants with insect proof cages. Only those plants where the insect was introduced into the cages had any symptom of the disease, all other covered plants being perfectly healthy. heal-thy. Though part of the experiment was conducted in the greenhouse the results were the same with seed j planted in open fields and subjected to the same treatment. The exact manner in which the Insect In-sect causes the disease is unknown, j There are numerous grounds for the assumption that the insect on punc- turing a potato plant injects a virus or poison which produces the disease. Thus the insect would act as a carrier as the mosquito carries malaria fever and the leaf hopper carries the virus that produces curly top in sugar beets. According to Dr. Richards the leaves of the affected plant begin to change color and curl about ten days j after the insect punctures the plant, j New branches and tubers begin to j grow at the axis of the leaf and the ! underground tubers stop growing. : They then germinate and a secondary growth of tubers is formed so thatj in some sections a small crop of little j potatoes may be harvested. An ap- parent rosette of leaves appears at the axis of the leaves or at the top of the plant. The result is the most j i disastrous potato disease that has J I ever hit the potato plant or possibly ! ! any other farm crop. j 1 The discovery of Dr. Richards, the ' , first to assign the cause of the disease, dis-ease, will give a foundation for work leading to the control of the disease. 1 Pathologists are giving every attention atten-tion to the problem of control not only because of the present state of disease but also because of its alarm- ing possibilities of spreading which : it exhibited last summer. |