. Circular. Insect pests; Insect pests. the appearance of the first winged generation and its consequent migra- tion to hop, or (b) in the fall after hop-picking and after the lice have once more returned to the plum and are making their preparations for the laying of winter eggs. The latter time will, perhaps, be preferable, for the reason that in the fall the plum trees will be less susceptible to the action of the washes and a stronger solution can be applied without damage to the trees. (2) All wild plum trees in the woods through a. Fig. 5.—The Hop Plant-louse, male—enlarged. hop-growing
. Circular. Insect pests; Insect pests. the appearance of the first winged generation and its consequent migra- tion to hop, or (b) in the fall after hop-picking and after the lice have once more returned to the plum and are making their preparations for the laying of winter eggs. The latter time will, perhaps, be preferable, for the reason that in the fall the plum trees will be less susceptible to the action of the washes and a stronger solution can be applied without damage to the trees. (2) All wild plum trees in the woods through a. Fig. 5.—The Hop Plant-louse, male—enlarged. hop-growing country should be destroyed. (3) The hop vines should be either burned or thoroughly drenched with kerosene emulsion as soon after the crop is harvested as possible with a view of killing the males, and thus preventing the impregnation of the females. If these measures are carefully followed, comparative exemption from lice may confidently be expected. At the present time it is too late for preventive work, and the only thing which can be done to lessen the damage to the crop is to destroy the lice upon the vines by spraying with an insecticide mixture. Such spraying can, with care, be made quite effective, and the individual hop grower will have the satisfaction of knowing that whatever work he does upon his own yard will not be thwarted by the carelessness of neighbors, as during the summer the lice can not migrate except by cratvl- ingfrom one yard t'> another. Substances to be used.—Of all the different substances experimented with in 1888 none gave more satisfaction than properly prepared kero- sene emulsions and fish-oil soaps. Formula for kerosene emulsion. Cheap kerosene 8 Water ... 4 Soap 0^. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States. Bureau of Entomo
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Keywords: ., bookauth, bookcentury1800, bookdecade1890, booksubjectinsectpests
