. Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; . The pear-psylla.—a, pupa from under side, showing the thread-like piercing lancets; to the right, a winged adult and stalked egg. cicada. They all belong to the family Psyllidce, some species of which are exceedingly troublesome,—, the "pear-psylla," Psylla pyricola. This infests pear-trees in the more northern parts of the country, extending south to Maryland, though south of New York State it occurs in isolated patches only. It does its injury, first, by
. Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; . The pear-psylla.—a, pupa from under side, showing the thread-like piercing lancets; to the right, a winged adult and stalked egg. cicada. They all belong to the family Psyllidce, some species of which are exceedingly troublesome,—, the "pear-psylla," Psylla pyricola. This infests pear-trees in the more northern parts of the country, extending south to Maryland, though south of New York State it occurs in isolated patches only. It does its injury, first, by sucking the juices of the plant and so weakening it; second, it exudes honey-dew in such quantity as actually to close the pores of the leaves and young bark, over which a fungus forms and checks growth. It commonly attacks the stalk of the fruit, or the twig just where it is fastened, and the result is nearly always a cessation of growth in the pear itself. The species has several broods during the season, bift winters as
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectentomology, bookyear1
