Economic entomology for the farmer Economic entomology for the farmer and fruit-grower economicentomolo01smit Year: 1906 THE INSECT WORLD. 339 The '' pear-midge,'' Diplosis pyrivora, is an imported species appearing- with the first buds of early spring and ovipositing in them as soon as they begip to show white. The young larvae make their way to the ovary or seed-capsule of the setting fruit, and when this reaches the size of a nut, growth stops. The pears are then irregular in shape, a little knotty, and filled in the centre with a mass of orange-yellow larvse. In June these become full- gr
Economic entomology for the farmer Economic entomology for the farmer and fruit-grower economicentomolo01smit Year: 1906 THE INSECT WORLD. 339 The '' pear-midge,'' Diplosis pyrivora, is an imported species appearing- with the first buds of early spring and ovipositing in them as soon as they begip to show white. The young larvae make their way to the ovary or seed-capsule of the setting fruit, and when this reaches the size of a nut, growth stops. The pears are then irregular in shape, a little knotty, and filled in the centre with a mass of orange-yellow larvse. In June these become full- grown, leave the pears,—which now ^'^- ^S^- crack open and de- cay,—and drop to the ground, beneath the surface of which they pass the winter. The insect is es- pecially fond of the '' Lawrence'' va- riety, and where such can be found in sufficient num- bers, all others are exempt. The way in which this species can be controlled is by treating the ground beneath in- fested trees with a heavy 'top-dressing of kainit,—say one ton to the acre,—applied between the middle and end of June. Planting 'Lawrence' trees as traps and applying the above remedy to the soil beneath them will decidedly lessen the injury to the balance of the orchard, or their fruit may be gathered and destroyed in May, with all the contained larvae. Not all the gall-midges are injurious, however. Many species form galls or other distortions of growth on weeds or other plants of no special economic interest, or in such a way as to cause no real injury, and a few are actually predaceous and directly bene- ficial. Such is the species that feeds in the Phylloxera leaf-galls The pear-midge, Diplosis pyrivora.—a, female adult; pupa ; other references are to structural details.
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