. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. THE PEAR THRIPS. 7 ing eggs on such plants. The insect has proved itself a strictly fruit- tree pest, and it is carried to weeds and lives on them or on other plants only by accident. LIFE HISTORY AND HABITS. THE EGG, THE OVIPOSITOR, AXD OVIPOSITION. The thrips egg is bean-shaped (fig. 2), light-colored, almost trans- parent, and is very large in proportion to the size of the abdomen when seen within the body of the adult female. It is about mm. long by actual measurement. The ovipositor (fig. 3) is made up
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. THE PEAR THRIPS. 7 ing eggs on such plants. The insect has proved itself a strictly fruit- tree pest, and it is carried to weeds and lives on them or on other plants only by accident. LIFE HISTORY AND HABITS. THE EGG, THE OVIPOSITOR, AXD OVIPOSITION. The thrips egg is bean-shaped (fig. 2), light-colored, almost trans- parent, and is very large in proportion to the size of the abdomen when seen within the body of the adult female. It is about mm. long by actual measurement. The ovipositor (fig. 3) is made up of four distinct plates. Each plate is pointed, has a serrate outer edge, and is operated by powerfid muscles and plates within the abdomen. The pairs on each side fit together along the inner edges with a tongue-and-groove-like structure, which in action renders possible a sliding back and forth, or sawing motion. The ovipositor is protected within a sheath in the ventral tip of the abdomen when not used, but before and during ovipositing it is lowered until almost at right angles to the body. Oviposition accompanies feeding. It seems necessary, indeed, that before the ovipositor can be inserted through the plant epidermis the thrips must first weaken or break an opening through this tissue with the mouth-parts. The successive operations of lacerating the plant tissue, lowering the ovipositor, placing an egg, and withdrawing the ovipositor require from four to ten minutes, and may be briefl}' described as follows: After making an incision with the mouth parts the insect moves forward, lowers and inserts the ovipositor, and by operating the tiny saws she makes a deep incision in the plant tissue. While the ovipositor is still deeply set in the plant, an egg is con- ducted through the cavity between the plates and deposited under- neath the epidermis. The ovipositor is withdrawn and the egg is thus left deeply embedded within the plant. During the oviposition period one often fi
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