. Biennial report of the Oregon State Board of Horticulture ... Horticulture -- Oregon; Fruit-culture -- Oregon; Gardening -- Oregon. APPENDIX. 39' renoe on over thirty dilTerent plants in Europe. Certain stone fruits and the pear, jjarticularly the latter, are their especial favorites. LIFE-HISTORY AND T .-'^^^^^^^'^^'^^r^ jv#.~ Fig C 2—Pear sluff, illustrating mothf)d of oviposi- tion and oiiiergeiice of larva; a, cutting of cell beneath epidermis, with ovi^wsitor; h, same after e;jg has been deposited; c, same after escape of larva—enlarged (original). The parent fly may be seen on
. Biennial report of the Oregon State Board of Horticulture ... Horticulture -- Oregon; Fruit-culture -- Oregon; Gardening -- Oregon. APPENDIX. 39' renoe on over thirty dilTerent plants in Europe. Certain stone fruits and the pear, jjarticularly the latter, are their especial favorites. LIFE-HISTORY AND T .-'^^^^^^^'^^'^^r^ jv#.~ Fig C 2—Pear sluff, illustrating mothf)d of oviposi- tion and oiiiergeiice of larva; a, cutting of cell beneath epidermis, with ovi^wsitor; h, same after e;jg has been deposited; c, same after escape of larva—enlarged (original). The parent fly may be seen on the pear or other trees which serve as food for the larvfe very early in the spring-. In Washing-ton, D. C, the present season they were observed on the newly-expanded leaves by the middle of April actively engaged in laying their eggs. In the latitude of Boston and northward the flies do not ap- pear much before the middle of May, and the egg-laying is chiefly during the latter part of May and the first of June. Judging from our experience here many of the eggs laid by the flies which appear in April perish during the cold, wet weather which often charac- terizes this month. This was the case the present season, few. if anv. of the eggs first deposited producing larvse. But one egg is doposited in a place, and it is always inserted from the under side of the leaf. The ovipositor is thrust obliquely through the leaf to the upper epidermis, but not piercing the latter, and shows there dis- tinctly through the transparent upper skin of the leaf, as represented in the accompanying illustration (Fig. 2), while the insect otherwise is completely hidden. The saw-like instrument, when brought into the position noted, is moved rapidly with a swinging lateral motion from side to side, cutting the upper epidermis free so as to form an irregular cell or pocket of peculiar flattened ovoid outline. The egg is quickly passed down between the plates of the ovipositor and dropped into the
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