Scientific American Supplement, No. 803, May 23, 1891 by Various
page 16 of 143 (11%)
page 16 of 143 (11%)
|
are not supposed to migrate very far.
Pulverized gas lime scattered along between the rows has been useful in keeping the flies away. Watering with liquid from pig pens collected in a tank provided for the purpose, was found by Miss Ormerod to be a better preventive than the gas lime. When the onions have been attacked and show it by wilting and changing color, they should either be taken up with a trowel and burned, or else a little diluted carbolic acid, or kerosene oil, should be dropped on the infested plants to run down them and destroy the maggots in the roots and in the soil around them. Instead of sowing onion seed in rows, they should be grown in hills, so that the maggots, which are footless, cannot make their way from one hill to another. THE CABBAGE BUTTERFLY. _Pieris rapae_ (Linn.) In the New England States there are three broods of this insect in a year, according to Mr. Scudder, the butterflies being on the wing in May, July, and September; but as the time of the emergence varies, we see them on the wing continuously through the season. |
|