. Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; . Cabbage-maggot, Phorbia brassica.—a, larva ; b, pupa ; c, adult; d, its head ; e, antenna. injurious to cabbage and cauliflower, as well as to onions, rad- ishes, turnips, beets, and other root crops, while other species attack planted seeds like those of melons ^^^- 4'9- and even corn. Oc- casionally, instead of attacking roots, the maggots are found boring in thick or fleshy leaves, and then they make mines or galleries be- tween the upper and lower surfaces, often do
. Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; . Cabbage-maggot, Phorbia brassica.—a, larva ; b, pupa ; c, adult; d, its head ; e, antenna. injurious to cabbage and cauliflower, as well as to onions, rad- ishes, turnips, beets, and other root crops, while other species attack planted seeds like those of melons ^^^- 4'9- and even corn. Oc- casionally, instead of attacking roots, the maggots are found boring in thick or fleshy leaves, and then they make mines or galleries be- tween the upper and lower surfaces, often doing much injury. Sometimes their hab- its are more hke those of the house- fly, and the larvae are scavengers, while a few have been recorded as parasites on other insects. The group, therefore, is one with diverse habits, but usually to be looked upon with considerable suspicion. Perhaps the best known of the root-maggots is the larva of Phorbia brassicce, in- festing cabbage, cauliflower, and other plants of the same natural family. Eggs are laid on the ground soon after the plants are set out in the fields. The larvce make their w^ay into them as soon as they are hatched, gnawing or rather scraping the tissue, so as to enable them to absorb the plant juices, for they have no jaws for mastication. Decay sets in where the insects work, and this favors their feeding, so in a few days they destroy the tissue of the plant and stem a little below the surface so completely that it dies. Later crops are not so much harmed, as a rule, and if plants can be preserved until they reach a good size, they fre- quently sustain considerable maggot attack without serious in- jury. As to the best remedies against this particular insect we are yet somewhat uncertain. Putting a pad or disk of tarred paper on the stems of the plants when they are set out has been found successful in preventing the adult from laying eggs, or the
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectentomology, bookyear1
