. Circular. Insect pests; Insect pests. Fig. 4.—The alfalfa weevil: Eggs. Greatly enlarged. (Original.) killing them in their efforts to oviposit in them. Some idea of the abundance of these eggs and the extent to which the pest may breed in vacant lots and other waste lands where alfalfa has escaped from cultivation and grows as a weed ma}^ be obtained from the fact that in one case a single plant has been found to contain 127 of these egg punctures in the midst of the egg-laying season, with the punctures fresh and new. As one puncture may contain anywhere from a few to over 30 eggs, probabl
. Circular. Insect pests; Insect pests. Fig. 4.—The alfalfa weevil: Eggs. Greatly enlarged. (Original.) killing them in their efforts to oviposit in them. Some idea of the abundance of these eggs and the extent to which the pest may breed in vacant lots and other waste lands where alfalfa has escaped from cultivation and grows as a weed ma}^ be obtained from the fact that in one case a single plant has been found to contain 127 of these egg punctures in the midst of the egg-laying season, with the punctures fresh and new. As one puncture may contain anywhere from a few to over 30 eggs, probably 10 or 15 on the average, this single plant presumably contained between 1,200 and 1,300 eggs at the time it was observed. If these hatched and half of them developed into female beetles and 80 per cent of the latter passed the winter, this plant might in a year give rise to over 150,000 beetles. THE YOUNG. Most of these eggs (fig. 4, greatly en- larged) hatch in about 10 days after being deposited, and the minute young, almost white in color, make their way to the leaves, first eating holes therein, soon assume a de- cidedly green color, and when full grown are about one-fourth of an inch long, with a white stripe along the back and the some- what hooked appearance shown by some of those in the illustration (fig. 2). The attack is now confined to the young leaves and the crown of the plant, thus preventing its growth, and a badly infested field of alfalfa will fre- quently attain no greater height than about 6 inches, too short to mow at all. If the field is mown over most of the larvae will of course be shaken off and drop to the surface of the ground. While some of these perish, those that survive and live upon the fresh growth, together with those hatching from eggs deposited after the mowing, develop sufficient numbers to overwhelm and destroy the second crop. The larvae continue to attack the plants, being most abundant during May and graduallj' becoming less abundant
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectinsectp, bookyear1904
