. Bulletin of the Department of Agriculture. Agriculture; Agriculture. 20 BULLETIN 124, U. S. DEPARTMENT OF of these parasites issued several days later, or 3 per cent. On July 28 Mr. Newton, encouraged by his first efforts, collected 31 eggs that appeared to be parasitized. Twenty-six of % these produced, in the course of five days, 76 parasites, or nearly 3 to each egg. Seventeen freshly laid eggs were exposed to female para- sites by Mr. Newton on August 1, and on August 8 eight of these produced 24 adult parasites, showing the length of the combined egg, larval, and pupa
. Bulletin of the Department of Agriculture. Agriculture; Agriculture. 20 BULLETIN 124, U. S. DEPARTMENT OF of these parasites issued several days later, or 3 per cent. On July 28 Mr. Newton, encouraged by his first efforts, collected 31 eggs that appeared to be parasitized. Twenty-six of % these produced, in the course of five days, 76 parasites, or nearly 3 to each egg. Seventeen freshly laid eggs were exposed to female para- sites by Mr. Newton on August 1, and on August 8 eight of these produced 24 adult parasites, showing the length of the combined egg, larval, and pupal stages to have been seven days. Nine failed to be parasitized, and one produced 5 parasites in six days. On August 16 Mr. lYilson collected 19 eggs, 60 per cent of which were parasitized. It is thus seen that this tiny parasite is of considerable benefit in reducing the numbers of the alfalfa caterpillar. From the records it seems that the increase of the parasites from July to August was quite rapid. The fact that the life cycle is of so short duration is partially responsible for this, as it doubtless gives a chance for two broods of parasites upon the eggs of one generation of Eurymus. HYMENOPTEROUS PARASITES OF THE CATERPILLARS AND CHRYSALIDS. Four species of hymenopterous parasites of the caterpillars and chrysalids were found. Specimens of a Linmerium were reared Fig. 7.—Trichogramma miniituni, a parasite of the eggs of the alfalfa butterfly, in act of oviposition in an egg of the hrown-tail moth (Euprootis chrysor- rhcea). Greatly en- larged. (From How- ard and Fiske.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States. Dept. of Agriculture. [Washington, D. C. ?] : The Dept. : Supt. of Docs. , G. P. O.
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