. Bulletin. Agriculture; Agriculture -- Arizona. Fig. 26—Hymenopterous parasite attacking an Fig. 27—Parasitized specimens of aphis. the lady birds at the time of the first serious outbreak is quoted to emphasize the impracticability of relying upon these natural enemies for the control of the cotton aphis in midsummer: "On August 19-20, 1914, a visit by the State Entomologist to numerous cotton fields on both the California and Arizona side of the Colorado River near Yuma disclosed the fact that all kinds of natural enemies were scarce, particularly the lady-bird noted above. In
. Bulletin. Agriculture; Agriculture -- Arizona. Fig. 26—Hymenopterous parasite attacking an Fig. 27—Parasitized specimens of aphis. the lady birds at the time of the first serious outbreak is quoted to emphasize the impracticability of relying upon these natural enemies for the control of the cotton aphis in midsummer: "On August 19-20, 1914, a visit by the State Entomologist to numerous cotton fields on both the California and Arizona side of the Colorado River near Yuma disclosed the fact that all kinds of natural enemies were scarce, particularly the lady-bird noted above. In some fields there had been a decrease in the number of aphis due to internal parasites. In several infested fields large numbers of convergent lady-birds had been liberated some weeks previously. Wherever this had been followed by a decrease in the amount of aphis the introduction of the natural enemies was generally cred- ited with the supposed benefits. A close examination, however, showed that these introductions could have had no beneficial effects whatever since the lady-birds in any stage were as scarce in these fields, which had been stocked with the beneficial insects, as in fields which had not been so supplied. Furthermore, an examina- tion of the plants failed to disclose any evidence of the lady-birds having bred in the fields. Such evidence would have been easily found in the presence of large numbers of pupae or empty pupal ^Sixth Annual Report Ariz. Comni. Agr. & Hort., pp. 37-38, 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 University of Arizona. Agricultural Experiment Station. Tucson : Agricultural Experiment Station, University of Arizona
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