. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. THE SPUING GRAIN-APHIS OB '' GREEN BUG.'' 51 REARING METHODS. All of the rearing work, unless otherwise stated in the text, was conducted out of doors under as nearly normal conditions as it was possible for us to secure. The wheat plants on which the Toxop- tera were confined were grown in flowerpots and covered with lantern globes, over the top of which was drawn a very thin fabric commercially known as swiss. The pots were placed on a rearing stand having one side hinged in such a manner that it could be let d
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. THE SPUING GRAIN-APHIS OB '' GREEN BUG.'' 51 REARING METHODS. All of the rearing work, unless otherwise stated in the text, was conducted out of doors under as nearly normal conditions as it was possible for us to secure. The wheat plants on which the Toxop- tera were confined were grown in flowerpots and covered with lantern globes, over the top of which was drawn a very thin fabric commercially known as swiss. The pots were placed on a rearing stand having one side hinged in such a manner that it could be let down in fair weather and closed up in case of gales or severe beating storms. This stand with its contents is illustrated in Plate II, figure 1. A thermograph was placed in this stand, and thus continuous records of temperature were secured. In the middle of the summer of 1907 two series of investigations were begun and were continued until De- cember to determine the number of generations. In both 1908 and 1909 series of generation studies were begun in spring with the egg (fig. 11) and continued until the egg-laying forms appeared in the fall. In making these observations, the first individuals to hatch from the eggs in the spring were isolated; the first-born from these were in turn isolated, and this process was continued throughout the season until the egg-laying forms ap- peared. The last-born was also kept and the same mode of procedure con- tinued until fall, as was the case in the line of the first-born. * All young other than the first-born of the first series and the last-born of the second series were counted each day and destroyed. In this manner, each series being considered, we would arrive at the maxi- mum and minimum number of generations. During these three years a vast amount of data, besides that on the number of generations, was thus accumulated. (See table, pp. 52-57.). Fig. 11.—The spring grain-aphis: Eggs as deposited on leaf: a, Dorsal view; 6, lat- er
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