. The Canadian entomologist. Insects; Entomology. THE CANADIAN ENTOMOLOGIST 307 belief that the species was erroneously described as a parasite of Icerya purchasi and is in reality a true parasite of Chrysopids. Certain studies of red-spider predators were conducted at Bates- burg, South Carolina, during the season of 1913, and it was noticed that a considerable percentage of the Chrysopas were parasitized. In order to determine the approxi- mate percentage of parasitism of these very beneficial insects Mr. F. 2 L. McDonough, of the Bureau of Entomology, and the writer, col- lected a large ser
. The Canadian entomologist. Insects; Entomology. THE CANADIAN ENTOMOLOGIST 307 belief that the species was erroneously described as a parasite of Icerya purchasi and is in reality a true parasite of Chrysopids. Certain studies of red-spider predators were conducted at Bates- burg, South Carolina, during the season of 1913, and it was noticed that a considerable percentage of the Chrysopas were parasitized. In order to determine the approxi- mate percentage of parasitism of these very beneficial insects Mr. F. 2 L. McDonough, of the Bureau of Entomology, and the writer, col- lected a large series of cocoons from JlllfcL-.^ cotton plants growing in the fields. Adults from these cocoons were c /^&B$L^' reared in the laboratory under con- ditions as nearly normal as possible. —Apical porti an of cotton phnt, shw- t, • rPrr,rHinn- m'nrP ing the characteristic location of *l IS WOrtn recording, blllLt Chrysopid cocoon at C wg haye neyer not[ce^ ft m print, that the Chrysopas in cotton fields pupate very characteristically in the apical buds at the very terminal portion of the stalk. The pubescence of the nascent foliage at this point is densely concen- trated and of a grayish appearance, thus approximating the texture of the cocoon and affording considerable protection for it. This is shown in the accompanying figure. Of course, occasional cocoons are found in other locations, as, for example, within the involucral bracts of "squares" or in the convolutions of leaves. These are exceptions. All of the several lots of Chrysopid cocoons collected were observed daily until they either produced adults or parasites, or until they clearly indicated that they were not going to give issue to anything. The final summary of results from this detailed study—in the case of the largest lot—is shown in Table 1. Table I.—Estimated Parasitism of Chrysopids. •*« WWWUHD1I0H c in nit cjm'iNitiitdHMiimHOiiimmiidii hoiiiwiiiiiiuih mown Diimiiiimuii ([i
Size: 1760px × 1420px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubje, booksubjectentomology
