. The insect book [microform] : a popular account of the bees, wasps, ants, grasshoppers, flies and other North American insects exclusive of the butterflies, moths and beetles, with full life histories, tables and bibliographies. Insectes; Insects. in The Gall-Flies gation by Kracmer. He finJs th:it ^'.illic acid is formed at the ex- pense of the starch during the chrysalis stage of the insect. With the maturing of the winged insect, the gallic acid is changed to tannic acid. The transformation of gallic acid into tannin is accomplished by the condensation of two molecules ol the for- mer wit
. The insect book [microform] : a popular account of the bees, wasps, ants, grasshoppers, flies and other North American insects exclusive of the butterflies, moths and beetles, with full life histories, tables and bibliographies. Insectes; Insects. in The Gall-Flies gation by Kracmer. He finJs th:it ^'.illic acid is formed at the ex- pense of the starch during the chrysalis stage of the insect. With the maturing of the winged insect, the gallic acid is changed to tannic acid. The transformation of gallic acid into tannin is accomplished by the condensation of two molecules ol the for- mer with the loss of one molecule of water. Most of these insects are single-brooded and develop but one generation in the year. Under unfavorable circumstances, how- ever, this period may be greatly lengthened, and circumstances are on record where the flies iiave emerged only alter two or three years. Certain moisture conditions favor the proper issuing, and when these are lacking the development is retarded. Some very curious alternations of generations occur among these insects. Of certain species, and indeed of certain genera. for years only the female sex was known, and it was afterward discovered, first by Riley and afterward by Adier, that what had been considered two entirely distinct forms were really the same species, but that one generation included both se,xes while the alternate generation comprised only females which reproduced parthenogeneticallv. One of the most peculiar connected with the gall-flies IS that a particular part of the plant is always affected by the same species, and that each species of the same generation always pro- duces a deformation or gall of exactly the same character, so that the gall alone identifies the species of insect, and in fact for a long time generic and specific names were given to the galls before the insects were named, the name subsequently being applied to the insect itself. The full development of none of the American gall
Size: 1057px × 2365px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectinsects, bookyear1901
