. 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. »' I i Fig 3 I«-irva' of Hupleitnis comstockii, on cotton caterpillar. I t'imrth A',irt C S. I:i!t. C'm. I The Chalcis Flies feeding extern;illy upon the p;:ill making larva, and there is a quite large group known as the Elachistinx which are parasitic upon caterpillars, the larvx of which feed also outside the skin of the host insect. It is one
. 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. »' I i Fig 3 I«-irva' of Hupleitnis comstockii, on cotton caterpillar. I t'imrth A',irt C S. I:i!t. C'm. I The Chalcis Flies feeding extern;illy upon the p;:ill making larva, and there is a quite large group known as the Elachistinx which are parasitic upon caterpillars, the larvx of which feed also outside the skin of the host insect. It is one of these which has been selected for our typical life history. It was studied in the summer of 1878 in the cotton fields of Alabama by Mr. H. A. Schwarz, but it has a north- ward spread and is parasitic upon caterpillars of certain Geomet- rid moths âmeasuring uorms. The adult parasite, which is a little black, shiny, four-winged fly and which, when seen under a strong lens has a number of strong, dark colored bristles upon its back, lays its eggs to the number of from three to fifteen in .1 group upon the middle of the back of the wriggling caterpillar. Each egg is brown in color, almost black before hatching, is elongate oval, strongly above, and somewhat llattened heneath. The individual eggs although laid in a group are sufficiently separated from each other to allow for the development of the larv;e. They hatch about two days after being laid. The delicate egg shell splits longitudinally in the middle of the back and discloses the white, grub-like parasite larva, which gradually works the egg shell more and more down the sides of its body where it remains visible as a black line for some hours. As soon as the grub has freed its head from the egg shell it pierces the skin of the victim, and thereafter remains stationary with its head buried. As soon as it has fairly begun to feed, the white color changes to a bright bluish green, and the spiracles and the con-
Size: 2289px × 1092px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectinsects, bookyear1901
