. Annual report of the Agricultural Experiment Station. Cornell University. Agricultural Experiment Station; Agriculture -- New York (State). The Bronze Birch Borer. Igt The pest does not escape from parasitic enemies. While examining some infested branches of birch in January, 1899, I founrl several borers that had been killed by parasitic grubs. The parasite had spun a tough, semi-transparent cocoon inside the skin of its host. J^ater the adult para- site was bred and it proved to be the interesting little creature shown much enlarged in Fig. 38. It is a Chalcid fly known to science as Phas-
. Annual report of the Agricultural Experiment Station. Cornell University. Agricultural Experiment Station; Agriculture -- New York (State). The Bronze Birch Borer. Igt The pest does not escape from parasitic enemies. While examining some infested branches of birch in January, 1899, I founrl several borers that had been killed by parasitic grubs. The parasite had spun a tough, semi-transparent cocoon inside the skin of its host. J^ater the adult para- site was bred and it proved to be the interesting little creature shown much enlarged in Fig. 38. It is a Chalcid fly known to science as Phas- gonophora sulcata Westwood (Griffith's Animal Kingdom, Insects, \o\. II, p. 432). Note the wonderful development of the hind legs, the purpose of which is unknown. Chittenden also reared the same parasite from this borer and from the flat-headed apple-borer infesting a Japanese redbud tree. The parasites issued about two weeks after the beetles. Dr. Howard writes me that the parasite has been taken in Texas, California, Washington, D. C, Illinois, South Carolina, Canada, Florida and Oregon, thus showing a very wide distribution. Doubtless this interesting little. Fig. 3S.—Phasgonophora sulcata. The interesting little parasitic enemy of the bronze birch borer. Much enlarged. enemy aids materially in holding this bronze birch borer in check. But in most localities it has not yet reached that point where it is numerous enough to cope with the pest to the extent that man need not employ artificial agencies to prevent the destruction of his beautiful white birches. Remedial Suggestions. This bronze birch borer is practically invulnerable against man's usual insecticides. Nearly all of its life is spent as a borer under the bark out of reach of insecticides. The fact that the beetles feed for a few days on tender leaves would suggest spraying the trees in ]\Iay with a poison, but apparently they do not eat the birch foliage to any extent, preferring that of willow, poplar, or elm.
Size: 2435px × 1026px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., book, bookcentury1800, bookcollectionbiodiversity, bookdecade1880
