[180] Beutenmüller, W. Sesiidae of America, etc. 266-271. 1901.
[181] Ibid. 291-292. 1901.
[182] Riley, C. V. An. Rpt. State Entomol. Mo. 1:46-47. 1869.
[183] Lowe, V. H. N. Y. Sta. Bul. 180:122-128. 1900.
[184] Wilson, H. F. The Peach-tree Barkbeetle U. S. D. A. Bur. Ent. Bul. 68:91-108. 1909.
[185] Hunter, W. D. The Aphididæ of N. A. Ia. Sta. Bul. 60:103. 1901.
[186] Ibid. 107, 108.
[187] Ibid. 108, 109.
[188] Gillette, C. P. A Few Orchard Plant Lice Col. Sta. Bul. 133:41. 1908.
[189] Ibid. 39.