CLEAR-WING MOTHS OF FAMILY AEGERIIDAE 177 



Records in the "Catalogue of Insects Found in New Jersey," 1890 

 (John B. Smith), Riverton, September 9, and Browns Mills, Sep- 

 tember 15 (Daeke collector), are misidentifications and apply to Bem- 

 becia emarginata. 



Type. — Female. In the Boston Society of Natural History. 



Remarks. — Aegeria apijormis and tibialis are two closely related species 

 with indentical food plants and habits, the first a European native, re- 

 cently emigrated to the United States, and the second an indigenous 

 American species. Overlapping in the distribution of the two species 

 has not yet occurred. In the very large collection of tibialis at the United 

 States National Museum it is notable that most of the moths are from 

 western and Pacific coast regions, with no examples from the type locality 

 in New Hampshire and only a few from Massachusetts and New York, 

 none obtained by rearing. Typical specimens are one male, Monterey, 

 Mass., July 15, 1923 (C. A. Frost), and one female, Ithaca, N. Y., 

 July 9, 1937 (H. F. Scudder). Two, representing dark variations, male 

 and female, are from Keene Valley, Adirondacks, N. Y., July 29, 1911 

 (Howard Natman). 



While generally distributed along the north Atlantic coast, places of 

 infestation are difficult to find until after the moths have emerged, leaving 

 as evidence their pupal exuviae at the bases of the trees or on ex- 

 posed surface roots. Such records have been furnished by William 

 Procter from cottonwood. Bar Harbor, Maine, 1938, and by the writer 

 from balsam poplar, Dublin Shore, Nova Scotia, 1919. In western and 

 Pacific Coast States the insect is far commoner and at times a menace 

 to poplars, mostly in settled rather than in wild undeveloped country. 

 A serious outbreak on cottonwood in a park section of Sacramento, Calif., 

 was reported by B. G. Thompson, of Corvallis, Oreg., in 1921. From 

 wood and root sections of the stunted and dying trees he reared many 

 of the moths during June, some emerging from sections several feet 

 above ground. In extensive field examinations I always have found the 

 larval burrows confined to the bases of trees or to roots. Heavy infesta- 

 tions on cottonwood also have been reported by Ralph Hopping, of 

 Vernon, British Columbia, for the Vancouver region, and I found the 

 borer extremely common in Arroyo Seco, Los Angeles, Calif., in 1928. 

 Food plants rather than climatic conditions appear to influence distribu- 

 tion in the West. The insect occurs from sea level to near timber line, 

 attacking quaking aspen with preference at high elevations. A female 

 captured while emerging and confined in a screened box outdoors, Beaver 

 County, Utah, July 1914, in two days attracted some 200 males during 

 the morning hours and the early afternoon. The moths came buzzing 

 like bees over a hive. J. H. Newton, State entomologist, reports a similar 

 experience from Paonia, Colo., August 1917. A reared female, freshly 

 emerged and stupefied with chloroform for photographing on a table out- 



