146 BULLETIN 190, UNITED STATES NATIONAL MUSEUM 



specimens differ chiefly in the stripe on the tegulae. In simulans it is short, 

 confined to the lower half ; in palmii it extends over the whole length from 

 the collar to the metathorax. Intermediate phases suggest the possibility 

 of hybridization, but this has not been proved. Numerous experiments 

 in exposing virgin females to attract males have not been successful. 



The capture of a moth is a rare and interesting experience. During 

 flight the adults are almost indistinguishable from queens of species of 

 Vespa, which they simulate, even when at rest on tree trunks, by nervous 

 movements of the abdomen. One would hesitate to attempt capture one by 

 hand. The fine, long series in the United States National Museum and 

 in the writer's collection have been obtained by rearing. In a natural 

 undisturbed habitat the larval burrows, easy to recognize, are scattered and 

 oftener than not are empty, the larvae having been extracted by wood- 

 peckers. For collecting in numbers favorable conditions have been pro- 

 vided by the clearing of woodlands near cities and towns, followed by 

 the growth of young shoots and saplings, which are particularly attractive 

 to the insect. The life cycle is two years, and curiously this has remained 

 so fixed that in the Eastern States it is almost useless to hunt for wood 

 cuttings containing mature larvae or pupae in years of uneven numbers ; 

 in the even years they are abundant. The young larva begins a shallow 

 excavation under bulging bark, which it enlarges in the spring before 

 tunneling into the solid wood to a depth of about 2 inches. In prepara- 

 tion for a pupal chamber the tunnel is capped at the outer end in the fall ; 

 the transformation to pupa does not take place until late in the spring 

 of the second year. 



In distribution the species may be said to follow its food plants, which 

 are black, red, and pin oaks, north to Nova Scotia and eastern Canada, 

 south to Virginia and west to Minnesota. Records of capture and rearing 

 are most numerous from Long Island, the vicinity of New York City, and 

 New Jersey. Several specimens in the collection of the Boston Society of 

 Natural History are from Maine (Johnson). 



The male type of luggeri was bred from red oak at St. Paul, Minn., by 

 Professor Lugger, who states that the insect is injurious to the trees. 

 His description and figure clearly apply to an example narrowly banded 

 with black on the abdomen. In the Eastern States, this variation is re- 

 placed largely by a color form marked much more broadly with black on 

 the anterior abdominal segments. Among hundreds of specimens exam- 

 ined four of the darker form occur to one of the paler. The former is 

 regarded as simulans. Grote's description of the female type of simulans 

 from Algonquin, 111., indicates an example intermediate between the two. 

 There is one rearing record from chestnut, Castanea dentata, a female 

 from Brooklyn, N. Y., June 22, 1903 (Engelhardt). This specimen is 

 normal for simulans, except that the body color is not yellow but deep 

 orange. 



