72 BULLETIN 190, UNITED STATES NATIONAL MUSEUM 



the costa showing a denser scattering of yellowish scales. The anal tuft 

 short, deep orange. Color patterns, so contrasting on freshly emerged 

 specimens, unavoidably become blurred or lost in the cabinet. A confusion 

 with Conopia acerrubri can always be a.voided by comparison of the male 

 genitalia. 



Expanse : Male 15 to 18 mm., female 18 to 24 mm. 



Distribution. — Eastern Atlantic Coast States. 



Type. — Male. In the American Museum of Natural History. 



Remarks. — Reared from the roots and basal parts of stalks of Doellin- 

 geria umbellata (tall, flat-topped white aster) late in May and early in 

 June 1921. The insect is a fairly common species along the borders of a 

 swampy region at Woodhaven, Long Island, N. Y. The males fly about 

 actively on bright, sunny days, while the more sluggish females, resting on 

 or near the food plant, can be taken with a killing bottle. The eggs are 

 laid singly on the lower stems of the food plant, and the young larvae work 

 downward through the pith to the root, attaining full growth late in fall. 

 At this time also preparations are made for the change to pupae early in 

 May by enlarging the larval gallery from the root upward for 2 or 3 

 inches, where the stalk is weakened by inner, circular incisions and the gal- 

 lery capped with f rass. Just below the weakened part of the stem a round 

 hole thinly capped with plant tissue provides an easy exit for the moth, 

 which emerges two or three weeks after pupation. Stems weakened by 

 incisions invariably break off during winter storms, leaving clean-cut, 

 short, upstanding stumps, easily recognized by the collector when looking 

 for pupae. Quick action is needed, though, for the pupa is capable of mov- 

 ing up or down and will descend well into the root upon disturbance. This 

 provision no doubt also is of advantage to the larva and pupa at times 

 when the swamps are flooded. It is a habit characteristic of many of the 

 root borers in herbaceous plants. Larvae that have not transformed to 

 pupae by the end of May usually are found to be parasitized. 



At Woodhaven, Long Island, more than a hundred specimens were ob- 

 tained by rearing or collecting. The species in general follows the dis- 

 tribution of its food plant in Eastern and Midwestern States. 



The name corni was suggested by the capture of the type on Cornus 

 sericea in Purgatory Swamp near Boston, Mass. Subsequent to the de- 

 scription in 1881 this borer in the roots of asters was confused with another 

 species (acerrubri) bearing some external resemblance but a wood borer 

 in maple, principally red maple. Under the misapplied name of corni this 

 form has received considerable attention as an economic species, while the 

 true corni has been ignored. Worn and greasy examples of the two species 

 in mixed collections are confusing. For accurate determinations it is nec- 

 essary to compare the male genitalia. In corni the vinculum is long and 

 slender and the sacculus ridge of harpe is densely and broadly scaled to a 

 recurving pocket at the margin ; in acerrubri the vinculum is shorter and 



