36 BULLETIN 190, UNITED STATES NATIONAL MUSEUM 



Male. — Antennae blue-black, pectinations fine, ferruginous. Labial 

 palpi smooth, lemon yellow, black at tips. Head black-violaceous. Collar 

 lemon yellow. Thorax black-violaceous ; patagia and posterior base well 

 marked with lemon yellow. Abdomen blue-black, segments 2, 4, and 6 

 broadly banded with yellow, segments 3 and 5 sometimes slightly dusted 

 or narrowly banded with yellow, beneath segments 2 and 3 blue-black, 

 4 to 6 yellow; anal tuft broad, fan-shaped, black, yellow in center, at the 

 sides and beneath. Legs yellow, femora shaded with dark purplish and 

 posterior tibiae purplish above and between the spurs ; tarsi purplish, 

 banded with yellow at the joints. Forewing transparent, costa and outer 

 margin moderately broad, violaceous-black, intermixed heavily with yellow 

 between the veins ; discal mark prominent, oblong, lustrous purple ; fringes 

 dull black ; underside with costa and inner veins yellow. Hindwing trans- 

 parent, narrowly bordered with black and yellow, fringes sordid black; 

 discal mark small, black. 



Female. — Larger than the male ; forewing with broader violaceous mar- 

 gins and a heavier shading of bright yellow on and between the veins. 

 Hindwing brightly bordered in thin lines purple and yellow, fringes dull 

 black. Abdomen with segments 1 and 3 blue-black, all other segments 

 bright yellow above and beneath; anal tuft a short blunt yellow brush, 

 touched with black in center and at the sides. 



Expanse : Male 20 to 22 mm., female 22 to 24 mm. 



Distribution. — Southern to central California, New Mexico. 



Type. — Female. Collected in Siskiyou County, Calif. In the United 

 States National Museum. 



Remarks. — This is a bark borer on sycamore and to a lesser extent on 

 live oak. The presence of the insect is revealed by numerous brown or 

 red pellets in crevices of the bark or in accumulations at the base of the 

 tree trunks. The tortuous galleries of the voracious larvae are within 

 the bark, rarely through the cambium layer into the solid wood. The 

 trunks of large, old trees are attacked in preference to young trees. My 

 personal records limit the range of this species to the California coastal 

 regions from San Diego to Santa Barbara. It has not been reported or 

 observed in northern California. Infestations, particularly heavy on 

 sycamore, were noted at Laguna Beach and in Arroyo Seco at Los 

 Angeles, extending to shade trees on adjacent streets and in gardens. 

 Attacks on live oak in the same region were less serious. The insect is 

 single-brooded, the larva wintering and pupating in spring in a.n oblong 

 cocoon of chips at the exit to the burrow. From bark sections obtained 

 early in the season the moths can be reared easily ; they emerge from May 

 to July. Examples reared from both sycamore and live oak in low 

 coastal regions unquestionably are one species. Sycamores at 2,000 feet 

 and over appear to be free from attack. Live oaks, on the other hand, 

 were found heavily infested at Buckman Springs, San Diego County, 



