CLEAR-WING MOTHS OF FAMILY AEGERIIDAE 115 



Alalc. — Antennae steel-blue-black, with a golden spot at the base beneath. 

 Palpus yellow, the third joint often, but not always, tipped black. Head 

 black, orbits shining white. Collar yellow above, white at the sides and 

 beneath. Thorax black, lustrous steel blue or coppery, with a narrow, 

 long, yellow stripe on the patagia and a small yellow transverse patch 

 posteriorly. Abdomen steel blue or violaceous-black, segment 2 narrowly 

 banded with yellow above; segment 4 above also with a narrow yellow 

 band, which broadens on underside; segments 5, 6, and 7 yellow beneath; 

 a thin yellow stripe below on the side from base of abdomen to segment 

 2; anal tuft nicely fan-shaped, black, edged vvith yellow at the sides. 

 Anterior coxae bright golden yellow ; femora blue-black ; tibiae yellow, 

 banded with purplish black between the spurs ; tarsi yellow, with narrow 

 blackish bands at the joints. Forewing transparent, veins, discal spot and 

 narrow, outer border blue-black ; golden-yellow rays between the veins 

 from the margin inward ; costa blue-black, intermixed with yellow ; under- 

 side yellower than upper. Hindwing transparent, margins very narrowly 

 blue-black. Genitalia having sacculus with strong spines in a straight line. 



Female. — Like the male but larger and stouter ; the yellow shading on 

 forewings heavier; abdominal segment 2 edged with yellow posteriorly, 

 sometimes with a yellow stripe on the side to the base of abdomen ; seg- 

 ment 4 broadly banded with yellow above and beneath ; segments 5 and 6 

 yellow beneath ; anal tuft short, inverted from the sides, center black, edged 

 broadly with yellow. 



Expanse : Male 14 to 18 mm., female 16 to 20 mm. 



Distribution. — Southeastern Canada and New England, westward to 

 Ohio, Illinois, and Minnesota and southward to the Mississippi Valley and 

 into Texas. Not known from the Rocky Mountain regions and the Pa.cific 

 coast. 



Type. — Female ( T. W. Harris) . In Boston Society of Natural History. 



Remarks. — No other species in the family Aegeriidae exhibits so great 

 an adaptability to dififerent unrelated food plants as scitiila. Normally a 

 bark borer on oaks, it has been found to attack all sorts of deciduous trees 

 and shrubs and even pine, provided there are physiological conditions to 

 attract the insects. These are abnormal growths such as woody galls, 

 excrescences due to fungi, rusts, and blights, bruises, and healing wounds. 

 Under favorable conditions extremely heav)' infestations result. The 

 cynipid gall, Andricus cornigerus, often occurring in thousands on single 

 trees of black and pin oaks, may be heavily attacked, nearly every gall 

 serving the clearwing borer as a habitation. A similar condition has been 

 observed in the case of hickory trees in Texas that were laden with hard, 

 woody galls. A larger, bulging growth on the trunk of a beach near 

 Mobile, Ala., produced hundreds of the moths, judged by the protruding 

 pupal exuviae. Likewise in pecan groves in northern Florida and in 

 Alabama distortions at the bases of tree trunks due to a fungus were 



