About Arsacia rectalis (Walker, 1863)
Palpi of Arsacia rectalis are porrect, meaning they extend forward. The second joint of the palpi is thickly covered in scales, while the third joint is very small and sharp-pointed. A frontal tuft is not present. In males, the antennae are almost simple. The thorax and abdomen are smoothly covered in scales. The tibia is hairless. The forewings have a quadrate apex, and the outer margin of the forewings is rounded. The inner margin is lobed, and carries slight tufts of hair near the base and at the outer angle. Veins 7, 8, 9, and 10 of the forewings are stalked. The wingspan of Arsacia rectalis ranges from 14 to 18 mm. Adult moths have been recorded on wing in March. The head and thorax are rufous in color, and the abdomen is fuscous. The forewings are bright chestnut, and the costa is suffused with pink. An oblique line runs from the apex to the middle of the inner margin; the area beyond this line is suffused with pink, and has an indistinct series of dark scale patches along the sub-marginal and marginal regions. The hindwings are dark fuscous.
