Holly-Leaf Fly
(Phytomyza Ilicis). Holly leaves are very often disfigured by irregular pale blotches on the upper surface. These are spaces mined in the green cellular tissue, and are the work of the larvae of the Holly-leaf Fly. Usually, two or three larvae are to be found in a leaf, each in its own mine. They are under a line in length, yellowish-white, with black mouth. The small, oval, brown-ringed pupae may be found in the mine, covered by the lower epiderm of the leaf; and there they remain all winter, disclosing the flies in early summer of the next year. The fly is rather under one line long, black, with proboscis pale yellow, except the black palpi and hairs; knees and base of tibiae paler; wings transparent, much longer than abdomen. The most successful way to destroy the insects seems to be the removal and burning of the mined leaves; but this is hardly necessary, except in very select varieties of the plants, since the mines do not appear to cause much injury, unless very numerous.