Bul. 907, U. S. Dept. of Agriculture. PLATE IV. 
FUMIGATION OF CITRUS PLANTS WITH HypRocyYANiIc ACID. 
A, B, Fumigation injury to foliage at point of infestation with purple scale (Lepidosaphes 
beckii). The injury appeared most prominent on the side of the leaf opposite the in- — 
festation. A, Upper side of leaf, showing purple scale. B, Lower side of same leaf, 
showing collapsed tissue opposite scale infestation. C, Animmature Valencia orange 
injured by exposure to sunshine following fumigation. The uninjured area was 
shaded by leaves. D, Twig from a fumigated tree, showing how the leaves are ab- 
scissed at the base of the blade, leaving the petioles clinging to the tree. 
