NATURAL HISTORY, TORONTO REGION
Cecidomyia majalis, Bass. Hosts Quercus rubra, L., Quercus velutina, Lam. A flat, pouch-like gall on the under side of the leaves of the red and black oaks. It is clearly produced by a folding of the leaf, and in this respect resembles the Acarina and Hemipterous types.
Cecidomyia ocellaris, O.S. Host Acer rubrum, L. The red and yellow concentric rings of colour are a very noticeable feature of this gall. In a slight depression at the centre of these rings the larva rests covered with a viscid fluid secretion.
Cecidomyia pellex, O.S. Host Fraxinus americana, L. This gall is formed by a swelling of the blade of a leaflet on each side of the midrib of leaves of the white ash.
Cecidomyia triticoides, Walsh. Host Salix cordata, Muhl. A terminal gall produced by a swelling and shortening of the stem of this willow. The larval chambers are situated in the buds of the affected twigs.
Lasioptera impatientifolia, Felt. Host Impatiens biflora, Walt. A monothalamous gall consisting of a spindle-shaped enlargement of the midrib of leaves of the spotted touch-me-not.
Neolasioptera perfoliata, Felt. Host Eupatorium per f oliatum, L. A monothalamous gall on bone-set, consisting of a spindle-shaped swelling of the stem.