Celticecis pyriformis Gagne, new species

Unnamed species, Riley 1890

Hosts: Celtis occidentalis

Gall.--Attached singly or serially to more prominent leaf veins on underside of leaf, occasionally adjacent galls partially fused; generally cylindrical, becoming bulbous at base, upright to recumbent, apex flat except for short central nipple; green turning yellow, sparsely to densely covered with long, crinkly white hair of variable length; 3–4 mm long and 2–3 mm broad at base; connection to vein conspicuous, often causing swelling of vein nearby and appearing as a convexity on opposite side of leaf; mature gall in cross section woody, wall of uniform thickness or thickest basally and thinning beyond mid-length, larval chamber elongate ovoid, nearly as long as gall.

Affinities. — See discussion under C. pubescens. [C pubescens and two others, C. pyriformis and C. wellsi, appear to be related. All three cause upright, columnar, woody, more or less hairy leaf galls that are attached to veins, Celticecis globosa may also be related to these three. The gall of C. globosa is also upright and woody but the larval chamber is ovoid instead of columnar and the larva itself is flatter and more deeply sulcate between segments.]

Biological note.--In Maryland galls were first found in early June already with yellow second instars. By mid-July some galls contained either second or third instars and in mid-August larvae were in the third instar and the larval chambers were lined with silk. Once, at Falling Waters, West Virginia, a gall contained a predaceous Lestodiplosis larva feeding on the C. pyriformis larva. A hole was present at the base of the gall, but it is doubtful that the Lestodiplosis made the hole.

Distribution (Map 15). — This species is known only from northern hackberry and has a northerly U.S. distribution, from Kansas to Maryland.

KS, KY, MD, IL, MO, OH, WV

Celticecis pyriformis

In this study, C. pyriformis was found at three study sites in Pennsylvania, and the two study sites in New Jersey (Figure 8) representing two newly recorded state records for the distribution of this species.

[No name given]

35. Cecidomyidous galls on the under side of the leaf arising from the leaf-veins, either singly or in groups or in rows, either assuming a vertical position or more or less reclining or even horizontally placed. Gall cylindrical, or very slightly narrowed at base ; at tip always truncate with a median nipple. Color pale yellow, surface opaque, faintly longitudinally striate and usually beset with sparse, long, white hairs, which, however, are easily lost. Average height of gall, 2.5mm; diameter, 1.2 mm. The walls are thin, the cell elongate with the apical side truncate, and the basal end conical. On the upper side of the leaf the gall is barely visible as a small yellowish spot on the veins.

This often occurs in company with the preceding species, of which it may possibly be an extreme but constant variety: at least a form which combines the characters of the two is not infrequent. It is intermediate in size, short, conical, with truncate tip and either hairy or glabrous.

13. Cecidomyia sp.

"Leaf gall, present in great numbers on under side. A "peg-shaped" gall, cylindrical when young, and developing a thickened base as it grows. Pale green, straggling hirsute, 2-3 mm. long. Very common." Sears.

The broad, ill-defined ridges which characterize the base of this gall separates it from all others. The protective layer is relatively thick, but does not extend into the wall of the distal end. The nutritive layer is thin. The fibro-vascular bundles pass through the parenchyma basally but approach the protective layer apically. Young specimens of this gall would closely approximate the gall described in Riley's report under No. 30 [Celticecis oviformis]. The expanded condition of the base is not gained until the gall has nearly completed its growth in length.