Celticecis wellsi (Wells)

Phytophaga wellsi

Hosts: Celtis laevigata, occidentalis

Gall.--On underside of leaf, in vein fork, usually perpendicular to leaf, often single but may occur in twos and threes; turbinate, widest beyond midlength, the apex flattened with diminutive apical tubercle in center; surface green turning brown, covered with variable but usually thick, abundant white pubescence; ca. 4 mm long, almost as wide as long; apparent on opposite side of leaf as slight, sometimes discolored convexity; in cross section, walls thickest on distal half, yellowish, woody, thinnest at center apex; larval chamber elongate-ovoid, as long as gall.

Remarks. — Wells (1916) wrote that the gall was covered with short pubescence, but the specimens we have are more or less completely covered with long hairs, some crinkly. We suspect that Wells's specimen lost the hair through handling. In fact. Wells did not always note or draw hairs or draw them to their fullest extent. As examples, he did not draw hairs on galls of C. supina (Plate 1, Fig. 11) although that gall usually has hairs, and he drew what looks like very short pubescence for galls of C. celtiphyllia (Plate 2, fig. 9) when in fact they are usually covered with longer hairs. Felt (1916) wrote that the galls of C. wellsi were sparsely clothed with a whitish, appressed pubescence. This description agrees better with the galls we have seen.

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.]

Distribution (Map 21). — This species is known from the midwestern U.S. and Georgia, on northern hackberry and sugarberry.

GA, IL, IA, KS, KY, OH

Phytophaga wellsi

Top-shaped, monothalamous, moderately thick leaf gall, the surface sparsely clothed with whitish, appressed pubescence, the greatest diameter 3 to 4 mm.

Phytophaga wellsi Felt. Cecidium nov.

On leaf, under side, more or less definitely obconic, resembling the shape of a somewhat flattened top. Generally found in clusters attached to the sides of the principal veins near the point of their divergence from the petiole. 2.5-3 mm. high, 3-4 mm. wide. Distal end shows a more or less definite central prominence. Yellowish tinged, with short pubescence. Walls pithy in texture, yet firm; tissue when old, brown. Chamber sub-cylindric. Protective layer poorly developed, confined to proximal one-third of gall. Nutritive layer very thin. Fibro-vascular bundles traverse galls near the surface. This is the simplest of all the itonid galls studied.