ITONIDIDÆ.

3. Caryomyia nucicola, O. S.

“Irregular swelling in the husk produced by the reddish larvæ. Reference to Caryomyia provisional.” Felt. “Contain thick walled cells. On Carya (Hicoria) alba.” Jarvis.

4. Cecidomyia cynipsea O. S.

“Rounded, irregular, hard swelling on the under side of the hickory leaf, on the mid-rib near the base of the leaf about half an inch long. In July, pale yellowish and contained in several small hollows, minute whitish larvæ, with breast bone narrowed anteriorly and ending in a point.” Osten Sacken.

This form is so different from the other itonid galls of the hickory that the writer is inclined to place it here tentatively. It is very similar to Phylloxera caryævenæ Fitch, with the exception that the hyperplasia extends below the leaf, while in the phylloxera gall it is developed on the upper side. The writer has observed orange colored larvæ in the aphid galls, but they were not definitely determined to be itonid.

Since this type of gall has not since been reported as definitely caused by itonid larvæ, it is barely possible that Osten Sacken described the empty phylloxera gall above mentioned containing inquilinous itonid larvæ. The writer found many of these galls deserted by the aphids in the middle of July and Pergande states that the aphid nymphs begin to leave the galls in July. At this time, these galls are a “pale yellow” color as described for the “cynipsea” gall. The writer’s observations were made in southern Ohio, while Osten Sacken’s were made in the vicinity of Washington, D. C.

Osten Sacken, Lowe’s Monogr. Dipt. N. Am. Pt. 1. p. 193. 1862.

5. Cecidomyia sp.

Leaf, under side, double chambered conic or depressed ([Fig. 5a]) gall. The latter condition is perhaps the more usual. In these forms, the conic tip is sunken in the central fovea, the gall only measuring from 1½-2 mm. vertical diameter. The conic forms are as though the tip was pulled out destroying the fovea. These often measure 5 mm. in height. The width of the galls varies from 3-5 mm. Very light green, or when older yellow to red, surface roughened with low tubercles as seen with lens. Inner chamber sub-conic with short mucronate tip. Walls of both chambers thin and smooth, outer wall slightly sticky. Base of gall flat, arising from a definite pedicel, resting in a cup-like depression, which is formed in a definite hyperplasia intercalated in the leaf. Above, this hyperplasia is evident as a raised circular area, 2½ mm. diameter, in the center of which is a minute light colored papilla.

Rather common on H. alba. Collected in Hocking and Athens counties, Ohio.

This double-chambered gall cannot be Caryomyia inanis Felt, for it is neither “globose and small.” The author describes elsewhere a specimen which fits that description and is very probably produced by the cecidozoon just mentioned. Absolute certainty, it must be remembered, can only be obtained by checking the reared adult insects with the original descriptions.

Sears described this gall from Cedar Point, Ohio, under the name C. inanis.

Sears, Ohio Nat. 15:380, pl. 18, Fig. 18. 1914.

6. Caryomyia inanis Felt.

“Globose, thin-walled with a false chamber at the apex. Dia. 2-3 mm.” Felt.

In my material, the false chamber is large, occupying more than half of the gall. The gall is slightly balloon-shape, 2½ mm. high. Surface perfectly smooth. Collected, Hocking County, Ohio, on H. ovata.

Sears in his “Insect Galls of Cedar Point (Ohio) and Vicinity,” described my number 5 under this species.

7. Cecidomyia sp. Cecidium nov.

On leaf, under side, elongate-conic constricted somewhat at base so as to resemble a miniature lamp chimney. Arises from saucer-like base. 5 mm. in length. Smooth, greenish-yellow to brown. Two chambered, the larval chamber at the proximal end, sub-spherical with a dia. about ⅓ the length of the gall. The distal false chamber large, the walls becoming thin apically. The partition separating the chambers is firm with a minute perforation at its center. Surface of leaf opposite gall not raised.

Collected in Hocking County, Ohio, on H. glabra, July.

Type specimens unaccountably missing. The description is nevertheless presented inasmuch as both it and the drawing were made from fresh material in the field.

8. Cecidomyia sp. Cecidium nov.

On leaf, under side, a gall similar to 7, perhaps a variety of it, though its prominent and constant differences would indicate a distinct species. Conic with rounded base and truncate tip, 4-6 mm. high, 3-4 mm. broad in widest part. The wall at the tip thin, splitting into a fimbriate condition. Attached by a minute central pedicel, no trace of a saucer-shaped structure developing around the base. Galls greenish to red and purple tinted. Uniformly being covered with sparsely distributed short hairs. Interiorly two chambered, the larval chamber proximal and occupying nearly one-half of the gall. Walls including the partition comparatively thin. Surface of leaf opposite gall slightly raised with reddish tint.

Collected in Athens County, Ohio, on H. alba, August.

Type specimens at Ohio State University.

9. Cecidomyia sp. Cecidium nov.

On leaf, under side, elongate conic, asymmetric, the axis lying horizontal or parallel with the leaf blade plane. The tip is invariably strongly recurved upward and backward. The side of the proximal part of the gall lying against the leaf is flattened and rests close against the leaf and vein; the galls always spring from the side of a vein. Size variable from 2 mm. in length to 4 mm. this measurement distally not being made to the tip but merely to that part of the recurved terminal portion, farthest from the base. The larger specimens measure 1½-2 mm. in width at the proximal end. Light green to nearly white, or sometimes roseate tinged. Very smooth. Walls thin distally thickening toward the basal end.

Not uncommon on H. alba in Hocking County, Ohio, July.

Type specimens at Ohio State University.

A gall, somewhat similar and probably a variety of the above was collected on H. glabra, ([Fig. 9a.])

Cylindric-conic, sharply bent over against the leaf, attenuate distal part short, not recurved, 3½ mm. long. Smooth, white like ivory. Wall rather thick, hard. Base of gall in shallow saucer-like depression against the vein. Interiorly the distal end is choked with coarse trichomes.

10. Cecidomyia sp. Cecidium nov.

Leaf, under side, distal ⅔ of gall dome-shaped with 3-many triangular sides, the flaring base resting on the proximal, constricted or saucer-shaped ⅓; 2-3 mm. high, 3-4 mm. wide. Tip attenuate, not sharp pointed, however. Light green to yellowish green, the tip darker, reddish to black. Surface smooth under lens. Larval chamber spherical, surrounded by sclerenchmya layer. This gall is very distinctive no other forms having the peculiar angular structure which it possesses. Not abundant.

Collected at Gypsum, Ohio, August, on H. microcarpa.

Type specimens at Ohio State University.

11. Cecidomyia sp. Cecidium nov.

On leaf, under side, rather large conic gall, whose distal ½-⅓ constitutes a very slender apical process. Through this passes the fine canal leading to the depressed, sub-globular chamber in the proximal part of the gall. The galls are either erect or more generally tilted to one side, always arising from one of the larger veins. 5-8 mm. long, 2½-3½ mm. wide at base. Outline of the flaring sessile base generally angular. Attenuate distal portion turning dark early. Light greenish yellow to brown when old. Smooth. Walls of chamber thick. A slender probable variety of this is figured in 11a, pl. I.

Collected in Hocking County, Ohio, on H. alba. July.

Type specimens at Ohio State University.

12. Caryomyia caryæcola O. S.

On leaf, under side, large galls with globular basal part extending into a point distally. Shape suggests that of a Prince Rupert’s drop. 4-7 mm. long. Surface very smooth, greenish to reddish tinged. Some show a definite blue color over the attenuate apical end. Walls of medium thickness, very firm. Somewhat similar to C. sanguinolenta O. S. but differs from that gall in its larger size and much more attenuate distal end. Common on different hickories.

13. Caryomyia sanguinolenta O. S.

On leaf, beneath, stoutly conical, varying in size from 1½ mm. to 4 mm. high. Tip erect or often bent to one side. Smooth, green to purplish-red and finally a brown when old. Attached to smaller veins by short pedicel, hidden from view, however, by the rounded base of the gall. Walls medium in thickness, possessing the rather soft texture of charcoal when dry; brown in color.

This form is often found in enormous numbers on certain trees, bringing about early disintegration of the affected leaves. The lower leaves are more heavily infested due to the fact that the insects are apt to reach these first in their flight from the ground in the spring.

14. Cecidomyia sp. Cecidium nov.

Leaf, under side, distal half conic-attenuate from the bulbous or sub-globular proximal half. Covered with long, coarse trichomes, the longest being half the length of the gall. Trichomes brown. Tip of gall generally darker than rest. 3-4 mm. high, 2-3 mm. wide. Cavity sub-spherical somewhat depressed at right angles to axis of gall. Walls relatively thick, especially the proximal part. Apical canal evident in median longitudinal section. Gall attached by short and broad pillar of tissue extending from the leaf into the fleshy base.

Gypsum, Ohio, August, on H. ovata.

Type specimens at Ohio State University.

15. Cecidomyia sp. Cecidium nov.

On leaf, under side, small, conic galls, generally found in pairs closely appressed to each other but not confluent. Distal attenuate ⅓ rather sharply constricted from the sub-globular ⅔ of the gall and generally turned to one side. 2 mm. high, 1½-2 mm. broad at base. Yellowish in color, definitely and constantly pubescent. Interiorly the lining of the sub-globular larval chamber is deep blue-black in color. Walls of medium thickness. Comparatively large region of the base involved in the attachment of the gall.

Collected in Hocking County, Ohio, on H. alba, July.

Type specimens at Ohio State University.

16. Cecidomyia sp.

On leaf, under side, greatly depressed with central, prominent nipple, 3-5 mm. dia. 1½-2½ mm. thick (vertical dia.) not including nipple. Light green, smooth. Firm fleshy with central sub-spherical larval chamber whose wall is differentiated from the surrounding tissue. Apical canal through nipple evident. This gall first reported and illustrated by Thompson.

Thompson, Illus. Cat. Am. Ins. Galls. 1915. p. 56, pl. 13, Fig. 228.

A most interesting variant of this form is illustrated in [Fig. 16a]. If it were not for the large number of intermediate forms found, this one would easily be considered distinct. The region of the chamber surrounded by thick walls has been much reduced, so that only a circular area about the upper part of the chamber has the thick wall projecting from it. This new condition results in the formation of a definite saucer-shaped structure on the distal end of the gall. In some specimens the structure was no longer saucer-shape, but by the ingrowth of the edges it was assuming a spherical form, developing a two-chambered gall. It is natural to suspect that this may have been the mode of origin of the four-double-chambered galls described elsewhere in this paper. That, however, is entirely problematic.

17. Caryomyia periscoides Beut.

On leaf, underside, generally large, sub-globular galls. Younger ones appear like older, both often being found on same leaflet, 4-7 mm. diameter. Galls covered with a fine short yellowish to reddish pubescence, suggesting the texture of peach “bloom.” Walls very thick, firm fleshy, surrounding the central spherical cavity, pierced, however, at the distal end by the fine apical canal. Closely sessile on leaf, generally at side of principal vein. Collected on H. alba, glabra and ovata.

From Felt’s short description, Caryomyia antennata Felt, must have been taken from a similar gall.

18. Cecidomyia sp.

On leaf, under side, sub-globular (almost uniformly asymmetric in that one side projects laterally so as to present a parabolic outline, rather than a semi-circular one). A short definite nipple terminates the gall. 2-4 mm. diameter. White or light yellow to red. Walls medium in thickness, of a soft, almost fleshy consistency. Exterior surface almost uniformly minutely shagreen-roughened when observed with lens. The constricted base of the gall rests in a shallow saucer-shaped structure.

This gall was described from Connecticut in citation below on H. ovata. Rather common in Hocking County, Ohio, on H. microcarpa. July, August.

19. Cecidomyia sp. Cecidium nov.

On leaf, under side, small, smooth, spherical galls, with a peculiar tip shaped like the end of a bottle, arising abruptly from the globular gall, 2-2½ mm. diameter. The gall reminds one of a miniature bomb. Green to yellowish with dark spots over the distal half. Thin-walled. Attached by a minute obconic pedicel. The pupa in these galls is suspended in the upper part of the chamber by a thread passing from each end of the body to the walls of the chamber. The galls drop from the leaves in late July. Not common.

Collected in Hocking County, Ohio, July, on H. microcarpa.

Type specimens at Ohio State University.

20. Caryomyia caryæ O. S.

On leaf, under side, sub-spherical gall with more or less prominent apical nipple. 3-3½ mm. diameter, rarely 4 mm. Light green, turning brown, smooth. In many, very definite meridian-like striations can be observed marking the wall. Wall thin, very fragile and dry. Surface of chamber smooth as though polished. Attached by conic pedicel arising from fovea in base of gall. This pedicel with its pointed end attached to the leaf is surrounded by or rests in a cup-like structure. In this respect the gall differs markedly from No. 22, which it superficially very much resembles.

[Fig. 20a] is a large specimen showing the peculiar interlocking base exceptionally well developed.

Collected from H. alba and H. ovata, July and August.

Felt, Jour. Econ. Ent. 4:456. 1911.

21. Caryomyia holotricha O. S.

On leaf, under side, large tawny, long-haired galls, distributed singly ([Fig. 21]) or massed ([Fig. 21a]) on the leaflet. When massed they form a conspicuous brown, hairy structure, suggesting a huge caterpillar. The isolated galls are sub-globular to round-conic with or without a small terminal nipple. 3-5 mm. vertical diameter, 3-5 mm. wide. Interiorly the chamber of the isolated form is depressed, this fact being associated with that of the thick distal wall. Gall chamber surrounded by definite sclerenchyma layer. Cortical tissue firm. Attached by irregular process from leaf extending into base of gall. In the massed forms, the galls are similar in structure, but are variously shaped, due to mutual pressure, ([Fig. 21b]). Compactly attached to the common central hyperplasia along the vein, which on the upper side of the leaf is a reddish irregular, low elevation. Some of these masses are as long as 5 cm., possessing a thickness of 10-15 mm.

Common on various hickories, particularly H. ovata.

A gall which may eventually prove to be a different species but which here is provisionally classed as a variety of C. holotricha, was found in numbers on the leaves of H. alba, though it is probably not restricted to this species of hickory. Instead of an apical nipple, it has an apical pit, which is choked with the characteristic brown pubescence of this type of gall. Internally a tuft of coarse brown trichomes extends inwardly from the distal side of the chamber. The chamber occupies the proximal one-half to two-thirds of the gall, the wall over it being uniformly very thick. This type of gall is constant, being collected repeatedly and examined minutely.

Based on Felt’s brief description, his Caryomyia thompsoni Felt was taken from this gall or one very similar to it.

Closely allied to the above variety is another form, with internal tuft of trichomes, in which the apical nipple is present. The layer of tissue lining the chamber appears very white, due probably to the character of the tissue beneath the superficial nutritive layer. In section the thin white chamber wall is very definitely delimited from the adjoining darker tissues. Many of these conic-sub-spheric galls were 6 mm. in width. Collected on H. glabra. Types of this and the above variety are at the Ohio State University.

22. Cecidomyia sp. Cecidium nov.

On leaf, under side, sub-globular with minute apical nipple. Tip of latter truncate with fine pore in center. 3 mm. high, 2½-3 mm. wide. Generally wider through one axis. Smooth; light greenish yellow. Interiorly a more or less prominent nipple projects inward from the distal end of the chamber, traversed by the apical pore. Toward maturity the interior wall is reddened. Gall attached by a short, cylindric pillar, extending from the leaf into the base of the globular structure. At the end of summer the galls fall from the leaf, leaving this pedicel on the leaf. Galls when found are apt to occur in large numbers, as many as 50-60 commonly being found on a single leaflet.

Collected in Hocking County, Ohio, on H. microcarpa, July.

Type specimens at Ohio State University.

23. Cecidomyia sp. Cecidium nov. (?)

Leaf, under side, depressed (door-knob-shape) closely sessile on leaf attached by a very short stout pedicel. 3-4 mm. wide, 2-2½ mm. high. Greenish to dull brown, covered with short, thin pubescence or smooth. Interiorally from both the proximal and distal sides, truncated, conic processes extend inward, meeting in the center. From the end of the upper one numerous, very coarse trichomes radiate into the gall chamber, which are white at first, turning brown. The central tissue and the walls are of a firm, fleshy character. There is commonly a more or less definite fovea, exteriorly at the distal end.

Collected in southern (Hocking County) and northern (Lake County) Ohio on H. ovata.

Thompson briefly describes and illustrates a gall similar to the above which Felt as editor called Caryomia thomsoni. The illustration, however, shows the gall not be to Felt’s C. thompsoni as he has described it, viz., “Globose, with long, erect, reddish, fuscous hairs.”

24. Cecidomyia sp. Caryomyia similis Felt (?)

On leaf, under side, large, globular, 4-5 mm. dia. Light yellow-green to brown, surface puberulent. A minute nipple terminates the gall. Walls thin. Attached by a short pillar, over which the basal part of the sphere fits like a cap. Surface of leaf not noticeably raised on side opposite the gall.

Collected on H. microcarpa in Ohio and H. glabra in Connecticut.

This gall is very close if not identical with Caryomyia similis Felt. It differs from his description in that it is not “depressed.”

25. Cecidomyia sp.

On leaf, generally on upper side, balloon-shaped gall, 3-5 mm. high, 3-4 mm. wide. Terminal nipple arising from slight apical depression. Greenish-brown or sometimes varying toward a very dark purplish tinge, its peculiar color being very constant and characteristic. The surface is dotted over with short, swollen glandular hairs. Trichomes sometimes projecting slightly from apical pore. Walls very thin. Galls attached to short, stout process of the leaf, to be seen only in median, vertical section. Surface of leaf on side opposite the gall not raised. Never numerous on leaflet. Closely related, if not identical, with C. caryae O. S. See No. 20.

Observed on H. glabra, in Hocking County, Ohio, July.

26. Caryomyia tubicola O. S.

On leaf, under side, cylindrical with rounded distal end standing erect from the cup-like base embedded in the leaf blade. 4-6 mm. high, generally very close to 5 mm. 1 mm. dia. Body of gall, yellow to brown in color, distal end reddish to brown, at length almost black. Basal cup, greenish yellow to dark purple. Cylindrical part of gall smooth as though polished. Gall attached to the cup only at its central basal part. Before the end of summer the tube-like portion breaks away with its enclosed larva. On the side of the leaf opposite the gall its position is indicated merely by a dark discoloration. Very common on different kinds of hickories.

27. Cecidomyia sp. Cecidium nov.

Leaf, under side, arising from a shallow cup-like structure. Shape of a slender horn, slightly curved, 5-7 mm. long, 1¼ mm. wide at base. Light green at base, changing to yellow, the distal ⅔ of the gall a deep brown. No demonstrable opening at the end. Walls thin. Surface smooth, under lens minute longitudinal striations evident. Very little discoloration on the upper side of the leaf to mark the location of the gall beneath. Resembles Caryomyia tubicola O. S. but is certainly a different species.

Collected in Hocking County, Ohio, July, on H. alba.

Type specimens at Ohio State University.

28. Cecidomyia sp. Cecidium nov.

On leaf, generally upper side, delicate, small, sub-cylindric galls, standing erect, 2-2½ mm. high, less than 1 mm. wide, constricted proximally to the slightly flaring base. Distal end marked off by a circular ridge, in the center of which is a rounded nipple. This latter turns dark early. Gall light green, at length turning brown. Arises from intervenal areas between the smaller veins. On the under side of the leaf the gall above is indicated by a minute dark area. Attached to leaf by minute central pedicel.

Collected in Hocking County, Ohio, on H. alba in July.

Type specimens at Ohio State University.

29. Cecidozoon (Type undetermined.) Cecidium nov.

On leaf, under side, rather large, pouch-like gall (5-6 mm. long) arising from a principal vein. Shaped like a stout gourd, it is bent over nearly recumbent against the blade of the leaf. 2-2½ mm. wide. The proximal end is sharply constricted at the minute point of attachment. The walls when collected were light brown in color, sparsely covered with short white hairs. Walls very thin and when dry brittle. Interior surface smooth. Inconspicuous on the upper side of the leaf, except for the minute pore next the vein. Two specimens from the same leaflet.

This gall differs so markedly from all the other cecidomyidous galls of the hickories, that I am not certain just where to place it. They contained no occupants of any kind.

Collected in Hocking County, Ohio, on H. glabra, July.

Type specimens at Ohio State University.

30. Cecidomyia sp. Cecidium nov.

On leaf, under side, obconic gall resting in firm collar-like base. Somewhat similar to 31, but differs in definite constant characters to make it distinct. Proximal end not rounded but definitely conic, distal broad end with prominent fovea in the center of which arises a well defined nipple. Dia. across top, 2½ mm., height from leaf surface, 2 mm. Greenish to reddish brown, smooth. No prominence or convexity of leaf surface opposite the gall, a slight discoloration only marking the position of the cecidium.

Collected in Hocking County, Ohio, on H. microcarpa, July.

Type specimens at Ohio State University.

31. Cecidomyia sp. Cecidium nov.

On leaf, under side, small, obconic galls which in development appear to burst through the epidermis, for gall is surrounded by the ragged collar-like remnant. The rounded proximal end strongly sunken in the leaf blade which is prominently convex on the opposite side. Distal end truncate with funnel-like depression leading to the rather large apical pore. This latter connects the depressed chamber within with the exterior. Distal broad end 1½ mm. wide. Gall projects from leaf surface 1-1½ mm. Smooth; light greenish-yellow in color. Walls very thick distally, very thin proximally where it is connected to the leaf at the central region. On the upper side of the leaf the low, hemispheric convexity is reddened, particularly toward the periphery. At first it was thought that this gall might be a juvenile form of H. tubicola, but later observations have shown it to grow no further in length. It is without doubt distinct and new.

32. Cecidomyia sp.

“Leaf-gall on under surface, having the form of a much depressed inverted cone, attached by its apex, and with the free base surrounded by a conspicuous fringe. 3-4 mm. high, 4-5 mm. in diameter. Green to light yellow-green. Huron, July 25. Quite rare and I believe hitherto unreported.” Sears.

The author has collected this interesting gall at Gypsum, Ohio, in August. Many of them measured 5 mm., not including the radiate, bract-like processes borne on the flaring rim of the gall. The galls bear an evanescent thin disk of tissue on the distal, central region, which is clear brown in color and bears erect scattered trichomes. The underlying surface of the gall or the outer convex part is perfectly smooth. The origin of the apical, brown disk is problematical; from the material at hand it appeared as if the rim of the gall had developed by pushing out beneath the original apical tissue. After the disk falls, only a minute dark spot marks the apex of the gall. The surface of the under half of the gall, below the flaring, lacerate rim, is more or less pubescent.

Chamber comparatively large; walls thin.

This very striking gall has thus far only been collected by Mr. Sears and myself, both times in northern Ohio and occurring on H. ovata.

Some specimens, all occurring on the same leaf varied in that they were not so depressed (almost sub-hemispheric) and had the rim strongly inturned against the very convex distal half of the gall.

Sears, Ohio Nat. 15:380. 1914.

33. Cecidomyia? sp.

On leaf, blister-like, irregularly circular in outline, 2½-3½ mm. diameter, ½ mm. thick. Extends above and below about equally. Sometimes a slight central nipple is formed below. Greenish to brownish with discolored margin.

Collected in Vinton County, Ohio, on H. cordiformis.

Probably same as Felt’s “Leaf blister gall, irregular, dull greenish or black margined with small nipple. Diameter 3mm.”

This type of gall is so different from all the other cecidomyid forms that it is doubtful if it is a member of that group. It may possibly be an immature or small Phylloxera gall. The writer found white larvæ within his specimens, but was unable to determine them as cecidomyid larvæ. This gall is thus introduced here, provisionally.

Felt, Jour. Econ. Ent. 4:456. 1911.