Dryophanta erinacei (Mayr)

The Oak Hedgehog Gall is rounded or oblong, with the surface finely netted with fissures, and more or less densely covered with spines. It varies in length from 10-15 mm, and occurs on both sides of the White Oak leaf. The point of attachment is generally on the midrib (Fig. I, Pl I), though it is often found on the lateral veins. When young it is yellowish green, but in autumn it becomes yellowish brown, much lighter in color than the tinting of the leaf. The gall first appears late in June, and reaches full development about the third week in August. It is widely distributed, having been reported from New England, North Carolina, Iowa, Illinois, Indiana, Kansas, Michigan, Ohio, Virginia, Canada, and probably Florida and Colorado.

A longitudinal section through the gall shows that it contains several chambers varying from two to eight in number. These I have named according to their location. First to be noted are the central cavities, (Fig. 2a, PI. I), which measure 2 mm x 3 mm and are located in the central portion of the growth. These are occupied by Dryophanta erinacei and the parasites. Second, there are the lateral cavities, (Fig. 2b, Pl I), situated at the side and base of the growth and measuring 13 mm x 2 mm. These are occupied by inquilines. Lastly, there are to be found the peripheral cavities, (Fig. 8a, Pl II), located on the coriaceous portion of the gall, and covered with the basal layer of spines. These are 1 mm in size, and are likewise occupied by inquilines.

The gall was first described by Walsh in 1864 under the name Cynips q. erinacei. When Mayr in 1881 established the genus Acraspis he included the insect causing this gall, which therefore was known as Acraspis erinacei. The first description of the insect appeared in a paper by Beutenmiiller '09, entitled "Species of Biorhiza, Philonix, and their allied Genera, and their Galls," in which he places it in the genus Philonix. As will be shown later in this discussion, the insect belongs to the genus Dryophanta, and should be known therefore as Dryophanta erinacei (Mayr).

The Life-History of Dryophanta Erinacei.

In the open the [sexgen] adults did not emerge until the twenty-ninth of May, and continued to oviposit from that time until the fifth of June. The egg is oval, provided with a pedicel 750m. in length. It is always placed in the fibro-vascular bundles, and at an angle of about 80° to the axis of the leaf.

On the twenty-fifth of June the first evidences of gall-formation appeared on the leaf-veins, the hypertrophied tissue pushing through the slightly ruptured epidermis. In galls gathered on the first and second of July, larva were found measuring 375 um. During the summer, molts were observed after which the larva measured 750 um, 1.25 mm, 1.75 mm, 2.25 mm, respectively, thus showing five stages during the life-history. Fig. 19, PI. Ill, shows a larva 1.75 mm, obtained about the middle of August. From this time, the thorax does not show a great increase in size,, but the abdomen loses its reflexed character, becomes globose,, and increases in size until pupation. The first pupa was obtained on the fifth of September, but the adults did not emerge until the fifth of November. Fig. 5, PI. I, shows a pupa of the agamic form.

The agamic form of Dryophanta erinacei emerges from the oak hedgehog gall about the fifth of November.

The insect makes its way to the leaf and flower buds of the white oak, where oviposition takes place. On the tree where our observations were made, it continued to emerge and oviposit until the twenty-first of November. The insects are most active on cold days or early in the morning. During the warm weather they are inactive and sluggish, hiding at the base of the petioles, in the crotches of the young shoots, or in the crevices of the bark. They have been taken in this vicinity on rare occasions in early December, but usually they succumb to the first heavy frosts at the close of November.

Acraspis erinacei agamic

Quercus alba
Leaf galls, detachable
Hedgehog Gall. Ellipsoid, to 13 mm in dia, tuberculate with red hairs, 3-5 celled, in fall.

[Photo caption]

187. On Q alba. The Hedgehog Gall. Adults emerge in Oct (IO), in Nov (MI), in Dec (NY). In the Chicago area on Nov 1 leaves were still on trees and the adults had only to crawl to the buds nearby where they were seen to oviposit during an early flurry of snow.

Andricus fulvicollis form erinacei [Kinsey reverses the synonymy of fulvicollis and erinacei in later work]

Philonix fulvicollis
Cynips quercus erinacei
Teras fulvicollis
Cynips fulvicollis
Acraspis erinacei
Biorhiza fulvicollis
Biorrhiza fulvicollis
Acraspis quercus-erinacei

Galls. — Oval leaf-galls (Fig. 34), densely covered with fine spines, reddish purple. The galls are globular or more often oval, 10X14 mm., more or less, the surface light yellowish, closely set with small, raised points, each tipped with a slender, thread like, flexuous spine 2 or 3 mm. long, yellowish, reddish purple, or blackish in color. Within, the tissue is compact-granular, the larval cells usually two or three (two to eight), each measuring about 1. 5X2.0 mm., the cells distinct but inseparable. Attached by a single point to a main-vein, on the upper or under surfaces of leaves of Quercus alba.

Range: Ontario, MA, CT, NY, NJ, PA, VA, NC, FL, OH, IN, IL, MI, IO, KS, OK, CO [Kinsey places question marks by FL and CO indicating some doubt about these records]

Beutenmuller is authority for the identity of erinacei and fulvicollis. This gall appears in late June, becoming mature about the last of August, staying on the trees into October. The insects emerge from November 5 to 21. or even in early December, often when the weather is very cold, and snow is on the ground. The insect oviposits in the young buds of the oak trees. Fuller details of the habits of this species are given in Triggerson’s paper.

Cynips pezomachoides variety erinacei
agamic form erinacei

[Kinsey reduces Acraspis erinacei to a variety of Acraspis pezomachoides, and var erinacei is only one of many varieties that may take spiny forms. Thus in Kinsey's formulation of the group, pezomachoides and erinacei are not distinct species, and spines are not a sufficient character to distinguish their galls. This differs from Weld's description. It isn't clear which will ultimately be accurate.]

Quercus erinaceus
Acraspis erinacei
Cynips quercus erinaceus
Acraspis erinaceae
Cynips pisum (gall only)
Philonix erinacei
Acraspis quercus-erinacei
Dryophanta erinacei
Philonyx erinacei
Philonix fulvicollis err syn
Andricus fulvicollis erinacei err syn

GALL.— -Known from both the naked and spiny forms; on leaves of Quercus alba. Figures 4, 312-315, 328, 331.

RANGE. — Ontario: Toronto (acc. Cosens 1912; also Brodie in U.S. Nat. Mus.) . Maine: Kezar Falls (Mrs. D. Tenney in Kinsey coll.). New Hampshire: Exeter, Alton Bay, and Dover (Mrs. D. Tenney in Kinsey coll.). Stratham (gall, Mrs. D. Tenney in Kinsey coll.). Massachusetts: Forest Hills (Kinsey coll.). Framingham (C. A. Frost in Kinsey coll.). Springfield (galls acc. Stebbins 1910). Connecticut: Waterbury (Bassett in Kinsey coll.). Stamford (Bartlett acc. Felt 1921: 73). New York: Buffalo (Moeser acc. Gillette 1896). Waterport and Ithaca (galls, acc. Weld 1926). Syracuse (galls, Crosby acc. Weld 1926). Penn Yan and Albany (acc. Weld 1926). New York City (gall in Amer. Mus. and Kinsey coll.). Oakwood (W. T. Davis in Kinsey coll.). New Jersey: Ft. Lee and New Brunswick (Beutenmiiller in Amer. Mus. and Kinsey coll.). Ft. Lee (gall, Beutenmiiller in Amer. Mus.). Pennsylvania: Washingtonville (gall, E. C. Zeliff in Kinsey coll.). Meadville (Roy Wilson in Kinsey coll.). D.C.: Washington (gall, acc. Weld 1926). Maryland: Oakland (inch hybrids with pezomachoides ; Kinsey coll.) . Virginia: Bluemont (galls, acc. Weld 1926). Big Stone Gap (inch hybrids with pezomachoides; Kinsey coll.). Blue Ridge Mountains near Natural Bridge Station, and Natural Bridge (galls, Kinsey coll.). West Virginia: Beckley, Wolf Summit, and Parkersburg (Kinsey coll.). Kentucky: Lebanon, Livingston, Cleveland, Whitley, and Pineville (inch hybrids; Kinsey coll.). Ohio: Elyria (acc. Weld 1926). Painesville (thru C. V. Riley, in U.S. Nat. Mus.) . Wooster and Columbus (in U.S. Nat. Mus.) . Rock- port? (Bassett coll., Beutenmuller types). Chillicothe (Kinsey coll.). Indiana: Mongo (inch hybrids with wheeleri, Kinsey coll.) . Ft. Wayne (C. M. Kinsey coll.). Crawfordsville (gall, E. C. Stout in Kin- sey coll.). Ladoga (galls, H. Lee in Kinsey coll.). Porter (galls, acc. Weld 1926). Roachdale (G. Blaydes in Kinsey coll.). Putnam County (galls, acc. Cook 1902). Belmont (F. Payne in Kinsey coll.). Crothers- ville (galls, C. C. Deam in Kinsey coll.). Palmyra (galls, C. C. Beam in Kinsey coll.). Memphis and Charlestown (E. W. Spieth in Kinsey coll.) . Greensburg and Olean in Ripley County (galls, G. F. Hyatt in Kinsey coll.). Versailles (G. F. Hyatt in Kinsey coll.). North Webster, Rochester, Huntington, and Mitchell (galls, Kinsey coil.). Bloomington, 6 miles east of Bloomington, 10 miles southeast of Bloomington, Nash- ville, Spencer, Bedford, and Clinton (Kinsey coll.). Illinois: Winnetka, Evanston, Glen Ellyn, Moline (galls, acc. Weld 1926). Glencoe and Willow Springs (bisex. form, acc. Weld 1926). Ravinia (galls, Weld in Mus. Comp. Zool.). Urbana (galls, A. E. Miller in Kinsey coll.). Olney, West Union, and Pana (Kinsey coll.). Greenup (Kinsey coll.) . Michigan: Agricultural College (acc. Gillette 1889). Maple Rap- ids (E. S. Anderson in Kinsey coll.). 11 miles north of Lansing, and Mount Pleasant (A. D. Holloway in Kinsey coll.). West Branch, Big Rapids, Bay City, Grayling, Martin, Tekonsha, Three Rivers, and Owosso (Kinsey coll.). Wisconsin: Green Lake (galls, W. Scott in Kinsey coll.). Minnesota: Robbinsdale (galls, Ruggles acc. Felt 1921). Iowa: Ames (Gillette in U.S. Nat. Mus.). Kansas: no locality (Bridewell 1899). Riley County (Marlatt in 111. Lab.). Missouri: Barnhart (E. S. Anderson in Kinsey coll.). St. Louis (E. S. Anderson in Kinsey coll.; also acc. Weld 1926). Kimmswick (galls, acc. Weld 1926). Imperial (galls, E. S. Anderson in Kinsey coll.). Edgar Springs (galls, R. Voris in Kinsey coll.). Allenton (Let- terman acc. Packard 1890: 113; also E. S. Anderson in Kinsey coll.). Probably confined to Q. alba in the northeastern quarter of the United States and southern Canada, from Maine and Minnesota to Maryland and central Missouri, excluding the Coastal Plain areas; further south in the mountains to southwestern Virginia. Figure 68.

INQUILINE. — Synergus erinacei Gillette (acc. Gillette 1896). PARASITES. — Callimome brodiei (Ashmead) (acc. Ashmead 1887). Eurytoma auriceps Walsh (acc. Walsh 1870). E. studiosa Say (acc. Walsh 1870). Decatoma querci-lanae dorsalis (Fitch) (= D. simplicistigma Walsh; acc. Walsh 1870). D. flava Ashmead (acc. Triggerson 1914). D. varians Walsh (acc. Triggerson 1914). Ormyrus ventricosus Ashmead (acc. Triggerson 1914). Syntomaspis sp. (acc. Triggerson 1914). Tetrastichus sp. (acc. Triggerson 1914). This is a very common gall thruout the northeastern quarter of the United States and southernmost Canada, wherever the white oak, Q. alba, is found, except as this variety is replaced on the Atlantic Coastal Plain by variety pezomachoides and further north and in the Appalachians by variety wheeleri or hybrids of wheeleri. Buetenmiiller’s suggestion that this in- sect ranges “probably South to Florida” does not accord with our recent collections in the Southeast. The Osten Sacken (1873) and Ashmead (1890) records of erinacei in Colorado apply to variety cincturata. Erinacei is strictly confined to Quercus alba. Ashmead’s record (1885) of Q. montana as the host must be based on a mis-determination if it is not a lapsus, for the present species abandoned the group of oaks to which montana belongs when it separated from the stock of Cynips gemmula t. Cook’s repeated record (1905 and 1910) of the red oak, Q. rubra, as host of erinacei is a curious error, especially since the figure with the 1905 publication shows a typical Q. alba leaf. The occurrence of a true Cynips gall on any tree of the black oak group is inconceivable to one who has critically observed the host distribution of cynipid genera ill general. The type material of erinacei, from north-central Ohio, rep- resents an insect with a dark rufous head which is prominently marked with black on the mid-line, with antennae which are rufous only on the first two segments, a dark rufous mesono- tum, and a piceous black abdomen which is dark rufous ba- sally. This combination of characters is represented by insects in our collections from nearly one hundred localities scattered all the way from southern Maine and Minnesota to south- western Virginia and Missouri, but in practically all of these localities such insects have been obtained from both naked and spiny forms of the gall, and from every conceivable inter- mediate type of gall. The extreme variation of the gall is matched, moreover, by the variation of the insects in every large series which we have from localities representing the wide range of erinacei . The significance of this variation is elucidated by the occurrence of true wheeleri as one extreme of these variable series and (in most places) of derivatus as the other extreme of each series. Usually the wheeleri and de- rivatus individuals are few in comparison to the intermediates, but from Meadville, in the northwestern corner of Pennsyl- vania, we have 107 insects of which 41 per cent show distinct wheeleri influence, 37 per cent derivatus practically identical with the Alabama and Georgia material of that variety, and 21 per cent good erinacei. This series, like all the others, shows every gradation from wheeleri to derivatus, and the types called erinacei are matched by individuals near the mean favor inbreeding of the hybrids, have developed more uni- form populations than a mulatto people of more immediate origin would show. The typical gall of wheeleri is spiny; the gall of pure derivatus is always smooth and naked. The occurrence of typical spiny and naked galls in the erinacei population is to be explained as the segregation of the parental types from the heterozygotic individuals. The occurrence of intermediate types of galls is what we should expect if the gall producing capacities of the insect are controlled by multiple factors in heredity. On the other hand, in the eastern extension of the range of erinacei, at least in northern New England and again in Virginia, erinacei comes into contact with variety pezo- machoides and probably interbreeds with it. It is even pos- sible that what we are still calling erinacei is a wheeleri x pezomachoides cross in these localities. Pezomachoides and derivatus are so similar that I cannot distinguish between their influence in a series of hybrid insects, but there is a notable difference in the galls from these two hybridizations. Wher- ever erinacei comes into contact with pezomachoides, almost all of the galls are as naked as those of pezomachoides. There are not even as many of the spiny galls in such parts of the country as we should expect to segregate from any sort of hybridization ; and it is possible that there are hereditary or environmental factors which select in favor of the pezo- machoides type of gall in such localities. Histologic studies of both the naked and spiny forms of the galls of erinacei have been made by Cook and by Cosens, both of whom are quoted in the general discussion introducing this species in the present paper. The abundance and the conspicuous nature of the spiny galls of erinacei, together with the realization that the agamic, short-winged, mid-winter female was probably followed by a bisexual, spring generation, has resulted in the accumulation of considerable data on the life history of the insect. On the basis of laboratory and field observations of insects from spiny galls of this variety, Triggerson in 1914 reported, from the Entomological Laboratories of Cornell University, the alter- nate generation of this insect in one of the most detailed studies that we have of the life history of any American cynipid. The young galls of the agamic form appear late in June (June 25 acc. Triggerson, June 28 at Toronto acc. Brodie coll.), reaching full development in August (August 17 in northern Indiana in 1927) or early September (mid-September in southern Indiana). When the hypertrophied tissue first pushes thru the slightly ruptured epidermis of the leaf, the embryos, according to Triggerson, “measured 125^.-130^. In galls gathered on the first and second of July, larva were found measuring 374^. These were similar to the young larva which give rise to the sexual form, having a slightly depressed head, sharp pointed mandibles, broad, prominent thorax, and pointed, reflexed abdomen. During the summer, molts were observed after which the larva measured 500 750 ^., 1% mm., 1% mm., 2% mm., respectively, thus show- ing five stages during the life-history. . . .” From about the middle of August “the thorax does not show a great in- crease in size, but the abdomen loses its reflexed character, becomes globose, and increases in size until pupation.” Trig- gerson obtained the first pupae on the 5th of September. Weld found pupae on September 8 (1906), near Chicago. The galls fall with the leaves to the ground late in September or October, or some of them remain with the leaves on the trees. Transformation probably occurs soon after pupation, but emergence of the adult does not ordinarily occur until some time after that. For breeding purposes, the galls are best left on the trees until just before the adults are due to emerge. Our records for emergence range from early in October to early in January, with the bulk of the adults coming out in November. Actual dates from published records, Museum col- lections, and my own breedings are October 3, 7, 10, and 31 ; November 1, 5, 7, 12, 13, 15, 16, 18, 20, 22, 26, and 27; De- cember 1, 4, 5, 8, 10, 12, 14, 16, 17, 20, 21, 22, 23, 25, and 28; and January 1 and 3. In spite of these widely distributed dates, most of the emergence occurs late in November and early in December. I have not been able to discover any correlation in these records between the latitude of the locality and the time of emergence of this insect. Triggerson’s designation of November 5 to 21 and rarely in early December for the emergence of erinacei is evidently based on a single season’s observations in a single locality. The emerged insects, according to Triggerson, “are most active on cold days or early in the morning. During the warm weather they are inactive and sluggish, hiding at the base of the petioles, in the crotches of the young shoots, or in the crevices of the bark.” The same observer adds that these insects usually succumb to the first heavy frosts, but Weld records the wasps emerging and ovipositing on a cool day when scattered flakes of snow were flying, and in my own abundant observations I have found many of the insects emerg- ing and active at temperatures below freezing. Oviposition is in the leaf or flower buds of the white oak. The behavior is described by Triggerson as follows: “The insect clasps the apical portion of the bud with the second pair of legs .... and pressing alternately with the first and third pair produces a teetering motion which forces the ovipositor into the buds. The long ovipositor lifts the apical edge of the outer scale, and is gradually pressed down along the edge of succeeding scales, and finally thrust into the region of the young leaf and flower. Then there is a sudden jerk of the body which curves the distal end of the ovipositor, turning the openings against the concave face of the innermost scale. The insect now retains a motionless attitude for almost four minutes, during which the egg is deposited. The ovipositor is then withdrawn, the passage being filled with a waxy sub- stance for the protection of the egg. This waxy secretion is doubtless from the accessory glands of the reproductive sys- tem, and is homologous with the secretions with which Cory - dalis cornuta, certain of the Lepidoptera, as the Apple Tent- Caterpillar, the Tussock-moths, and many other insects cover their eggs. “The egg ... is an oval body 400^. x 225^. provided with a pedicel which is 1 mm. in length. It is attached by this pedicel to the upper brown portion of the scale, falling either against the green portion of the scale ... or being held among the young leaves or flowers, in which position it remains during the winter. It is worthy of emphasis that this pedicel does not constitute the apical pole of the egg since the larva emerges from the opposite pole, and as already indicated it serves as an appendage for attaching the egg to the bud scale.” The galls of the succeeding, bisexual generation develop early in May as minute, egg-shaped cells in the buds or at- tached to the developing leaves or flowers. The bisexual gen- eration is described in the present paper as form bicolens. Triggerson figures the spiny galls of the agamic erinacei, including longitudinal sections, reproduces photographs of the pupae and a small photograph of the agamic female ovipositing in a bud, includes drawings of the eggs with figures of the eggs in position on the bud scales, gives details of wings, some of the mouthparts and antennal segments, including the sensory pits of the terminal segments of the antennae (structures which may serve the insect in finding its host and the buds suitable for oviposition) , details of larval chaetotaxy, and histologic sections of the larvae showing especially the Mal- pigian tubules and oenocytes. There are nine species of parasitic hymenoptera recorded from these galls. Triggerson found these “primarily parasitic on . . . erinacei, and secondarily on each other.” Two- thirds of the nearly one thousand parasites that author bred were determined as Decatoma flava (Ashmead). The para- sites were observed ovipositing about the middle of June (June 10 to 14) , Decatoma flava selecting a spot on the mid-rib where the gall maker had oviposited, thrusting its ovipositor down alongside the same channel, depositing a single egg in contact with that of the cynipid, and finally sealing the opening thru which the egg had been placed. The two species of Eurytoma oviposited in the fibro-vascular bundles of the leaf, near but not in contact with the egg of the cynipid, the eggs of these parasites being layed in clusters of up to six. Quoting again from Triggerson : “When the larva of Dryo- phanta erinacei emerges from the egg, it proceeds at once to form a cavity which encloses the eggs surrounding it. In newly-forming galls the cavity is small, and the egg of the parasites is frequently found resting in the abdominal angle of the larva of Dryophanta erinacei. Here it often hatches. The larva breaks the shell near the base of the neck . . .and emerges, proceeding to attack the host in the abdominal region. If the Cynipid larva has just molted it is destroyed at once. If on the other hand, it escapes the attacks of the parasites during this period, they will live together until the next molt occurs, when the host is almost invariably killed and eaten. Only on rare occasions have the host and parasite been found living together in the same cavity until both have reached 1 mm. in length. “If two parasitic larvae of the same or different species are found in one cavity in the early stages, the stronger alone survives, for I never have observed more than one adult emerge from a single cavity.” Decatoma flava apparently has only a single brood annually, but each of the two species of Eurytoma has a brood that emerges from the young galls from July 24 to August 1, and a brood that does not emerge until the middle of the following June. “After the parasites have destroyed the host, it is ques- tionable whether they feed on the plant tissue, since the lining of the cavity they inhabit turns brown, becoming hard and brittle much earlier than is the case with the cavities occupied by Dryophanta erinacei” Of 1050 galls which this observer examined, sixty per cent [of the galls or larval cells?] were parasitized. I have found a similarly high percentage of parasitism in material from several localities, but in more than a thousand galls from Big Stone Gap, Virginia, and many hundreds of galls from each of a dozen other localities I found a parasitism which I should roughly estimate as not more than five or ten per cent. Altho I have at times published data on the percentage of parasitism of cynipid galls, I have come to believe that the conditions vary so greatly in different localities and in different seasons that it will be difficult ever to arrive at an estimate that will fairly represent the amount of parasitism normal for any species. Triggerson studied Synergus erinacei , finding it present in these galls not only as a guest but as a parasite which fed di- rectly on the larvae both of the gall maker and of the parasites. On eight occasions Triggerson fed gall maker and chalcidid larvae directly to the Synergus larvae, altho only once was he able to feed them larvae of their own species. The inquiline even mines from cavity to cavity of the polythalamous galls. It is to be questioned whether such mining is primarily in search of food or an evidence of primitive, phytophagous be- havior such as was probably the ancestral right of the Cyn- ipidae. Triggerson observed over eighty instances of such mining by this Synergus. “The average time required by Synergus erinacei to consume a larva was 1% hours.” This insect was found to have two broods each year, the larvae of the broods differing in some respects, but the observer did not record whether there is anything in this inquiline that ap- proaches the heterogeny of so many of the gall making species. Five pages of Triggerson’s paper are given to the life history of the gall maker, and another five pages to the parasites and inquilines. The remaining fourteen pages are given to an in- teresting if unconvincing discussion of the stimulus to gall production. Following a suggestion of Rossig’s (1904), Trig- gerson studied the Malpighian tubules of erinacei and con- cluded that they “secrete a fluid which stimulates the plant to produce the gall.” He summarizes his reasons for so believing as follows: A. The character of the Malpighian vessels of the sexual and agamic forms of Dryophanta erinacei — their size, cellular structure, and exceptional glandular activity. B. The character and effect of the secretion poured forth by the Malpighian vessels during gall formation. C. The ultimate decline and ceasing of marked activity of the tubules when the gall has matured. D. The increase in the size of the cells of the Malpighian vessels coincident with the development of the gall, and their decrease in size when the demand upon them is withdrawn. E. A comparison of the Malpighian vessels of Dryophanta erinacei with those of the parasites and the inquilines found in the gall, and particularly the lack of any abnormal secreting activity in the latter. F. A study of the Malpighian vessels of Holcaspis globulus, and Dryophanta polita, both of which correspond in their action, develop- ment, and degeneration to those of Dryophanta erinacei. G. A comparative study of the Malpighian vessels of Dryophanta erinacei with those of Nematus pomum, Trypeta solidaginis, and Ceci- domyia strobiloides shows that all the latter, though gall producers, possess tubules of normal type, which do not pour forth an abundant secretion during gall development, nor when in contact with foreign substances. H. The study of the Malpighian vessels of species of Braconids and Ichneumons, shows tubules with cells not larger than those of the Chalcids and inquilines. The mode of degeneration however, appears similar to that found in Dryophanta erinacei. While I do not believe that Triggerson’s data fully support the conclusion on the gall making stimulus, this paper should be carefully weighed by some future investigator whose studies will include a wider selection of gall wasps. Convincing proof of the source of the stimulus must include the artificial pro- duction of a specialized gall, or at least the control of gall production by the control of the suspected gall producing struc- tures of the larval cynipid. Further discussion of this ques-tion is unnecessary in the present taxonomic study. Trigger- son's original paper should be consulted for details that we have not quoted here.

[Kinsey lists these other varieties also producing spiny galls on Q alba:

ozark, known from galls ranging from naked to spiny on Quercus alba in OH, WV, IN, IL, KY, MO, AR

wheeleri, known from galls ranging from naked to spiny on Quercus alba in NH, MA, PA, OH, MD, WV, MI, IN, IL, MO, VA, KY, TN, NC, GA

advena, known from naked to spiny galls on Quercus alba in KY, TN, NC, SC, GA]