Nematus quercicola

Eupontania salicispisum

Pontania pisum

Pontania salicispisum

Nematus salicispisum

Tenthredinidae

Euura

Salix discolor

Colorado

Connecticut

Delaware

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Indiana

Iowa

Kentucky

Maine

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Massachusetts

Michigan

Minnesota

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Vermont

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Northwest Territories

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Quebec

Saskatchewan

Plant Galls and Gall Makers

Types and biological notes of the eastern North American sawflies of Pontania Costa and Phyllocolpa Benson (Hymenoptera: Tenthredinidae) described by Marlatt, Dyar, and Rohwer

Revision of the Nematina of North America, a Sub-family of Leaf-feeding Hymenoptera of the Family Tenthredinidae

Key to American Insect Galls

Euura salicispisum

S pisum, n. sp.

On Salix discolor

A subspherical, pea-like, hollow, pale yellowish-green gall, always growing on the under side of the leaf. and almost always from one of the side-veins, very rarely (1 specimen) from the midrib, and attached to the leaf by only a minute portion of its surface, .18 — .28 inch in diameter, and a few, which were probably immature or abortive, only .08 inch in diameter. Almost invariably there is but one gall to one leaf: but on 4 leaves there were two, and on 2 leaves three of them, and occasionally two are confluent. The surface of the gall is without pubescence, in some smooth and even, in others a little shrivelled, generally studded in the medium-sized ones with 4 — 12 small, robustly conical nipples, which in the larger ones have hurst into a scabrous brown scar. Only in 3 out of 62 galls was there any rosy cheek, as in S. pomum. The point of attachment is marked on the upper side of the leaf by a brown sub-hemispherical depression about .04 inch in diameter. Abundant but local. Described Aug. 25 from 62 freshly-gathered galls. At the time the 1st part of this Paper was published I was unacquainted with this gall, which accounts for the irregularity in the numbering, (21 bis.) 

On the same bush with the above there occurred 13 galls, mostly unbored, so identical in appearance with S. pomum that I did not think it worth while to attempt to breed from them. On Oct. 14, out of another lot of S. pisum on another bush of S. discolor, I found that about one-fourth to one-fifth had a slightly rosy cheek. On this bush also I met with 4 S. pomum in company with S. pisum. but all empty and bored, but whether bored by the Gall-maker or by the inquilinous Anthonomus sycophamta. n. sp. (Coleoptera) is uncertain. In both the above two cases a few S. discolor bushes were growing in the midst of very large numbers of S. cordata [eriocephala], the species on which S. pomum is normally found. This gall is evidently allied to those produced by the European Nematus intercus and N. gallarum, which are described as "globose, spongy, pedunculated galls along the mainrib of the leaf;" but it differs in growing, not exclusively from the mainrib, but indiscriminately from any of the veins. Distinct from S. pomum by its being peduncled not sessile, and by its smaller size and the general absence of a rosy cheek, and from S. desmodioides by its short peduncle and by its very different shape. 

On the Insects, Coleopterous, Hymenopterous & Dipterous: Inhabiting the Galls of Certain Species of Willow. Pt 2nd and last

Pontania pisum

Nematus salicis pisum
Nematus quercicola
Nematus pisum

"Gall. — The gall made by it is found on Salix discolor. A subspherical, pea-like, hollow, pale yellowish-green gall, always growing on the underside of the leaf and almost always from one of the side veins (in one case from the midrib), and attached to the leaf by only a minute portion of its surface; 0.18 to 0.28 inch in diameter, and a few, immature, only 0.08 inch in diameter. Almost invariably there is but one gall to the leaf, but on four leaves there were two, and occasionally two are confluent. Surface in some smooth and even, without pubescence; in others a little shriveled, generally studded in the medium-sized ones with four to twelve small, robustly conical nipples, which in the larger ones have burst into a scabrous blown scar. Only in three out of sixty-two was there any rosy cheek, as in S. pomum. The point of attachment is marked on the upper side of the leaf by a brown subhemispherical depression.

Range: IL, NY

Pontania pisum Walsh

on S. discolor Muhl.

"On Salix discolor. A subspherical, pea-like, hollow, pale yellowish- green gall, always growing on the under side of the leaf and almost always from one of the side veins (in one case from the midrib), and attached to the leaf by only a minute portion of its surface; 0.18 to 0.28 inch in diameter and a few miniature, only 0.08 inch in diameter. Almost invariably there is but one gall to the leaf, but on four leaves there were two, and occasionally two are confluent. Surface in some smooth and even without pubescence; in others a little shriveled, generally studded in the medium-sized ones with four to twelve small, robustly conical nipples, which in the larger ones have burst into a scabrous brown scar. Only in three out of sixty-two was there any rosy cheek as in P. pomum. The point of attachment is marked on the upper side of the leaf by a brown sub-hemispherical depression." — Walsh .

Walsh is incorrect in supposing that this gall originates from a midrib or vein. A section shows that it is clearly a product of the mesophyll and is attached to that part of the leaf. The side vein, near which it is always placed, is cut by the ovipositor, however, and vascular strands pass out from it into the gall body. 

The mature gall consists of a peripheral layer of thin-walled cells, irregular in outline surrounding a central cavity (Fig. 81). This tissue is clearly derived from the mesophyll and epidermis of the leaf, but a stage was not secured young enough to show the relative amounts produced from each. The epidermis bears numerous lenticels, organs which Kuster mentions as occurring on the gall produced by Pontania salicis. 

At the point of attachment of the gall the blade of the leaf is strengthened by several rows of cells derived from the upper epidermis and the palisade parenchyma, as shown in Fig. 81. These cells seem to have remained unmodified in any way, since their arrangement in rows is still clear in fairly old stages of the gall. Consequently they differ very markedly from the irregularly arranged cells of the main part of the gall body.

A contribution to the morphology and biology of insect galls 

Pontania pisum

Host: Salix discolor

An almost spherical pea-like gall, with a small point of attachment to the leaf of the host. Only rarely found in the locality. 

Range: Toronto, Ontario

Reports on insects of the year, Division No. 3, Toronto District. Forty-Fifth Annual Report of the Entomological Society of Ontario, 1914

Pontania pisum

Subspherical, pealike, hollow, pale yellowish green gall on under side of leaf, usually on a side vein, diameter 5 to 7 mm. 

Pontania pisum

Salix
Leaf galls

Pea-like, pale yellowish gall, on underside of leaf, diameter .25 inch, sawfly, spring

[Listed in photos but not in text]

Hosts: Salix discolor

Eupontania salicispisum, new combination. 

Nematus salicispisum

Valid name. — Eupontania salicispisum (Walsh), new combination. 

Host. — Salix discolor: The gall is illustrated by Zinovjev and Smith (1999: fig. 1). They are small, rounded, and attached to the sideveins, with a very small scar visible from the upperside and concave below the leaf surface. 

Nematus quercicola 

Valid name. — Eupontania salicispisum (Walsh) (= Nematus quercicola Walsh). 

Notes. — Nematus quercicola was treated as a synonym of the preceding species by Marlatt (1896), or by others (e.g.. Smith 1979) as a nomen nudum because the only character mentioned by Walsh to distin- guish it from the preceding species was that "all N. s. pisum went underground to pupize" and 'N. quercicola pupized in the gall." A biological feature such as this, by formal reasons, could be treated as a "character," and we should accept this name as an available one. According to Walsh, this species "cannot be distinguished from the gallmaking N. s. pisum male, female." 

Sawflies (Hymenoptera: Tenthredinidae) described by Benjamin D. Walsh, with notes on their hosts and biology