Andricus piperoides

Q rubra, CT. Summer second year before Spring. Red oaks, MA. Fuzzy, globular.

Dryocosmus piperoides

Similar in size and shape [to Andricus dimorphus] but red in color, in an elongated less compact cluster on upper or lower side of large leaves on thrifty shoots of Q rubra, dropping in October. Pubescent under lens. Adults emerged April-May the second spring and some hang over to emerge still later.

Callirhytis piperoides

Quercus coccinea, ilicifolia, rubra, velutina
Leaf galls, detachable
Cluster on upper or lower side, each spherical, red, pubescent, 1-4 mm. in dia. & dropping in fall.

[Photo caption]
On Q rubra. Also on Q ilicifolia, coccinea, texana [buckleyi]. Adults emerged Apr 22-May 11 the second spring and Apr 16 the third spring.

Dryocosmus piperoides

Andricus piperoides

Galls of this species were noted on the leaves of Q maxima [rubra] in IL, NY, and VA. Some specimens sent from Maine were determined by the writer as those of this species. Galls collected in IL in October contained both pupae and larvae in September and adults and larvae in November. Adults emerged April to May. The emergence is evidently distributed over at least two seasons. Beutenmueller notes that the galls were very common in the fall of 1916 and again in 1918, but none were noticed in 1917.

The species is here transferred to Dryocosmus.

Andricus piperoides

These galls are found in clusters of one to five dozen along the midrib, looking as if they had burst out from the inside of the leaf or vein. Each is smooth, spherical, attached by a small stem, 3.8 mm in diameter, monothalamous, grayish or tinged with red. They fall to the ground, where the larva completes its metamorphosis, which sometimes requires two years. Insects in second summer. Leaves of red oak Q rubra. Not rare.

Andricus piperoides

Clustered, pubescent, globular, drab or brownish red midvein galls, frequently splitting and extending along the vein 4 to 8 cm, diameter 3 to 9 mm, occur in clusters of 10 to 100 or more on a leaf, on Q rubra.

Andricus piperoides, n. sp.

Galls from one-eighth to three-eighths of an inch in diameter, in dense clusters along the mid-vein of full grown red oak leaves (Quercus rubra). They are found only on the largest leaves of the thriftiest shoots of young oaks. The clusters contain from one or two dozen galls up to a hundred or more, and extend along the vein two, three or even four inches. The vein is considerably enlarged, and is often split by the crowding of the galls as they increase in size. The blade of the leaf is often torn by the same force and the galls appear on both surfaces. When on the tree they are covered with a dense, coarse pubescence which is, in color, a dusky drab, or when exposed to the sun a brownish red. They are round except a very slight elongation at the point of attachment to the leaf. After falling to the ground they soon turn black, and after losing their pubescence they resemble quite closely small black pepper corns. At this time they are a solid mass of vegetable cells with a minute jelly-like center, which is the undeveloped larva. The growing larva devours the gall till at maturity nothing remains but a thin shell.

My galls were collected in October and were kept until late the next Summer under conditions as nearly normal as possible. As the flies seemed mature in August I placed the galls in dry boxes, expecting the insects would soon appear.

During October and November I removed from the galls some two hundred insects. They were somewhat torpid but seemingly mature. These were alive in January of the next year, and those in the galls had undergone no change. A few individuals emerged from the galls in the Winter, though most remained alive in the galls many months after.