Celticecis spiniformis

Celticecis aciculata

Celticecis semenrumicis

Celticecis acuminata

Celticecis capsularis

Celticecis celtiphyllia

Celticecis conica

Celticecis connata

Celticecis cornuata

Celticecis cupiformis

Celticecis expulsa

Celticecis globosa

Celticecis ovata

Celticecis oviformis

Celticecis pilosa

Celticecis pubescens

Celticecis pyriformis

Celticecis ramicola

Celticecis subulata

Celticecis supina

Celticecis wellsi

Peracecis fugitiva

Celticecis spiniformis 

Cecidomyiaceltis spiniformis
Cecidomyia unguicola New synonym.
Celticecis unguicola

Hosts. Celtis occidentalis, reticulata, laevigata, tenuifolia

Gall. On leaf lamina, usually on underside of leaf, often in groups; upright-conical; base flared, circular, flat to rounded; tapering evenly from base to sharply pointed apex; surface hairless, glabrous, green, turning yellow to tan; 4–6 mm high and 3–4 mm wide at base; connection to leaf circular, flat, ca. 1/3 width of gall base; apparent on opposite side of leaf as slight, sometimes discolored convexity; gall in cross section of variable thickness beneath and around base of subcylindrical larval chamber, thinning abruptly between distal third and fourth, at which level gall apex breaks off upon adult emergence in spring. 

Affinities. — Nine species of Celticecis appear to form a natural group: C. spiniformis, C. aciculata, C. acuminata, C. capsularis, C. conica, C. cupiformis, C. pilosa, C. subulata, and C. supina. All form galls on the leaf lamina except for C. supina whose galls are attached to veins, usually minor ones. 

Biological notes. Galls reach their ultimate length as a narrow cone before the base broadens to its full width, so young galls can at first be confused with those of C. subulata. The gall only later spreads out considerably at the base, which can be acute to well-rounded in cross section. When full-grown, the larva spins a cocoon that extends only to the narrow part of the larval chamber where the tip of the gall will break off in spring. Galls were already evident in late March in central Louisiana on only partly expanded leaves and were first noticed already with second instars in early May in Maryland. At least some full-grown larvae had already formed cocoons in mid-June in Louisiana and late June in Maryland. Many galls still with second instars can be found through mid-July so growth appears staggered. Some galls with cocooned larvae may remain attached to the leaves into September in Maryland and into November in Louisiana where the leaves remain on the tree longer. This longer duration on the leaves is a habit shared by most of the nine species of the C. spiniformis group, unlike most galls of the remaining species that tend to dehisce as soon as the larvae have formed their cocoons. 

Distribution (Map 18). — Celticecis spiniformis is a common, widespread species in the eastern half of the U.S., except in Florida where it is conspicuously absent. It is known from northern hackberry, sugarberry, dwarf hackberry and reticulated hackberry. 

AR, GA, IL, IO, KS, KY, LA, MD, MS, MO, NY, OH, PA, SD, TN, TX, VT, VA, WV, WI; absent in FL

Celticecis aciculata Gagne, new species

Hosts: Celtis laevigata, reticulata, tenuifolia

Description--Gall. On underside of leaf, rarely above, between veins, often in groups; usually cylindrical, sometimes widened at base, basal margin rounded or sharply angled, tip always abruptly narrowed a short distance before apex; glabrous, usually hairless, rarely with sparse, short, stiff hairs, green, turning tan to brown; 3.2–4.0 mm high and 2.0–2.5 mm wide at base; connection to leaf circular, flat, ca. 1/3 width of gall base, apparent on opposite side of leaf as slight discoloration, rarely as a small convexity; gall in cross section thickest surrounding base of cylindrical larval chamber, thinning gradually towards apex. 

Affinities.--See under C spiniformis [C spiniformis entry: Affinities. — Nine species of Celticecis appear to form a natural group: C. spiniformis, C. aciculata, C. acuminata, C. capsularis, C. conica, C. cupiformis, C. pilosa, C. subulata, and C. supina. All form galls on the leaf lamina except for C. supina whose galls are attached to veins, usually minor ones.]

Biological notes.--Occasionally, galls are splayed outwards basally as for galls of C. spiniformis, but C. aciculata galls are always abruptly narrowed apically rather than tapered. In Alexandria, Louisiana, galls can be found in early May when they already contain clear or white second instars. By mid-June many larvae have reached the third instar. By early July some have spun cocoons and have turned from white to light yellow, at least anteriorly. The cocoons abut the base of the nipple at the end of the gall. By the end of August galls begin to dehisce but many with viable larvae remain on the leaves until leaf drop in autumn. Gastrancistrus sp. from Alexandria, Louisiana and Torymus sp. from Sycamore Canyon Wilderness, Arizona were reared in spring from galls of C. aciculata collected the previous summer. 

Distribution.--A southern U.S. species found from Georgia and Florida and west to Arizona, C. aciculata was found on sugarberry, dwarf hackberry and netleaf hackberry. 

AZ, AR, FL, GA, LA, MS, TX

Celticecis semenrumicis (Patton)

Cecidomyiaceltis semenrumicis
Cecidomyia semenrumicis

Hosts: Celtis laevigata, occidentalis

Gall.--On twigs, occasionally on petioles or stronger veins on either side of the leaf; upright, with 3–6 prominent, longitudinal, narrow, lateral wings and long, slender, curled apex; surface hairless, matte, green turning tan, or wholly or partly red; 6–8 mm long, 4–6 mm wide at mid-length; connection to twig or leaf a broad, persistent callus; when on leaf apparent on reverse as a widened vein; gall in cross section an elongate-ovoid larval chamber surrounded by thin wall beyond which the wings radiate. 

Affinities.--Celticecis semenrumicis, C. ramicola, and C. ovata are distinguishable mainly from their galls. Galls of all three species are usually found attached to twigs. Those of C. semenrumicis ultimately develop distinct wings, are hairless, have a slender, curled apex, dehisce by early summer, and are known from the Mississippi Basin and Texas. Galls of C. ramicola have the same general distribution, are also hairless but never winged, have a short, straight apical extension, develop in late summer and early autumn and are slow to dehisce, in some cases persisting through late autumn. Galls of C. ovata are not sympatric with those of the other two, are instead more northern and eastern and hairy and wingless.

Biological note.--Galls first grow to their full length and only then develop wings. In Louisiana galls were found as early as late April on only partly expanded leaves, already with second instars. By June 6 only third instars were present, and galls dehisced readily although a few galls with viable full-grown larvae were found as late as August. 

Distr.--KS, LA, MO, TX


Celticecis acuminata Gagne, new species

Gall.--On lamina on underside of leaf, often in groups; upright, bulbous at base, tapering beyond mid-length to gall apex; green, turning tan or gray, covered with moderately long white hair, hair not obscuring granulose gall surface; ca. 4.0 mm long by 2.5 mm at widest; apparent on opposite side of leaf as an inconspicuous convexity; gall in cross section with elongate-ovoid larval chamber with thick, woody walls widest near mid-length. 

Affinities.--See under C spiniformis [C spiniformis entry: Affinities. — Nine species of Celticecis appear to form a natural group: C. spiniformis, C. aciculata, C. acuminata, C. capsularis, C. conica, C. cupiformis, C. pilosa, C. subulata, and C. supina. All form galls on the leaf lamina except for C. supina whose galls are attached to veins, usually minor ones.]

Biological notes.--Young galls were found in Alexandria, Louisiana on only partially expanded leaves. Galls could be found on leaves into September. The cocoon extends to the base of the tapered portion of the gall that breaks off upon eclosion of the adults. 

Distr.--This is an uncommon species found in southeastern and midwestern U.S. on northern hackberry, dwarf hackberry and sugarberry. It is one of the few species apparently absent from Louisiana [sic; observations from Louisiana are listed in the same paragraph and the following one] and Texas.

AR, FL, GA, IA, LA, MS, OH, VA, KY

Ceticecis capsularis (Patton)

Cecidomyiaceltis capsularis
Cecidomyia capsularis
Phytophaga painteri New synonym

Hosts: Celtis laevigata, occidentalis, tenuifolia, reticulata

Gall.--On leaf lamina on underside of leaf; depressed, circular, the sides conspicuously sulcate with 10 or more furrows, broadest at mid-length, apex with central spine; green, turning brown, granular, moderately longhaired but hairs not obscuring surface; ca. 2 mm high and 3–4 mm broad; connection to leaf conical, fitting into slight depression of leaf, a slight brown convexity apparent on reverse side of leaf; wall thick laterally, thin apically; larval chamber ovoid, extending the length of gall, lined with brittle tissue distinct from remainder of gall. 

Affinities.--See under C spiniformis [C spiniformis entry: Affinities. — Nine species of Celticecis appear to form a natural group: C. spiniformis, C. aciculata, C. acuminata, C. capsularis, C. conica, C. cupiformis, C. pilosa, C. subulata, and C. supina. All form galls on the leaf lamina except for C. supina whose galls are attached to veins, usually minor ones.]

Biological notes.--The gall grows lengthwise first, then laterally, developing the separate lobes as it expands. Full grown larvae are yellow and fill the entire cavity. In Alexandria, Louisiana galls with second instars were found in late March on newly expanded leaves and also later in the season. In Fort Pierce, Florida, fully-formed galls were found in early April. By mid-May some galls have fully-developed larvae. Galls with cocooned larvae may dehisce any time during the summer but many remain attached to the leaves through autumn. In spring pupae break through a circular opening that develops just below the apical spine. 

Distr.-- This is a southeastern U.S. species taken on all hackberries within its range. 

AR, FL, GA, LA, MS, TN, TX


Celticecis celtiphyllia (Felt)

Mayetiola celtiphyllia
Phytophaga celtiphyllia

Hosts: Celtis laevigata, occidentalis, tenuifolia

Gall.--On twigs, petioles or major veins on either leaf surface and often distorting the leaf, usually in crowded clusters; campanulate, the flattened apex with central, fluted, elongate projection; surface green, turning buff or brown, entirely covered with long hairs not obscuring surface, lower portion smoothly rounded, upper portion beyond widest dimension may be furrowed; ca. 6 mm long and 5 mm in diameter at greatest width, distal appendage a further 1–2 mm long; connection to plant not prominent, ca. 1/3 gall diameter; wall woody, thin near base, much thickened at mid-length and beyond, larval chamber pear-shaped, the larva living in larger basal portion. 

Biological notes.--For his gall description, Felt (1915b) cited Pergande’s unpublished notes, as follows: “very hard, obconic, the upper extremity produced as a long, slender nipple; at the base five or six low ridges. The galls are smooth inside and divided by a delicate though dense web into two compartments, the larva occurring in the lower.” This describes well the galls that are still at the USNM. The illustrations in Felt (1918, 1940) showed a separate series of young galls of this species growing on a stem, but their provenance was not indicated. With their slender shallotlike shape these galls look rather different from full-grown galls, but that is how the galls appear when the larvae are early second instars and before the galls broaden considerably. In Fort Pierce, Florida, galls were full grown with active second instars by March 7. Larvae had formed cocoons and were dehiscing by May 9. In both Louisiana and West Virginia, third instars were present by June 30. Galls did not always dehisce readily and were occasionally found with healthy larvae as late as September in West Virginia. Both second and third instars are very active and may be white to yellow-orange.

Distr.--This species is widespread in eastern U.S. on northern hackberry, dwarf hackberry and sugarberry.

AR, FL, GA, IA, KS, LA, MD, MS, OH, TX, WV

Celticecis conica Gagne, new species

Hosts: Celtis laevigata, occidentalis

Gall.--On leaf lamina on underside of leaf, found singly or in groups; upright, short-conical, evenly tapered from circular unsplayed base to narrowly rounded apex; hairless, glabrous, green, turning yellow to brown; ca. 2.5 mm high and 1.5 mm wide at base; connection to leaf circular, flat, ca. 1/3 width of gall base; apparent on opposite side of leaf as slight, sometimes discolored convexity; gall in cross section thick around base and thinning gradually toward apex, the subcylindrical larval chamber as long as gall. 

Affinities. — The gall of this species is the smallest gall on hackberries after that of C. cupiformis, but is evenly conical rather than barrel-shaped. See under C. spiniformis for further discussion. [C spiniformis entry: Affinities. — Nine species of Celticecis appear to form a natural group: C. spiniformis, C. aciculata, C. acuminata, C. capsularis, C. conica, C. cupiformis, C. pilosa, C. subulata, and C. supina. All form galls on the leaf lamina except for C. supina whose galls are attached to veins, usually minor ones.]

Biological notes.--In Maryland, galls were first noticed on May 12, already with second instars. Full grown larvae were found in late June and had formed cocoons by early July. Some galls persisted on the leaf at least through mid-September. Third instars are white until full-grown when the anterior half of the body turns yellow. 

Distr.--This species is widely distributed in the eastern half of U.S. and occurs on both northern hackberry and sugarberry. Its relative rarity may be due to its small size, causing it to be overlooked; still, the fact that it was never found in Texas but occurs in Louisiana and Arkansas is remarkable.

AR, GA, KY, LA, MD, OH, WV

Celticecis connata Gagne, new species

Hosts: Celtis laevigata, occidentalis, reticulata, tenuifolia

Gall.--Usually along twig, occasionally on fruit, petiole or major veins of upper side of leaf; spheroidal, often irregularly so, woody, often consisting of two or more coalesced galls, usually with short nipple at apex; hairless, surface shining, becoming matte, red or green, turning brown; 5–7 mm high, 5–12 mm wide; connection to host small in extent, not apparent; walls thick, woody, but thin below nipple, the larval chamber ovoid. 

Biological notes.--This is the only species of Celticecis to regularly form aggregate galls. In Alexandria, Louisiana, galls were found in late March before the leaves had hardened. By mid-April some galls contained small third instars, and by mid-May some larvae had formed cocoons. Galls begin to dehisce by mid-May, yet some remain on the twigs through November. Adults emerged from galls collected from Alexandria, Louisiana, and from Florida the spring following their collection, but emerged from galls collected from Pineville, Louisiana, and Bertram and Temple, Texas, only the second spring following their collection. 

Distribution. — This is a mainly southern U.S. species found on all available hackberries. 

AZ, GL, GA, KS, KY, LA, MO, TX, VA, 

Celticecis cornuata Gagne, new species

Hosts: Celtis laevigata, occidentalis, tenuifolia

Gall.--On major vein, usually on lower surface of leaf; upright, elongate-cylindrical, unevenly tapered beyond 2/3 length to rounded, weakly recurved apex; basal margin irregularly angled; surface glabrous, hairless, slightly furrowed, visible longitudinal veins slightly spiraling; green, usually turning red; 6–7 mm in length and up to 2 mm wide; connection to vein a prominent, circular, flat, persistent brown callus at least as wide as gall base; gall apparent on opposite side of leaf as slight thickening of vein; wall thin throughout, larval chamber of same shape as gall. 

Affinities.--The prominent callus that remains on the leaf after the gall dehisces is reminiscent of that seen in some stem galling species, e.g. C. ramicola.

Biological notes.--Galls were first noticed in Louisiana on March 26 on partially expanded leaves. Galls are usually green when young and turn red with age. Full grown larvae were present in late April in Temple, Texas and in mid to late May in Alexandria and Pineville, Louisiana. Any galls still found attached to the leaves later than May 30 contained either a dead larva or a parasitoid, so the larva had presumably stopped feeding before an abscission layer was formed that would have allowed the galls to dehisce. 

Distr.-- This species has a southerly U.S. distribution on sugarberry, northern hackberry and dwarf hackberry.

AR, FL, GA, KY, LA, MO, TX

Celticecis cupiformis Gagne, new species

Hosts: Celtis laevigata, reticulata

Gall.--On leaf lamina, usually on underside of leaf; short-cylindrical, basal margins abruptly rounded, apex broadly rounded and ending in short, central umbo; glabrous, hairless or sparsely hairy, the hairs not obscuring surface; green, turning mostly brown, the apex yellow; ca. 1.5 mm high and 1.0 mm wide; connection to leaf circular, flat, ca. 1/3 width of gall base and barely apparent from opposite side of leaf; gall in cross section uniformly thin, brittle, the larval chamber of same shape as gall. 

Affinities.--See under C spiniformis [C spiniformis entry: Affinities. — Nine species of Celticecis appear to form a natural group: C. spiniformis, C. aciculata, C. acuminata, C. capsularis, C. conica, C. cupiformis, C. pilosa, C. subulata, and C. supina. All form galls on the leaf lamina except for C. supina whose galls are attached to veins, usually minor ones.]

Biological note.--The gall of this rare species is very tiny, which may explain why it was not collected more often. Full-grown larvae are pink, red, or orange, and completely fill the larval cavity of the gall. 

Distr.-- This species is known only from southcentral U.S., on sugarberry with the exception of the Belton, Texas collection that was found on both sugarberry and netleaf hackberry growing side by side.

LA, TX

Celticecis expulsa Gagne, new species

Hosts: Celtis laevigata, occidentalis

Gall.--On stem, fruit, petiole and base of leaves; irregularly columnar, apically convex or flat, usually with short, central nipple, sometimes 2–3 galls partially coalesced, strongly convex on opposite side of petiole or vein and usually causing leaf distortion; base broad, integral to host tissue, developing apically a circular mark at apex, denoting margin where inner portion of the gall will emerge as a plug from the periphery and dehisce, the remainder of the gall shriveling; green, matte, with sparse white pubescence; 5 mm high, 3 mm broad; the deciduous plug yellow except for green apex, turning brown, larval chamber ovoid, the wall of the plug of uniform thickness.

Biological notes.--The gall of this species is the only one in North America that is not entirely detachable. Initially it appears as a simple columnar elevation of the plant tissue but eventually the interior of the gall surrounding the larval chamber separates as a distinct, hard, cylindrical core (Fig. 21). In due course the outer tissue shrivels, allowing the core to drop to the soil. In Alexandria, Louisiana, and Holland, Texas, galls were evident in early April, already with second instars. Most galls had dehisced by mid-May wherever the gall was found. Adults were reared in March and April, 2011, from galls taken in June, 2009, in Lawrence, Kansas. 

Distr.--Galls were found on both northern hackberry and sugarberry. This species may be more widespread than the distribution list indicates, but galls develop and excise earlier in the season than most of our collections were made.

KS, KY, LA, MD, TX, WV

Celticecis globosa Gagne, new species

Cecidomyia sp. Wells 1916: 273, Plate XVII, Fig 12a.

Hosts: Celtis laevigata, occidentalis

Gall.--Attached to leaf vein, usually on underside of leaf; ovate to globular, upright, often with lateral or encircling bulge near mid-length, apex flattened; light green, white to yellow, turning reddish, matte, hairless or, in most specimens from southcentral U.S. (Arkansas, Louisiana, Mississippi and Texas) covered with short pubescence not obscuring surface; ca. 3.0–3.5 mm long and 2.0–2.5 mm wide; apparent on opposite side of leaf as minute convexity; wall uniformly thin except at bulge when present, larval chamber ovate, shaped as for gall not including bulge. 

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.]

Biological notes.--The gall exterior is hairless (Fig. 22) or, in most specimens from Arkansas, Louisiana, Mississippi and Texas, fuzzy (Fig. 40). At the beginning of our study we kept these separate, but in the end we could find no other distinction between specimens of C. globosa from the hairy and non-hairy galls. This gall appears generally late in the season. In Alexandria, Louisiana, we noticed young galls with already developed second instars only in early July. These continued to develop long after galls of all other species except some C. pubescens were all mature. As late as September 25, some galls of C. globosa still contained second instars, although most contained third instars. By mid-October almost all galls contained third instars. Galls with viable third instars were still common on leaves on November 20, long after galls of most other species remaining on the leaves contained only dead larvae or parasitoids. In Kentucky, Ohio and Maryland, galls of C. globosa were also late, making it the most common gall collected in August and September. Larvae are usually white but some turn yellow to orange. 

Distr.--This is a widespread species in eastern U.S. on both northern hackberry and sugarberry.

AR, FL, IA, KS, KY, LA, MD, MS, OH, TX, VA, WV

Celticecis ovata Gagne, new species

Hosts: Celtis laevigata, occidentalis, tenuifolia

Gall.--On twigs, petioles or major veins of either leaf surface and often distorting the leaf, usually in crowded clusters; bulbous basally, the distal 1/3–2/3 gradually tapering to apex; connection to twig a pad as wide as gall base; surface green, turning brown, the surface then weakly longitudinally sulcate along entire length; covered with long white hair not obscuring surface; 5–6 mm long and 4–5 mm at widest diameter; wall woody, uniformly thick or thin, larval chamber of same shape as spheroid part of gall, not extending into tapered apical portion. 

Affinities.--See under C semenrumicis. [Affinities.--Celticecis semenrumicis, C. ramicola, and C. ovata are distinguishable mainly from their galls. Galls of all three species are usually found attached to twigs. Those of C. semenrumicis ultimately develop distinct wings, are hairless, have a slender, curled apex, dehisce by early summer, and are known from the Mississippi Basin and Texas. Galls of C. ramicola have the same general distribution, are also hairless but never winged, have a short, straight apical extension, develop in late summer and early autumn and are slow to dehisce, in some cases persisting through late autumn. Galls of C. ovata are not sympatric with those of the other two, are instead more northern and eastern and hairy and wingless.]

Biological notes.--The generally globular gall base becomes longitudinally sulcate when dried, lending the galls some slight resemblance to those of C. semenrumicis. young galls are similar to those of C. celtiphyllia, but those of the latter species eventually broaden apically and, when dry, may develop longitudinal sulcations only on the basal half. 

Distribution (Map 11). — This species was mainly found on northern hackberry but was found in southeastern Virginia on both northern hackberry and sugarberry growing next to one another and in Georgia on dwarf hackberry.

GA, IA, KY, MD, OH, VA, WV, WI

Celticecis oviformis (Patton)

Cecidomyiaceltis oviformis
Cecidomyia oviformis

Hosts: Celtis laevigata, occidentalis

Gall.--Usually along twig, occasionally on petiole or major veins of upper side of leaf, most often in groups; evenly spherical beyond obtuse, often weakly lobed base, with short apical nipple; green, turning brown, uniformly short-fuzzy but hairs not obscuring matte surface; 5–6 mm long, 4–5 wide; connection to host a prominent, circular, flat, persistent brown callus nearly 1/2 as wide as gall base; when on leaf apparent on opposite side of leaf as a thickening of vein; wall of uniform thickness throughout, larval chamber spherical, of same shape as gall. 


Biological notes.--Galls of this species have a similar shape to those of C. connata when those of the latter are not found in aggregate, but galls of C. oviformis are covered with fine pubescence and are uniformly thin-walled, unlike galls of C. connata that are hairless and have thick walls of irregular diameter. Galls of C. oviformis develop and dehisce early in the season, possibly why it was not collected more often. In mid-April when galls were first noticed in Alexandria, Louisiana, they already contained second instars. After mid-May galls of this species still found attached to the host were parasitized. 

Distr.--This species is widespread in the U.S. and found on both northern hackberry and sugarberry. 

FL, IL, KS, LA, MD, MO, OH, WV, TX

Celticecis pilosa Gagne, new species

Hosts: Celtis occidentalis

Gall.--On leaf lamina on underside of leaf, usually in groups; uprightconical, apex pointed, base circular, not flared; surface covered with white hair nearly obscuring green surface; 3.5–4.5 mm high and 2.0–3.0 mm wide at base; connection to leaf circular, flat, ca. 1/3 width of gall base; apparent on opposite side of leaf as slight, sometimes discolored convexity; gall in cross section thickest near base surrounding larval chamber, thinning and less woody and more brittle apically. 

Distr.-- This species was the most rarely collected species of Celticecis. It was found only on northern hackberry.

KY

Celticecis pubescens (Patton)

Cecidomyiaceltis pubescens
Cecidomyia pubescens
Phytophaga texana New synonym

Hosts: Celtis laevigata, occidentalis, reticulata

Gall.--On underside of leaf, in vein fork, occasionally two adjacent in a fork and then sometimes partly or wholly coalesced, usually perpendicular to leaf; stout cylindrical with short apical tubercle in center of flattened apex and base abruptly tapering to short peduncle; surface green, turning brown, with or without long white pubescence that may sometimes obscure surface; ca. 4 mm long and 3 mm in diameter; apparent on opposite side of leaf as slight, sometimes discolored convexity; walls in cross section thick, yellowish, woody, larval chamber elongate-ovoid, nearly as long as gall. 

Affinities.--This species 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. 

Biological notes. — Young galls of this species bearing second instars were seen in late April and mid-May in Louisiana, but young, soft galls continued to appear through July. Galls with full- grown larvae are commonly found in August but some still contain second instars. Full-grown larvae are yellow to orange and fill the larval chamber. Persistent galls found later than August are generally parasitized; many galls of the current season can be found with a parasitoid's exit hole at the very base of the gall. Adult C. pubescens were reared in spring of 2010 and 2011 from galls collected in summer of 2009 in Temple, Texas.

Distribution (Map 14). — This is a southern U.S. species known from Florida to Arizona and found on sugarberry, netleaf hackberry and northern hackberry. 

AZ, AR, FL, LA, TX


Celticecis pyriformis Gagne, new species

Unnamed species, Riley 1890

Hosts: Celtis occidentalis

Gall.--Attached singly or serially to more prominent leaf veins on underside of leaf, occasionally adjacent galls partially fused; generally cylindrical, becoming bulbous at base, upright to recumbent, apex flat except for short central nipple; green turning yellow, sparsely to densely covered with long, crinkly white hair of variable length; 3–4 mm long and 2–3 mm broad at base; connection to vein conspicuous, often causing swelling of vein nearby and appearing as a convexity on opposite side of leaf; mature gall in cross section woody, wall of uniform thickness or thickest basally and thinning beyond mid-length, larval chamber elongate ovoid, nearly as long as gall. 

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.]

Biological note.--In Maryland galls were first found in early June already with yellow second instars. By mid-July some galls contained either second or third instars and in mid-August larvae were in the third instar and the larval chambers were lined with silk. Once, at Falling Waters, West Virginia, a gall contained a predaceous Lestodiplosis larva feeding on the C. pyriformis larva. A hole was present at the base of the gall, but it is doubtful that the Lestodiplosis made the hole. 

Distribution (Map 15). — This species is known only from northern hackberry and has a northerly U.S. distribution, from Kansas to Maryland. 

KS, KY, MD, IL, MO, OH, WV

Celticecis ramicola Gagne, new species

Hosts: Celtis laevigata

Gall.--Usually on stem, occasionally on petiole or base of leaf and then often crowded and distorting leaf; closely placed galls may be partially connate; cylindrical or subcylindrical, abruptly tapering distally to narrow, elongate apex; connection to plant as wide as gall, apparent on other side when on leaf as a conspicuous convexity; hairless, granulose, may be weakly furrowed longitudinally, green, eventually turning brown; 3.0–4.0 mm high, ca. 2.5 mm in diameter; wall eventually woody, uniformly thin throughout, larval chamber of same shape as gall. 

Affinities.--See under C. semenrumicis concerning the close similarity and presumed affinity among it, C. ramicola and C. ovata. [Celticecis semenrumicis, C. ramicola, and C. ovata are distinguishable mainly from their galls. Galls of all three species are usually found attached to twigs. Those of C. semenrumicis ultimately develop distinct wings, are hairless, have a slender, curled apex, dehisce by early summer, and are known from the Mississippi Basin and Texas. Galls of C. ramicola have the same general distribution, are also hairless but never winged, have a short, straight apical extension, develop in late summer and early autumn and are slow to dehisce, in some cases persisting through late autumn. Galls of C. ovata are not sympatric with those of the other two, are instead more northern and eastern and hairy and wingless.]

Biological note.--Galls of this species mostly appear late in the season. Although seen as early as May in Alexandria, Louisiana, they were much more common there from August through October. In late September, many still contained second instars but by October all contained third instars. This is the only gall we have seen that may persist on branches into the next spring, and then not with viable larvae but with dead larvae or parasitoids. This gall may appear similar to those of C. aciculata. Galls of the latter species are always on the leaves and their attachment to the leaf is only half the diameter of the gall. Galls of C. ramicola are usually on twigs and their attachment to the substrate is at least as wide as the gall. The larvae of the two species are distinct. 

Distribution (Map 16). — This species is restricted to southeastern U.S. and has been found only on sugarberry.

GA, LA, MS, TN, TX


Celticecis subulata Gagne, new species

Hosts: Celtis laevigata, reticulata, tenuifolia

Gall.--On leaf lamina, usually on underside of leaf, single or in groups; upright, elongate-conical, tapering evenly from sharply angled base to pointed apex; surface glabrous, green, turning tan to brown; 6–9 mm high and 2–3 mm wide at base; connection to leaf circular, flat, ca. 1/2 width of gall base, apparent on opposite side of leaf as slight discoloration, rarely as small convexity; gall in cross section thin-walled especially beyond 2/3 height, the cylindrical larval chamber extending from base of gall to apex. 

Biological notes.--In central Louisiana, young galls can be found already with second instars in late March on partly expanded leaves. Fullgrown, cocooned larvae as well as some larvae still in the second instar were found in galls in late May. Galls may remain on the leaves through the season and dehisce in September and October. Cocoons extend from the bottom of the larval chamber to about 2/3 height at which point the gall will easily divide the following spring. Larvae are white until later in the third instar when their anterior half turns yellow. 

Distribution (Map 19). — This southern U.S. species is found from Georgia and Florida west to Arkansas and Texas.

AR, FL, GA, LA, MS, TX


Celticecis supina Gagne, new species

Cecidomyia sp. Wells 1916: 273.

Hosts: Celtis laevigata, occidentalis, reticulata

Gall.--Reclinate along major or minor veins, almost always on lower leaf surface; subcylindrical, tapering gradually or just before apex; surface striate to rugose, green at first, turning yellow to tan, usually with sparse white hair not obscuring gall surface; 3–4 mm long, 1–2 mm wide near base; wall thin, larval chamber shaped as for gall; gall on opposite side of leaf apparent as a slight discolored convexity. 

Affinities. — The tiny galls of this species produce small adults that are among the smaller ones in Celticecis. See under C. spiniformis for further discussion. [Nine species of Celticecis appear to form a natural group: C. spiniformis, C. aciculata, C. acuminata, C. capsularis, C. conica, C. cupiformis, C. pilosa, C. subulata, and C. supina. All form galls on the leaf lamina except for C. supina whose galls are attached to veins, usually minor ones.]

Biological notes. — This early-developing gall was evident in early May in Louisiana and by mid-May in Maryland, in both places already with second instars. In Louisiana galls found with third instars by May 23 in which some had cocooned by June 13. Cocoons fill the larval cavity except for the narrower apex that breaks off when adult emerges in spring. 

Distribution (Map 20). — This species is generally widespread in eastern U.S. except that it appears to be absent in the southeast. It is found on northern hackberry, sugarberry and netleaf hackberry.

IA, KS, KY, LA, MD, MO, OH, TN, TX, WV

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

Peracecis fugitiva Gagne, new species

Hosts: Celtis laevigata, occidentalis, tenuifolia

Gall.--On leaf, an integral spherical blister usually of the leaf underside, and a narrow chimney on the opposite surface through which the full grown larvae eventually exit; green, the same color as the leaf, matte, with short white pile on the blister side, bare on the other; blister 4–7 mm in diameter, 3–4 mm high, the chimney on opposite side of leaf ca. 2 mm long; gall thin-walled, no thicker than normal leaf tissue. 

Biological notes.--Galls appear early in spring and were first noticed on April 16 in Alexandria, Louisiana and on April 7 in Holland, Texas when the larvae were already in their third instar. On May 3 to 9 in Alexandria larvae appeared fullgrown, and by May 19 most had dropped to the soil. In Bibb County, Georgia a few larvae were recovered from galls collected on June 3. Galls are integral to the leaves so their shrivelled remains can be found throughout the season where they occur. Third instars are white, spindle-form and very active. As many as 15 larvae may be found in one gall. Peracecis larvae were observed crawling out of the galls through the chimney on the upper leaf surface. 

Distribution (Map 22). — This mainly southern species does not appear to distinguish among hackberries.

GA, KS, LA, TX

The North American Gall Midges (Diptera: Cecidomyiidae) of Hackberries (Cannabaceae: Celtis spp.)