Gagne Description ³

Common, on most Eucarya hickories; on lower leaf surface on vein, usually clustered in a row along major vein and often in such close aggregation as to partially coalesce; 3.0-5.0 mm in height, spheroid to bilaterally compressed, sometimes pointed at apex, when coalesced bearing two or more larval chambers in an apparently single gall; covered with thick, mostly brown hair obscuring gall surface; base with small, irregular, shallow, central to off-center excavation; wall woody, thick, especially above, larval chamber irregularly ovoid, glabrous, green to brown. The gall of this species can be confused with several other spheroidconical, densely hairy galls, but its position along the major veins and usual crowding sets it apart from galls of the other species, e.g., C. holotricha and C. purpurea. Galls were described in Osten Sacken (1862) as a variant of typical galls of C. holotricha, but galls of the latter always have an apical intrusion of hairs in the larval chamber and oc- cur between instead of on the veins.

Gagne Biology Note ³

First noticed as full-size, hard galls in eastern West Virginia in early July, all were inhabited by second instars. By early August galls contained either a second or third instar. Full-grown larvae fully fill the larval chamber.

Sources and Credits

1. (c) Andrea Kautz, some rights reserved (CC BY-NC), uploaded by Andrea Kautz
2. (c) Adam Kranz, all rights reserved, uploaded by Adam Kranz
3. (c) Adam Kranz, some rights reserved (CC BY-SA)

More Info

• iNat taxon page
• Animal Diversity Web
• Biodiversity Heritage Library
• BOLD Systems BIN search
• BugGuide
• CUIC Insect Images
• Field/Photo ID for Flies
• Global Biodiversity Information Facility (GBIF)
• Guide to Hickory Midge Galls
• Guide to Hickory Midge Galls
• Maryland Biodiversity Project
• NatureServe Explorer 2.0
• Systema Dipterorum

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