Gagne Description ²

Common, on Eucarya hickories; on lower leaf surface between veins, usually clustered; 2.0-3.0 mm in height, cylindrical, usually slightly wider than long, conical at base, circular, flat to concave at apex; lateral surface tan to brown, shiny, viscid, the apex orange to brown, crusty, thickly mucillaginous; subtending leaf tissue with conspicuous, extensive, irregular exfoliation surrounding base of gall, corresponding top surface of leaf usually discolored, convex; lateral wall of larval chamber firm, brittle, thin laterally, apical wall usually thicker, larval chamber glabrous, with longitudinal ridges. These galls can sometimes be confused with those of mature, dried C. flaticrustum galls, but galls of the latter lack the conspicuous leaf exfoliation surrounding the base of galls of C. melicrustum.

Gagne Biology Note ²

In late May in Central Maryland, one can find young galls not yet completely broken out of the leaf covering and simulating young galls of C. hibicola (Fig. 74) and containing first instars. In mid- to late June, galls are full size but still soft and contain first and second instars. In August one can still see green, softer galls with second instars, but also harder, brown galls with third instars. Pupae emerge from a hole in the thinner walls adjacent to the conical base.

Sources and Credits

1. (c) Adam Kranz, all rights reserved, uploaded by Adam Kranz
2. (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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