Chrysaster ostensackenella
(Fitch, 1859)
A small leaf-mining in the , to eastern North America and recently established as an pest in East Asia, Europe, and Russia. have a wingspan of approximately 4–5 mm. feed exclusively on Robinia , creating distinctive blotch mines on leaves. The species has spread rapidly through human-mediated transport of plants and is expected to expand further in regions where black is planted.
Pronunciation
How to pronounce Chrysaster ostensackenella: /ˈkɹɪsæstər oʊstɛnˌsækəˈnɛlə/
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Identification
Distinguished from other by pattern and male ; leaf mines are diagnostic—yellowish blotch mines on upper leaf surface with short initial tunnel (1.5–2 mm) following secondary . deposited in dotted central in tunnel portion, scattered as black grains in blotch with highest concentration centrally. occurs outside the mine on lower leaf surface in (in Russian ; North populations pupate inside mine).
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Habitat
Arboreta, tree plantings, and urban landscapes where Robinia occur; in invaded range, found in ornamental plantings of black (Robinia pseudoacacia). range includes deciduous forests and urban areas with trees.
Distribution
to eastern North America: Canada (Ontario, Québec, Nova Scotia) and United States (Illinois, Kentucky, New York, Maine, Maryland, Michigan, Vermont, Arizona, Massachusetts, North Carolina, Connecticut, Tennessee, Virginia). range: China (2015), South Korea (2017), Japan (2021), Italy (2022), and Russia (Primorsky Krai, 2022). Expected further spread in East Asia and Europe due to widespread black planting.
Seasonality
Likely two per year in Primorsky Krai; up to four generations reported in China. active in July in Russian Far East; seasonal timing varies across range.
Diet
feed on leaves of Robinia (Fabaceae), specifically Robinia pseudoacacia, R. hispida, R. neomexicana, and R. viscosa. Leaf-mining larvae consume leaf tissue between upper and lower .
Host Associations
- Robinia pseudoacacia - primary Black ; main supporting spread
- Robinia hispida -
- Robinia neomexicana -
- Robinia viscosa -
Life Cycle
laid near main or between main and secondary vein. Early creates short tunnel (1.5–2 mm) following secondary vein, then widens into blotch mine. -greenish, up to 4 mm; single larva per mine. Late instar creates semicircular cut in upper for escape. occurs outside mine on lower leaf surface in tough along secondary vein (Russian ); North populations pupate inside mine. Pupal development up to 6 days at 24°C and 45% humidity.
Behavior
occurs near leaf . deposition pattern distinctive: dotted central in tunnel, scattered black grains in blotch. disperse via wind currents as air plankton or hitchhike on human transport; stages transported with plants for planting.
Ecological Role
and pest; causes leaf discoloration, browning, drying, and premature leaf fall. During , causes significant damage to ornamental . No known or associations documented in invaded range.
Human Relevance
pest of ornamental and forestry plantings of black . Economic impact on urban landscaping and Robinia . Spread facilitated by international trade in plants. Genetic studies used to trace invasion routes and inform management.
Similar Taxa
- Other Gracillariidae on RobiniaSimilar leaf-mining habit; distinguished by mine (blotch mine with short initial tunnel, pattern) and site
- Phyllonorycter robiniellaAlso mines Robinia leaves; distinguished by mine shape, pattern, and