Agromyza aristata

Adults are small flies typical of the family Agromyzidae. The species is distinguished from other elm-feeding agromyzids by its serpentine leaf mine pattern in Ulmus leaves. Larvae can be identified within mines by their characteristic feeding trail. The species can be separated from the related Phytomyza genus by wing venation and male genitalia characters, though specific diagnostic features for A. aristata require microscopic examination.

Urban landscapes, parks, and natural areas with elm trees (Ulmus spp.). Occurs in open, grassy areas where host elms are present. Found in both cultivated and wild settings where American elm grows.

Widespread throughout eastern North America. Documented in Kentucky (Lexington), Vermont, and across the United States. The species' range corresponds with that of its primary host, American elm.

Active during the growing season when elm leaves are available. In Kentucky, leaf mines are initiated in late April and completed by mid- to late May. Adult activity and oviposition occur during spring leaf expansion.

Phytophagous. Larvae feed internally on leaf mesophyll of elm species (Ulmus spp.), creating serpentine mines. Strong preference for American elm (Ulmus americana) documented in field trials; less abundant on Asian elms and hybrids.

• Ulmus americana - primary hostStrongly preferred; highest mining densities observed on this species
• Ulmus parvifolia - secondary hostLess susceptible; Asian elm with lower infestation rates
• Ulmus propinqua - secondary hostLess susceptible; Asian elm with lower infestation rates
• Ulmus spp. hybrids - hostVarious Dutch elm disease-resistant hybrids show intermediate susceptibility

Larvae develop within serpentine leaf mines in expanding elm leaves. Pupation occurs within the mine or in soil. Adults emerge to feed and oviposit. In Kentucky, mines initiated in late April are completed by mid- to late May. New adults emerge by late May and early June.

Creates serpentine (winding, linear) leaf mines in elm foliage. Females lay eggs in expanding leaves during spring. Larval feeding produces visible trails as they tunnel through leaf mesophyll between upper and lower epidermis. Mines typically widen slightly as larvae mature.

Leaf-mining herbivore that contributes to foliar damage in elm trees. Acts as a pest in urban landscape settings, reducing aesthetic value of ornamental elms. Part of the guild of leaf-feeding insects associated with Ulmus species.

Considered a pest of ornamental and landscape elms. Contributes to foliar damage in urban tree plantings, particularly on American elm cultivars. Implications exist for re-introduction of elms into urban landscapes, as host preference patterns affect cultivar selection for resistance breeding programs.

• Phytomyza spp.Other agromyzid leaf miners on Ulmus; distinguished by mine pattern, host preference, and adult morphology
• Kaliofenusa ulmiBlotch-mining sawfly on elms; creates blotch mines rather than serpentine mines, and belongs to different order (Hymenoptera)

• leaf miner
• pest
• Ulmus
• serpentine mine
• urban forestry

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life
• Encyrtid Holdings | Entomology Research Museum
• Earth’s oldest living things! | Beetles In The Bush
• Pinaceae | Beetles In The Bush
• Resistance of Landscape-Suitable Elms to Japanese Beetle, Gall Aphids, and Leaf Miners, with Notes on Life History of Orchestes alni and Agromyza aristata in Kentucky