# Elm Leafminer (*Fenusa pusilla*) The Elm Leafminer is a tiny insect that loves to munch on elm leaves. It makes little tunnels inside the leaves, which can look like tiny mazes! These insects are interesting to watch as they create their homes in the leaves. - **Category:** [Insects](https://www.snappit.app/explore/categories/insect) - **Rarity:** Common - **Danger:** 1/5 · Very low - **Habitat:** Urban areas ![Elm Leafminer](https://inaturalist-open-data.s3.amazonaws.com/photos/38888411/medium.jpg) Photo: Rebecca Ray, CC BY 4.0 · [iNaturalist](https://www.inaturalist.org/photos/38888411) ## Appearance The Elm Leafminer is a tiny, shiny black sawfly with an oval-shaped body and yellowish-white legs. Its wings are clear and membrane-like, often appearing slightly smoky. It can be visually differentiated from other small dark insects by its characteristic sawfly appearance, lacking the narrow 'wasp waist' of true wasps. ## Taxonomy - **Kingdom:** Animalia - **Phylum:** Arthropoda - **Class:** Insecta - **Order:** Hymenoptera - **Family:** Tenthredinidae - **Genus:** Fenusa ## Interesting facts - Each Elm Leafminer larva lives entirely hidden inside an elm leaf, eating its way through the middle! - Female leafminers use a special saw-like tool on their body to tuck their eggs right inside elm leaves! - These tiny insects are sawflies, not moths or beetles, making them distant relatives of wasps! - They spend the whole winter sleeping underground as pupae, waiting for spring to arrive! ## Special abilities - **Saw-like Ovipositor:** Elm Leafminer has a special saw-like tool that helps them cut tiny slits into elm leaves to lay eggs safely inside. - **Leaf Burrower:** Elm Leafminer larvae can live and feed entirely inside an elm leaf, protected from many dangers because of their habitat. - **Underground Sleeper:** Elm Leafminers can spend the entire winter as pupae buried in the soil, safely waiting for spring because of this ability. ## Measurements & details - **Wingspan:** 8-10 mm - **Size:** 4-5 mm - **Lifespan:** 7-14 days - **Flight Speed:** 7 km/h - **Leg Count:** 6 ## Diet & Feeding Elm Leafminer larvae feast on the tender inner tissues of elm leaves, while adults may sip nectar. - **Age differences:** Larvae consume leaf tissue; adults are thought to feed sparingly on nectar or not at all. - **Primary Foods:** Ulmus americana leaves, Ulmus minor leaves, Ulmus glabra leaves, Ulmus pumila leaves - **Foraging Method:** Null ## Ecological connections - **Eats:** [American Elm](https://www.snappit.app/explore/american-elm) (*Ulmus americana*) — Larvae feast on the tender inner layers of its leaves. - **Eats:** [Field Elm](https://www.snappit.app/explore/field-elm) (*Ulmus minor*) — Their primary food source are the nutrient-rich tissues inside its leaves. - **Eats:** [Wych Elm](https://www.snappit.app/explore/wych-elm) (*Ulmus glabra*) — Its leaves are a common food source for the developing larvae. - **Parasitizes:** Ichneumonid Wasp (*Adelognathus americanus*) — Its larvae develop inside the Elm Leafminer larvae. ## Traits - [Solitary](https://www.snappit.app/explore/traits/solitary): Solitary animals live alone for most of their lives, only interacting with others for mating or parental care. - [Herbivorous](https://www.snappit.app/explore/traits/herbivorous): This trait characterizes organisms whose diet consists entirely or primarily of plant material. - [Diurnal](https://www.snappit.app/explore/traits/diurnal): Diurnal animals are primarily active during daylight hours, typically resting or sleeping at night. - [Miniature](https://www.snappit.app/explore/traits/miniature): Pertaining to species that are significantly smaller than typical or average for their kind. - [Urban Friendly](https://www.snappit.app/explore/traits/urban-friendly): This habitat trait indicates species that can coexist with humans in urban and suburban environments, utilizing man-made structures and green spaces. - [Pollinator](https://www.snappit.app/explore/traits/pollinator): Describes organisms that transfer pollen, enabling the fertilization and reproduction of plants. ## Collections - [Insects](https://www.snappit.app/explore/collections/insects) ## Safety **Danger:** 1/5 · Very low It's best to look at insects from a distance and not touch them. ## Frequently Asked Questions ### How to identify Elm Leafminer? Look for six legs, antennae, three body sections and the shape of the wings. Beetles have hardened front wings; flies have just one working pair. Tiny insects may need a close view before their group is clear. Insect Identifier: upload a photo and compare the visible details. ### What is Elm Leafminer's wingspan? 8-10 mm ### How big is Elm Leafminer? 4-5 mm ### How long does Elm Leafminer live? 7-14 days ### How fast can Elm Leafminer fly? 7 km/h ### What does Elm Leafminer eat? Elm Leafminer larvae feast on the tender inner tissues of elm leaves, while adults may sip nectar. ### Where is Elm Leafminer usually found? Urban areas ### How does Elm Leafminer hunt? Null ## Where to spot - [Okanagan Lake Provincial Park](https://www.snappit.app/guides/places/okanagan-lake-provincial-park) — British Columbia, CA · State Park ## More Insects - [Common Eastern Bumble Bee](https://www.snappit.app/explore/common-eastern-bumble-bee) (*Bombus impatiens*) - [Spotted Lanternfly](https://www.snappit.app/explore/spotted-lanternfly) (*Lycorma delicatula*) - [Brown-belted Bumble Bee](https://www.snappit.app/explore/brown-belted-bumble-bee) (*Bombus griseocollis*) - [Eastern Carpenter Bee](https://www.snappit.app/explore/eastern-carpenter-bee) (*Xylocopa virginica*) --- Source: [Elm Leafminer: Facts & Places to See — Snappit](https://www.snappit.app/explore/elm-leafminer)