Xylota quadrimaculata

Loew, 1866

Four-spotted Leafwalker

A common of found in central and eastern North America. are 8.2–11.3 mm long, black with distinctive -orange spots on the . Unlike most , adults rarely visit flowers, instead feeding on pollen from leaf surfaces. The develop in rotting wood under bark in sap runs.

Pronunciation

How to pronounce Xylota quadrimaculata: //zaɪˈloʊtə kwɑːˌdraɪmækjuˈleɪtə//

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Identification

Black body with four -orange spots on the . measure 8.2–11.3 mm in length. Distinguished from similar Xylota by the specific arrangement and coloration of abdominal spots. The is characterized by adults that rarely visit flowers, instead feeding on pollen from leaves—a behavioral trait that aids identification in the field.

Habitat

Woodland edges and forests with decaying wood. Associated with trees that have sap runs and rotting wood under bark.

Distribution

Central and eastern North America. Canada: Ontario, New Brunswick. United States: New York, Minnesota, Wisconsin, Illinois, New Hampshire, Massachusetts, Pennsylvania, Ohio, Iowa, Maine, Colorado, Mississippi, Tennessee, Maryland, New Jersey, Michigan.

Diet

feed on pollen grains from the surface of leaves rather than from flowers. Larval diet unknown specifically for this ; -level develop in rotting wood and sap runs.

Life Cycle

develop in rotting wood under bark in sap runs. emerge and are active during warmer months. Specific timing of developmental stages not documented.

Behavior

rarely visit flowers, unusual for . They feed on pollen from leaf surfaces instead. Adults may be observed basking on leaves in sunny conditions.

Ecological Role

Pollen feeder as ; contribute to wood decomposition in forest .

Similar Taxa

  • Chalcosyrphus spp.Similar size and (decaying wood), but Chalcosyrphus typically visit flowers and have different and body proportions. Xylota adults are distinguished by their leaf-feeding pollen and more slender build.
  • Other Xylota speciesRequire examination of abdominal spot pattern and precise measurements; X. quadrimaculata specifically has four -orange spots arranged in a characteristic pattern.

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