(Epistrophe grossulariae)
Conservation • Description • Habitat • Biology • Distribution • Taxonomy
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Description |
Black-horned smoothtail is a moderately large, late-season, typical hover fly. It occurs in Europe and North America. In the United States, it occurs in the east from Maine to Pennsylvania, west to Minnesota, and south along the Appalachian Mountains to northern Georgia. It also occurs in the Pacific Northwest. It occurs across southern Canada from Nova Scotia to British Columbia, and north along the West Coast to Alaska. It is uncommon in Minnesota. Adults are active from early May to October in other parts of their range, but in Minnesota, they have been seen only from July 16 to September 30. They are found in forests, meadows, fields, and along streams. They feed on flower nectar and pollen. The larvae prey on aphids. Adults are 7⁄16″ to ⅝″ (10.4 to 15.0 mm) in length. The body is robust and black or brownish black (dark) and yellow. On the male, the head is hemispherical and wider than the thorax. The back of the head is strongly concave and closely appressed to the thorax. There are two large compound eyes on the sides of the head and three small simple eyes (ocelli) in a triangle on top of the head. The compound eyes are bare, with no hairs, and they meet at the top of the head. The face is pale yellow, and there is an obscure, brownish, longitudinal stripe in the middle on the lower three-fifths. The protruding mouthpart (proboscis) is short and fleshy. The antennae are short, shorter than the head, and they have three segments. They are usually entirely black, but on some specimens the first segment (scape) is yellowish on the underside. On the third segment there is a stiff, forward-pointing bristle (arista). The arista is bare, not feather-like (plumose). The yellow on the face continues above the antennae on each side to the top of the compound eyes, defining a long, black, isosceles triangle in the middle. There is no yellow directly above the antennae bases. The thorax is large and it has three segments. Each segment has four principal exoskeletal plates, one above, one below, and one on each side. The upper (dorsal) plates, from front to rear, are the prescutum, scutum, and scutellum. The scutum is large, rounded, shiny, and entirely yellow. The hairs on its surface are almost all black. On each side of the scutum, in the shoulder (humeral) area just behind the head, there is a small plate (postpronotum). The postpronotum is bare, with no hairs or bristles. Unfortunately, this is not visible without first removing the fly’s head. The scutellum is large, rounded, shiny, and entirely yellow. On each side of the thorax, the lower front plate of the middle segment (katepisternum) has an upper and a lower patch of hairs. The upper and lower patches are narrowly joined at the rear. On the underside of the thorax, on each side, there is a small area (metasternum) in front of the first segment (coxa) of the front legs. The metasternum has many long pale hairs. The abdomen is broadly oval to narrowly oval, and it is narrowly flattened (margined) on the sides. It has five visible segments (tergites). The first segment (T1) is short and black above. T2 has a pair of large yellow spots that broaden toward the sides and extend over the front half to two-thirds of the margin. T3 and T4 have a broad yellow band at the front margin. The band does not narrow at the lateral margins. T4 also has a broad band on the rear margin. On the front legs, the first segment (coxa) is yellow to brown. On the middle and hind legs, the coxa is brown to black. On each leg, the third segment (femur) is mostly yellow. On the front and middle legs, the basal fifth or less of the femur is brown to black. On the rear legs, the basal half or less is brown to black. The wings are clear. The entire wing surface is covered with minute hairs (microtrichose). On the female, the compound eyes do not meet at the top of the head. The dark stripe on the face may be narrow or broad but it is always distinct. The femur on the hind legs is often entirely yellow. |
Size |
Total length: 7⁄16″ to ⅝″ (10.4 to 15.0 mm) |
Similar Species |
Habitat |
Forests, meadows, fields, and along streams |
Biology |
Season |
One generation per year: July through September |
Behavior |
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Life Cycle |
Larvae overwinter |
Larva Food |
Aphids |
Adult Food |
Flower nectar and pollen |
Distribution |
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Sources |
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12/18/2024 | ||
Occurrence |
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Common in the northeast. Uncommon in Minnesota |
Taxonomy |
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Order |
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Suborder |
Brachycera |
Infraorder |
Cyclorrhapha |
Zoosection |
Aschiza |
Superfamily |
Syrphoidea |
Family |
Syrphidae (hover flies) |
Subfamily |
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Tribe |
Syrphini |
Genus |
Epistrophe |
Subordinate Taxa |
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Synonyms |
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Epistrophe conjugens Epistrophe formosa Musca formosus Stenosyrphus grossulariae Syrphus grossulariae Syrphus lesueurii Syrphus melanis |
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Common Names |
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black-horned smoothtail |
Glossary
Arista
A large bristle on the upper side of the third segment of the antenna of a fly. Plural: aristae.
Coxa
The first segment of the leg of an insect, attaching the leg to the body, and connected to the trochanter. Plural: coxae.
Femur
On insects and arachnids, the third, largest, most robust segment of the leg, coming immediately before the tibia. On humans, the thigh bone.
Ocellus
Simple eye; an eye with a single lens. Plural: ocelli.
Proboscis
The protruding mouthpart(s) of a sucking insect.
Scape
In plants: An erect, leafless stalk growing from the rootstock and supporting a flower or a flower cluster. In insects: The basal segment of the antenna.
Scutellum
The exoskeletal plate covering the rearward (posterior) part of the middle segment of the thorax in some insects. In Coleoptera, Hemiptera, and Homoptera, the dorsal, often triangular plate behind the pronotum and between the bases of the front wings. In Diptera, the exoskeletal plate between the abdomen and the thorax.
Scutum
The forward (anterior) portion of the middle segment of the thorax (mesonotum) in insects and some arachnids.
Tergite
The upper (dorsal), hardened plate on a segment of the thorax or abdomen of an arthropod or myriapod.
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Here's another black-horned smoothtail taken a few days after the previous one I sent. 9/7/24. They must like the white snakeroot (it's spreading around the edge of the yard). |
Bee on white snakeroot. |
MinnesotaSeasons.com Photos |
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Slideshows |
Epistrophe grossulariae |
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Epistrophe grossulariae |
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About
Epistrophe grossulariae |
Visitor Videos |
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Other Videos |
Hoverfly Epistrophe grossulariae |
About
Mar 29, 2013 The handsome social wasp-mimicking Hoverfly Epistrophe grossulariae has two pale thoracic stripes on the bronze-coloured thorax that assist the observer with identification (as there are many similarly marked hoverflies). The feeding behaviour is distinctive as when feeding from thistles Carduus spp. this fly will often continue to hover with its front legs touching a flower rather than alighting. |
Epistrophe grossulariae feeding |
About
Jul 27, 2015 Epistrophe grossulariae hoverfly feeding at Langold Lake Worksop |
Black-horned Smoothtail (Epistrophe grossulariae) |
About
Jun 10, 2024 Black-horned Smoothtail (Epistrophe grossulariae) on Portland |
Epistrophe grossulariae - Zwartsprietbandzweefvlieg |
About
May 3, 2020 Epistrophe grossulariae foraging on Plantago media. Filmed september 2018 at Torgny (Belgium). |
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Location: Lake Shore, MN Bee on white snakeroot. |
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MinnesotaSeasons.com Sightings |
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Created: 12/18/2024 Last Updated: © MinnesotaSeasons.com. All rights reserved. |