Platycheirus Granditarsus on:
[Wikipedia]
[Google]
[Amazon]
''Platycheirus granditarsus'', the Hornhand Sedgesitter, is a
Speight key to genera and glossary
;Size
;Head
The face is nearly vertical and the anterior oral margin is produced forward. It is shining, with silver pollinosity present only at lateral edges. The tubercle is somewhat large and abruptly pointed. The vertex is narrow, approximately two times as wide as the ocellar triangle. The antenna is black.
;Thorax
The thorax is shining to subshining black and the pile is white or pale yellow. The longest scutellar pile is approximately equal in length to the arista, while other thoracic pile is half as long.
;Abdomen
For male specimens, the abdomen is oval, with extensive orange areas. Segment 2 usually has only the anterior and lateral edges black, sometimes with a median black line. Segment 3 has only posterolateral edges black, while segment 4 usually has a basal half that is black, occasionally with a median black line that divides the orange anterior half of the segment into two large spots. Segment 5 is dark and unmarked. The surstylus has a poorly developed basal process
external images
For female specimens, the abdomen is broadly oval, with orange areas similar to males. Segment 2 usually has all edges black, sometimes with a median black line. Segment 3 has a complete posterior black band and sometimes also a median black band that divides the orange area into two spots. Segment 4 usually has a basal half that is black, often with a median black line that divides the orange anterior half of the segment into two large spots. Segment 5 has anterior orange spots. ;Wings The wing is darkened, entirely microtrichose.
;Legs
The legs are mostly dark, with broad apices of femora and bases of tibiae pale. The fore femur has short, stiff black setae spaced irregularly on the anteroventral and posteroventral surface. The first fore tarsomere has a large, anterior triangular process on the apical half. The first 4 tarsomeres of the mid leg are strongly flattened, each with a broad, apically rounded process which are progressively shorter from the first to third tarsomere
External images
image:Syrphid leg diagram.png , Legs
image:Head diagram.png, Head
image: Platycheirus wing diagram.jpg, Wing
image: Syrphid body1.png, Body
See references for
A19
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of hoverfly
Hoverflies, also called flower flies or syrphids, make up the insect family Syrphidae. As their common name suggests, they are often seen hovering or nectaring at flowers; the adults of many species feed mainly on nectar and pollen, while the l ...
. It is found in many parts of Britain
Britain most often refers to:
* Great Britain, a large island comprising the countries of England, Scotland and Wales
* The United Kingdom of Great Britain and Northern Ireland, a sovereign state in Europe comprising Great Britain and the north-eas ...
North America and Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
. Typical habitat includes marshy meadows and ditches, where it can be found between May and October, though it is at its commonest between July and September. The most distinctive feature of this fly is the red-orange abdomen most easily seen as it takes off or alights.
Description
For terminologySpeight key to genera and glossary
;Size
;Head
The face is nearly vertical and the anterior oral margin is produced forward. It is shining, with silver pollinosity present only at lateral edges. The tubercle is somewhat large and abruptly pointed. The vertex is narrow, approximately two times as wide as the ocellar triangle. The antenna is black.
;Thorax
The thorax is shining to subshining black and the pile is white or pale yellow. The longest scutellar pile is approximately equal in length to the arista, while other thoracic pile is half as long.
;Abdomen
For male specimens, the abdomen is oval, with extensive orange areas. Segment 2 usually has only the anterior and lateral edges black, sometimes with a median black line. Segment 3 has only posterolateral edges black, while segment 4 usually has a basal half that is black, occasionally with a median black line that divides the orange anterior half of the segment into two large spots. Segment 5 is dark and unmarked. The surstylus has a poorly developed basal processexternal images
For female specimens, the abdomen is broadly oval, with orange areas similar to males. Segment 2 usually has all edges black, sometimes with a median black line. Segment 3 has a complete posterior black band and sometimes also a median black band that divides the orange area into two spots. Segment 4 usually has a basal half that is black, often with a median black line that divides the orange anterior half of the segment into two large spots. Segment 5 has anterior orange spots. ;Wings The wing is darkened, entirely microtrichose.
;Legs
The legs are mostly dark, with broad apices of femora and bases of tibiae pale. The fore femur has short, stiff black setae spaced irregularly on the anteroventral and posteroventral surface. The first fore tarsomere has a large, anterior triangular process on the apical half. The first 4 tarsomeres of the mid leg are strongly flattened, each with a broad, apically rounded process which are progressively shorter from the first to third tarsomereExternal images
determination
Determination is a positive emotional feeling that promotes persevering towards a difficult goal in spite of obstacles. Determination occurs prior to goal attainment and serves to motivate behavior that will help achieve one's goal.
Empirical ...
.
Distribution
Palearctic
The Palearctic or Palaearctic is a biogeographic realm of the Earth, the largest of eight. Confined almost entirely to the Eastern Hemisphere, it stretches across Europe and Asia, north of the foothills of the Himalayas, and North Africa.
Th ...
: Fennoscandia south to France and the Alps, Ireland east through Northern Europe and Central Europe into European Russia then across Siberia and the Russian Far East to the Pacific coast. Nearctic
The Nearctic realm is one of the eight biogeographic realms constituting the Earth's land surface.
The Nearctic realm covers most of North America, including Greenland, Central Florida, and the highlands of Mexico. The parts of North America ...
: Alaska to Quebec and south to Colorado.Peck, L.V. (1988). "Syrphidae". In: Soos, A. & Papp, L. (eds.). ''Catalogue of Palaearctic Diptera'' 8: 11-230. Akad. Kiado, Budapest.
Biology
Habitat: humid grassland subject to flooding, marsh, fen, edges of raised bogs. Flies May to September. Larva have not described. It flies May to August.References
{{DEFAULTSORT:Platycheirus Granditarsus Diptera of Europe Hoverflies of Europe Syrphinae Diptera of North America Hoverflies of North America Insects described in 1771 Taxa named by Johann Reinhold Forster Fauna of the Rocky Mountains