''Eumerus strigatus '', (Fallén, 1817), the Onion Bulb Fly , is a fairly common species of
syrphid fly observed acoss Europe. Also found in north-central North America and other scattered locations as an introduced species from infested bulbs. Syrphid flies are also known as Hover Flies or Flower Flies because the adults are frequently found hovering around flowers from which they feed on
nectar and
pollen. The larvae feed on various bulbs.
.
Description
External imagesFor terms, see:
Morphology of Diptera
Dipteran morphology differs in some significant ways from the broader morphology of insects. The Diptera is a very large and diverse order of mostly small to medium-sized insects. They have prominent compound eyes on a mobile head, and (at most) ...
.
Wing length: .
Stigma are yellowish or light brown. Femora 3 is simple. Tergites are blackish, absolutely without reddish-brown markings. Male ocelli are in an equilateral triangle. Male genitalia figured by Van Veen (2004).
The Larva is described and figured by Heiss (1938) .
Distribution
Palaearctic
The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa.
The realm consists of several bioregions: the Euro-Sibe ...
, Fennoscandia South to Iberia and the Mediterranean basin, Ireland east through Europe into Turkey and Russia. Also, from the Urals to the Pacific coast (Sakhalin) and Japan. Introduced to the
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 ...
and Australia and New Zealand.
Biology
The habitat is wetlands, deciduous woodland, open ground, seasonally-flooded grassland,
and open, dry unimproved pasture, including dune grassland. Also in horticultural land and suburban gardens.
In dry grassland often settles on the ground, on stones etc. Flowers visited include umbellifers, ''Allium ursinum'', ''Convolvulus'', ''Eschscholzia californica'', ''Euphorbia'', ''Fragaria'', ''Leontodon'', ''Papaver'', ''Potentilla erecta'', ''Ranunculus'', ''Sonchus arvensis'', ''Taraxacum''. The flight period is May to September. A bulb feeder. It is a minor pest of Liliaceae, parsnip, carrot, potato, asparagus, artichoke roots (''Cynara scolymus'').
[de Buck, N. (1990). "Bloembezoek en bestuivingsecologie van Zweefvliegen (Diptera, Syrphidae) in het bijzonder voor België". ''Doc.Trav.'' IRSNB, no. 60, pp 1-167.]
References
{{Taxonbar, from=Q9364443
Diptera of Europe
Eristalinae
Eumerini
Insects described in 1817