Species Details

Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum Read more about this collection »

SeasonalityFlight period of adults May to November, with peak abundance August/September. IdentificationApproximately 7 to 12 mm in length, black and yellow abdomen with a yellow face. Identification to species is challenging, and specimens may easily be confused with S. ribesii, S. rectus (although their distributions do not overlap), or S. vitripennis. Cell cua1 is entirely covered with tiny hairs (i.e. trichose, see A on image), and cell bm is narrowly trichose along posterior margin (see B on image), in some but not all specimens. A fairly reliable characteristic is that the yellow bands of tergites 3 and 4 either do not quite reach the lateral margins, or only barely reach then anteriorly (see C on image, and compare to other images of Syrphus spp.). Males: The frons is either entirely yellow, or the upper half of it is dark gray and covered with a waxy, whitish powder (i.e. pruinose), with lower half of frons bright yellow. The hind femur is mostly black, with only the apical one-third to one-fifth black. Females: Similar to male, but with upper one-third of frons being a blackish colour, and the hind femur being totally yellow (Vockeroth 1992).

Scientific Name Syrphus opinator Habitat Variable, from alpine areas in B.C. to alfalfa fields in California (Schneider 1969). Seasonality Flight period of adults May to November, with peak abundance August/September. Identification
Approximately 7 to 12 mm in length, black and yellow abdomen with a yellow face. Identification to species is challenging, and specimens may easily be confused with S. ribesii, S. rectus (although their distributions…
Approximately 7 to 12 mm in length, black and yellow abdomen with a yellow face. Identification to species is challenging, and specimens may easily be confused with S. ribesii, S. rectus (although their distributions do not overlap), or S. vitripennis. Cell cua1 is entirely covered with tiny hairs (i.e. trichose, see A on image), and cell bm is narrowly trichose along posterior margin (see B on image), in some but not all specimens. A fairly reliable characteristic is that the yellow bands of tergites 3 and 4 either do not quite reach the lateral margins, or only barely reach then anteriorly (see C on image, and compare to other images of Syrphus spp.). Males: The frons is either entirely yellow, or the upper half of it is dark gray and covered with a waxy, whitish powder (i.e. pruinose), with lower half of frons bright yellow. The hind femur is mostly black, with only the apical one-third to one-fifth black. Females: Similar to male, but with upper one-third of frons being a blackish colour, and the hind femur being totally yellow (Vockeroth 1992).
Life History
Poorly known, but probably multivoltine, due to its more southerly distribution in North America. Some researchers in Oregon have looked at the potential for using S. opinator as a biocontrol agent for cabbage aphids…
Poorly known, but probably multivoltine, due to its more southerly distribution in North America. Some researchers in Oregon have looked at the potential for using S. opinator as a biocontrol agent for cabbage aphids in broccoli fields (Western Region Sustainable Agriculture Research and Education 2003). Host choice of the aphidophagous larvae is probably mostly determined by the oviposition behaviour of the females, because the dispersal capabilities of most Syrphus larvae are relatively limited (Sadeghi and Gilbert 2000a,b). Females of a related species (S. corollae) were found to oviposit in response to the sole presence of aphid honeydew (Schneider 1969), although females may use both visual as well as olfactory signals for choosing an oviposition site. Females in this genus tend to choose large or growing colonies of aphids, to ensure a plentiful food source for their offspring (Sadeghi and Gilbert 2000a). Larvae are voracious predators, and can have significant impacts on aphid populations (Western Region Sustainable Agriculture Research and Education 2003). Parasitoids are unknown, although many parasitoids of other members of the genus Syrphus have been recorded, including (amongst many families) members of the Braconidae, Chalcididae, Proctotrupidae, Encyrtidae, and Ichneumonidae (particularly the subfamily Diplazontinae)(Schneider 1969).
Conservation Not of concern. Diet Info
Larvae are aphidophagous and polyphagous, and feed on a wide range of aphid species, including the pea aphid Acyrthosiphon pisum (Schneider 1969), the cabbage aphid Brevicoryne brassicae (Western Region Sustainable…
Larvae are aphidophagous and polyphagous, and feed on a wide range of aphid species, including the pea aphid Acyrthosiphon pisum (Schneider 1969), the cabbage aphid Brevicoryne brassicae (Western Region Sustainable Agriculture Research and Education 2003), and the woolly aphid, Eriosoma lanigerum (Schneider 1969). Adults feed on the pollen and nectar of flowers.
Range Found in Western Canada (Alberta and B.C.), and south between California and Texas; Minnesota as well (Vockeroth 1992).

Citation

Page Citation for Syrphus opinator

Page Citation

"Species Details - Syrphus opinator, University of Alberta E.H. Strickland Entomological Museum." University of Alberta Museums Search Site, https://search.museums.ualberta.ca/g/2-5834. Accessed 29 Mar. 2024.

Authorship

Name Wins-Purdy, A.
Role species page author
Date 2005

References

Specimen Information

There are 23 specimens of this Species.

23 results plotted on map in 13 markers.
Note: Only records with latitude and longitude coordinates are plotted on map.

UASM53615 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, Lethbridge Collected BySalt, R. W. Date Collected1940-08-22

UASM53616 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, Lethbridge Collected BySalt, R. W. Date Collected1942-09-01

UASM53617 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, Edmonton Collected ByMorrison, F. O. Date Collected1936-10-17

UASM53618 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, Royal Oak Collected ByTreherne, R. C. Date Collected1917-05-01

UASM53619 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, Lethbridge Collected BySalt, R. W. Date Collected1930-09-20

UASM53620 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, Waterton Lakes National Park, Waterton Collected ByStrickland, E. H. Date Collected1923-07-12

UASM53621 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: British Columbia, Mount Revelstoke National Park, Mount Revelstoke Collected ByVroom, P. N. Date Collected1923-08-12

UASM53622 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: British Columbia, Mount Revelstoke National Park, Mount Revelstoke Collected ByVroom, P. N. Date Collected1923-08-12

UASM53623 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: British Columbia, Mount Revelstoke National Park, Mount Revelstoke Collected ByVroom, P. N. Date Collected1923-08-12

UASM53624 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, Waterton Lakes National Park, Waterton Collected ByStrickland, E. H. Date Collected1923-07-12

UASM53625 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, High River Date Collected1920-08-01

UASM53638 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, Banff National Park, Lake Louise Collected ByBryant, O. Date Collected1925-09-01

UASM53639 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: British Columbia, Kaslo

UASM53640 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, Banff National Park, Lake Louise Collected ByBryant, O. Date Collected1925-09-01

UASM53641 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, Banff National Park, Banff Collected ByGarrett, C. B. D. Date Collected1922-10-01

UASM53642 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, Banff National Park, Banff Collected ByGarrett, C. B. D. Date Collected1922-10-02

UASM53643 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: British Columbia, Summerland Collected BySlabyj, B. M. Date Collected1957-09-15

UASM53644 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: British Columbia, Summerland Collected BySlabyj, B. M. Date Collected1957-09-15

UASM145754 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedUnited States: California, San Francisco county, San Francisco Date Collected1965-02

UASM145755 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedUnited States: California, San Francisco county, San Francisco Date Collected1965-02

UASM145756 - Syrphus opinator

University of Alberta E.H. Strickland Entomological Museum

Place CollectedUnited States: California, San Francisco county, San Francisco Date Collected1965-03

Adult Seasonal Distribution