''Spilomyia longicornis'' is a species of syrphid fly, also known as a flower fly or
hoverfly
Hover flies, also called flower flies or syrphid flies, 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 ...
, in the family
Syrphidae. Although the appearance of ''S. longicornis'' is remarkably similar to a
vespid
The Vespidae are a large (nearly 5000 species), diverse, cosmopolitan family of wasps, including nearly all the known eusocial wasps (such as ''Polistes fuscatus'', ''Vespa orientalis'', and ''Vespula germanica'') and many solitary wasps. Each ...
wasp, it is a fly and cannot sting.
[Penney, H. (2001). Evolution of Imperfect Mimicry: Explaining Variation in Mimetic Fidelity among Syrphid Species. Ottawa, ON: Carleton University. https://curve.carleton.ca/system/files/etd/c3df345b-38ec-4006-8143-6698a6294f9d/etd_pdf/d4161934a9585fb98190d9a19bed4e1b/penney-evolutionofimperfectmimicryexplainingvariation.pdf] It occurs in
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, east of the
Rocky Mountains
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...
.
Description
''S. longicornis'' is typically 11–15 millimeters long.
[Species Spilomyia longicornis. (n.d.). Retrieved October 23, 2019, from Bug Guide website: https://bugguide.net/node/view/5906] ''S. longicornis'' has a black body with yellow markings and stripes on its abdomen.
Its wings are mostly clear with a dark tinge, and the anterior portion of the wings are typically darker brown in colour.
The back four legs are yellowish in colour, and the front two legs are yellow at the base and black at the ends.
They tend to rest on their back four legs and move their front two legs above their head, making them appear like antennae on the
Hymenoptera
Hymenoptera is a large order (biology), order of insects, comprising the sawfly, sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are Par ...
species that they mimic.
This Eastern Hornet Fly
''Spilomyia longicornis''
Loew, 1872 was found in Oxford, Ga on October 8th, 2022 flying around some short shrubbery.
Taxonomy
''S. longicornis'' flies are part of the
Syrphidae family, which is of the order
Diptera
Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced ...
. The hoverfly family is one of the most diverse in the Diptera order.
[Katzourakis, A. , Purvis, A. , Azmeh, S. , Rotheray, G. and Gilbert, F. (2001), "Macroevolution of hoverflies (Diptera: Syrphidae): the effect of using higher‐level taxa in studies of biodiversity, and correlates of species richness". ''Journal of Evolutionary Biology'', 14: 219–227. doi:10.1046/j.1420-9101.2001.00278.x] There are at least 200 genera and 5000 species included in this family.
Distribution and habitat
''S. longicornis'' is widespread in eastern
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
.
[Spilomyia longicornis Loew, 1872. (n.d.). Retrieved October 27, 2019, from Discover Life website: https://www.discoverlife.org/mp/20q?search=Spilomyia+longicornis] These flies can be found near and around flowers that produce pollen and nectar, which they feed on.
Also, rotting trees are an important environmental component of their habitat.
''S. longicornis'' larvae are typically found in rot holes, or rotting cavities found in live trees, and develop there.
[Sommaggio, D. (1999). "Syrphidae: can they be used as environmental bioindicators?" ''Agriculture, Ecosystems & Environment'', 74(1–3), 343–356. https://doi.org/10.1016/S0167-8809(99)00042-0] Almost all types of trees can develop rot holes, but they are more common for certain types of trees than others.
The rot holes provide a food source and protection for the larvae.
Thus, these damp environments are ideal for larval development.
Adult ''S. longicornis'' flies are most often found hovering over flowers that produce large amounts of pollen and nectar, the adults' food source.
Life history
''S. longicornis'' larvae are found in rot holes in rotting trees.,
while adults spend the majority of their time around flowers to get pollen and nectar for food and for mating.
Females need pollen for reproductive development.
Only adult ''S. longicornis'' flies eat the pollen and nectar from flowers.
[Branquart, E., & Hemptinne, J.-L. (2000). "Selectivity in the exploitation of floral resources by hoverflies (Diptera: Syrphinae)". ''Ecography'', 23, 732–742. Retrieved from
https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1600-0587.2000.tb00316.x] Pollen has a high content of nitrogenous nutrients. Because of this, females are able to use the nutrients from pollen to develop their reproductive tissues.
These nutrients, which are not consumed by ''S. longicornis'' flies until adulthood, are important for
vitellogenesis
Vitellogenesis is the process of yolk protein formation in the oocytes of non mammalian vertebrates during sexual maturation. The term ''vitellogenesis'' comes from the Latin ''vitellus'' ("egg yolk"). Yolk proteins, such as Lipovitellin and Phosv ...
, also known as yolk deposition.
They also consume nectar from flowers and use that energy for their hovering behavior.
Mating
''S. longicornis'' males have been directly observed mate-seeking near flowers.
[C.T. Maier, G.P. Waldbauer (1979) "Dual mate-seeking strategies in male syrphid flies (Diptera: Syrphidae)". ''Annals of the Entomological Society of America'' 72: 54–61 https://doi.org/10.1093/aesa/72.1.54]
Mimicry
Most
Syrphidae flies mimic
Hymenoptera
Hymenoptera is a large order (biology), order of insects, comprising the sawfly, sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are Par ...
species.
[Waldbauer, G. P. (n.d.). Mimicry of Hymenopteran Antennae by Syrphidae. Department of Entomology, University of Illinois.] ''S. longicornis'' mimics
vespid
The Vespidae are a large (nearly 5000 species), diverse, cosmopolitan family of wasps, including nearly all the known eusocial wasps (such as ''Polistes fuscatus'', ''Vespa orientalis'', and ''Vespula germanica'') and many solitary wasps. Each ...
species including introduced species such as ''
Vespula vulgaris
''Vespula vulgaris'', known as the Common wasp, is a species found in regions that include the United Kingdom, Ireland, Germany, India, China, New Zealand and Australia. It is sometimes known in English as the European wasp, but the same name is ...
''.
''S. longicornis'' flies mimic vespid wasps in three main ways: physically, behaviorally, and auditorily. Just like vespid wasps, the anterior portion of the wings of ''S. longicornis'' flies are a darker brown color than the rest of the wing.
Their abdomen is yellow with black stripes, and the thorax and head are similarly colored. Behaviorally, ''S. longicornis'' flies mimic the way common wasps move their antennae. By resting on their back four legs and placing and moving their two front black legs above their head, they more closely resemble wasps.
[Rashed, A., & Sherratt, T. N. (2006). "Mimicry in hoverflies (Diptera: Syrphidae): a field test of the competitive mimicry hypothesis". ''Behavioral Ecology'', 18(2), 337–344. https://doi.org/10.1093/beheco/arl089] When threatened, ''S. longicornis'' bend their abdomen in a similar fashion to wasps who are stinging a predator. They may also move their abdomen up and down when they are on a flower, which is a mimic of wasp abdomen expansion. Finally, it has been documented that ''S. longicornis'' flies, when threatened, produce a different buzzing sound than normal.
[A. Rashed, M.I. Khan, J.W. Dawson, J.E. Yack, T.N. Sherratt, "Do hoverflies (Diptera: Syrphidae) sound like the Hymenoptera they morphologically resemble?" ''Behavioral Ecology'', Volume 20, Issue 2, March–April 2009, Pages 396–402, https://doi.org/10.1093/beheco/arn148] While wasps do not necessarily produce a different sound upon attack, the sound ''S. longicornis'' makes when threatened seems to be of a frequency similar to some hymenopteran species.
This strategy may have evolved because the visual and behavioral mimicry may not always work.
External links
Diptera.infoNCBI Taxonomy Browser, ''Spilomyia longicornis''*
References
{{Use dmy dates, date=February 2018
Eristalinae