Stromboceridea

Taxonomy

Family: Tenthredinidae
Family common name: common sawflies
Subfamily: Selandriinae
Tribe: Aneugmenini
Genus: Stromboceridea Rohwer, 1911
Subgenera: none

Background

The Tenthredinidae are the most species-rich family and are found throughout the world, in all continents but Antarctica. They are known as the common sawflies. They can generally be recognized by a cylindrical body and long, segmented antennaeantenna:
the sensory organ emerging from the front of the head, usually between the compound eyes and above the clypeus; includes the flagellum, scape and pedicel
. Otherwise, they come in a variety of colors, sizes, and forms (Goulet 1992Goulet 1992:
Goulet H. 1992. The genera and subgenera of the sawflies of Canada and Alaska: Hymenoptera. Symphyta. The insects and arachnids of Canada. Part 20. Agriculture Canada Publication.
).

Sawflies in the Selandriinae subfamily are relatively small and slender. The range of Selandriinae is worldwide; it occurs on all continents except Antarctica (Goulet 1992Goulet 1992:
Goulet H. 1992. The genera and subgenera of the sawflies of Canada and Alaska: Hymenoptera. Symphyta. The insects and arachnids of Canada. Part 20. Agriculture Canada Publication.
). It is the most common and diverse group of tenthredinids in tropical regions, particularly in Central America, South America, and Southeast Asia (Smith 1969eSmith 1969e:
Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
). Selandriinae contains the only known sawflies that feed on non-vascular plants, specifically ferns (Smith et al. 2013Smith et al. 2013:
Smith DR, Janzen DH and Hallwachs W. 2013. Food plants and life histories of sawflies of the families Argidae and Tenthredinidae (Hymenoptera) in Costa Rica, a supplement. Journal of Hymenoptera Research 35: 17-31. https://doi.org/10.3897/JHR.35.5496
). The subfamily can be distinguished from other subfamilies by wing venationvenation:
the network of veins on a wing
(Goulet 1992Goulet 1992:
Goulet H. 1992. The genera and subgenera of the sawflies of Canada and Alaska: Hymenoptera. Symphyta. The insects and arachnids of Canada. Part 20. Agriculture Canada Publication.
).

Stromboceridea is monotypicmonotypic:
describes having only one representative; ex. a genus that includes only one species
in the NearcticNearctic:
describing the region of the Northern Hemisphere that includes North America south through northern Mexico
region. Stromboceridea nigricans is a southwestern species about 8 mm in length and mostly black with minimal areas of white on the legs and pronotumpronotum:
the anterodorsal part of the thorax, often situated posterior to the head
(Smith 1969eSmith 1969e:
Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
).

Diversity

There are 17 described extantextant:
in existence; opposite of extinct
species worldwide. Fourteen species occur in North America (Smith 1995Smith 1995:
Smith DR. 1995. The sawflies and woodwasps. In: Hanson PE and Gauld ID, eds. The Hymenoptera of Costa Rica. Oxford University Press. Pp. 157-177.
, Taeger et al. 2010Taeger et al. 2010:
Taeger A, Blank SM, and Liston AD. 2010. World Catalog of Symphyta (Hymenoptera). Zootaxa 2580: 1-1064.
).

Diagnostic characteristics

Subfamily characters

  • fore wing fore wing:
    the anterior wing of each pair of wings; usually the largest wing of the pair
    vein Rs+M curved near intersection with veinvein:
    a tube-like, often darkened, structure on the wings
    Sc+R (Smith 1969eSmith 1969e:
    Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
    )
  • fore wing fore wing:
    the anterior wing of each pair of wings; usually the largest wing of the pair
    veins M and m-cu about parallel (Smith 1969eSmith 1969e:
    Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
    )
  • fore wing fore wing:
    the anterior wing of each pair of wings; usually the largest wing of the pair
    vein 2r-m present (Goulet 1992Goulet 1992:
    Goulet H. 1992. The genera and subgenera of the sawflies of Canada and Alaska: Hymenoptera. Symphyta. The insects and arachnids of Canada. Part 20. Agriculture Canada Publication.
    )

Genus characters

  • clypeus clypeus:
    sclerotized area on the front of the head located between the antennal insertions and labrum
    margin straight or shallowly emarginated (Smith 1969eSmith 1969e:
    Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
    )
  • clypeus clypeus:
    sclerotized area on the front of the head located between the antennal insertions and labrum
    distinctly convexconvex:
    describing an outward curving surface, opposite of concave
    in laterallateral:
    of or towards the side of the body
    view (Smith 1969eSmith 1969e:
    Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
    )
  • malar space malar space:
    the minimum distance between the base of the mandible and the ventral margin of the compound eye
    extremely narrow (Smith 1969eSmith 1969e:
    Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
    )
  • occipital ridge present (Smith 1969eSmith 1969e:
    Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
    )
  • pedicel pedicel:
    the second antennal segment, between the scape and flagellum
    longer than wide (Smith 1969eSmith 1969e:
    Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
    )
  • fore wing fore wing:
    the anterior wing of each pair of wings; usually the largest wing of the pair
    vein M meeting Sc+R at intersection of Rs+M and Sc+R (Smith 1969eSmith 1969e:
    Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
    )
  • fore wing fore wing:
    the anterior wing of each pair of wings; usually the largest wing of the pair
    anal crossveinanal crossvein:
    a crossvein that goes through the center of the basal anal cell
    absent (Smith 1969eSmith 1969e:
    Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
    )
  • hind wing hind wing:
    the posterior wing of each pair of wings
    anal cellanal cell:
    cell A of either the fore wing or hind wing
    petiole absent (Smith 1969eSmith 1969e:
    Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
    )
  • tarsal claw tarsal claw:
    sharpened appendage emerging from the apex of the tarsus
    with relatively long inner tooth and acute basalbasal:
    towards the base; closest to the body
    lobe (Smith 1969eSmith 1969e:
    Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
    )

May be confused with

Stromboceridea can be confused with similar species in the subfamily Selandriinae or tribe Aneugmenini. It can be distinguished from most other genera by the absence of a fore wingfore wing:
the anterior wing of each pair of wings; usually the largest wing of the pair
anal crossveinanal crossvein:
a crossvein that goes through the center of the basal anal cell
, and from closely related Eustromboceros by the tarsal clawtarsal claw:
sharpened appendage emerging from the apex of the tarsus
(Smith 1969eSmith 1969e:
Smith DR. 1969e. Nearctic Sawflies. II. Selandriinae: Adults (Hymenoptera: Tenthredinidae). Technical Bulletin, U.S. Department of Agriculture 1398: 1-48.
).

Exotic pest species of concern

none

Host associations

unknown

Life history

unknown

Distribution

World: This genus is known from North and South America (Taeger et al. 2010Taeger et al. 2010:
Taeger A, Blank SM, and Liston AD. 2010. World Catalog of Symphyta (Hymenoptera). Zootaxa 2580: 1-1064.
).

North America: The genus is most common in Mexico and Central America and is recorded throughout (Rohwer 1911Rohwer 1911:
Rohwer SA. 1911. New sawflies in the collections of the United States National Museum. Proceedings of the United States National Museum 41: 377-411.
, Smith 1971cSmith 1971c:
Smith DR. 1971c. Nearctic sawflies of the genera Neoptilia Ashmead, Schizocerella Forsius, Aprosthema Konow, and Sphacophilus Provancher (Hymenoptera: Argidae). Transactions of the American Entomological Society 97: 537-594.
, Smith 1995Smith 1995:
Smith DR. 1995. The sawflies and woodwasps. In: Hanson PE and Gauld ID, eds. The Hymenoptera of Costa Rica. Oxford University Press. Pp. 157-177.
). Only S. nigricans also occurs farther north in Arizona (Smith 2016Smith 2016:
Smith DR. 2016. Pristiphora subbifida (Thomson) (Hymenoptera: Tenthredinidae), a Palearctic Sawfly new to North America. Proceedings of the Entomological Society of Washington 118: 297-299. https://doi.org/10.4289/0013-8797.118.2.297
).

Map data from: GBIF.org (29 October 2019) GBIF Occurrence Download Stromboceridea and the Smithsonian National Museum of Natural History Entomology Collection (USNM)

Details about data used for maps can be found here.

  Stromboceridea nigricans  female lateral habitus; photo by Q. Baine, WSDA

Stromboceridea nigricans female lateral habitus; photo by Q. Baine, WSDA

  Stromboceridea nigricans  female dorsal habitus; photo by J. Orr, WSDA

Stromboceridea nigricans female dorsal habitus; photo by J. Orr, WSDA

  Stromboceridea nigricans  female face; photo by Q. Baine, WSDA

Stromboceridea nigricans female face; photo by Q. Baine, WSDA

  Stromboceridea nigricans  male lateral habitus; photo by J. Orr, WSDA

Stromboceridea nigricans male lateral habitus; photo by J. Orr, WSDA

  Stromboceridea nigricans  male dorsal habitus; photo by J. Orr, WSDA

Stromboceridea nigricans male dorsal habitus; photo by J. Orr, WSDA

  Stromboceridea nigricans  male face; photo by Q. Baine, WSDA

Stromboceridea nigricans male face; photo by Q. Baine, WSDA

  Stromboceridea nigricans  wings; photo by J. Orr, WSDA

Stromboceridea nigricans wings; photo by J. Orr, WSDA