Hoplocampa

Taxonomy

Family: Tenthredinidae
Family common name: common sawflies
Subfamily: Nematinae
Tribe: Nematini
Genus: Hoplocampa Hartig, 1837
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.
).

Nematinae is the second-largest subfamily of Tenthredinidae with over 1,250 species (Prous et al. 2014Prous et al. 2014:
Prous M, Blank SM, Goulet H, Heibo E, Liston A, Malm T, Nyman T, Schmidt S, Smith DR, Varing;rdal H, Viitasaari M, Vikberg V, and Taeger A. 2014. The genera of Nematinae (Hymenoptera, Tenthredinidae). Journal of Hymenoptera Research 40: 1-69. " target="_blank">https://doi.org/10.3897/JHR.40.7442
). They are most diverse in northern Eurasia and North America; only a few species occur in the Southern Hemisphere. Nematinae sawflies have a variety of feeding habits including external leaf feeding, leaf mining, and gall forming, and feed on a variety of hosts (Smith 2003bSmith 2003b:
Smith DR. 2003b. A Synopsis of the sawflies (Hymenoptera: Symphyta) of America south of the United States: Tenthredinidae (Nematinae, Heterarthrinae, Tenthredininae). Transactions of the American Entomological Society 129 (1): 1-45.
).

The Nematinae have been subject to numerous revisions in recent years. As of 2021, there are no comprehensive keys to many of the North American species of Nematinae (Prous et al. 2014Prous et al. 2014:
Prous M, Blank SM, Goulet H, Heibo E, Liston A, Malm T, Nyman T, Schmidt S, Smith DR, Varing;rdal H, Viitasaari M, Vikberg V, and Taeger A. 2014. The genera of Nematinae (Hymenoptera, Tenthredinidae). Journal of Hymenoptera Research 40: 1-69. " target="_blank">https://doi.org/10.3897/JHR.40.7442
). Because of changing taxonomy and extreme variability in morphology, identifying genera and species in the Nematinae may be more challenging than in other subfamilies of Tenthredindae. For this reason, knowing the host or behaviors of a specimen can be extremely helpful for identification within this subfamily.

Hoplocampa are about 7–9 mm in length, with variable colors. They feed on developing fruits of Rosaceae, including several agricultural crops such as apple, cherry, and pear, making them an economic pest (Ross 1943cRoss 1943c:
Ross HH. 1943c. The North American sawflies of the genus Hoplocampa (Hymenoptera: Tenthredinidae) Transactions of the American Entomological Society 69: 61-92.
).

Diversity

There are 45 described species worldwide. Twenty-two species occur in North America (Taeger et al. 2018Taeger et al. 2018:
Taeger A, Liston AD, Prous M, Groll EK, Gehroldt T, and Blank SM. 2018. ECatSymmdash;Electronic World Catalog of Symphyta (Insecta, Hymenoptera). Program version 5.0 (19 Dec 2018), data version 40 (23 Sep 2018). Senckenberg Deutsches Entomologisches Institut (SDEI), Muuml;ncheberg. https://sdei.de/ecatsym/ Accessed: 28 Jan 2020.
).

A key to North American species is included in Ross 1943cRoss 1943c:
Ross HH. 1943c. The North American sawflies of the genus Hoplocampa (Hymenoptera: Tenthredinidae) Transactions of the American Entomological Society 69: 61-92.
.

Diagnostic characteristics

Subfamily characters​

  • veins M and 1m-cu convergent toward the stigmastigma:
    a section of the fore wing at the apex of vein C that is sclerotized, rounded and often darkened
    (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

  • short post-ocellar furrowfurrow:
    a groove or linear depression
    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.
    )
  • flagellomeres short; combined length of scapescape:
    the first antennal segment
    and pedicelpedicel:
    the second antennal segment, between the scape and flagellum
    at least ¾ length of, or longer than, the first flagellomereflagellomere:
    A segment of the flagellum of the antenna
    (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.
    )
  • antennae thin and thread-like (Prous et al. 2014Prous et al. 2014:
    Prous M, Blank SM, Goulet H, Heibo E, Liston A, Malm T, Nyman T, Schmidt S, Smith DR, Varing;rdal H, Viitasaari M, Vikberg V, and Taeger A. 2014. The genera of Nematinae (Hymenoptera, Tenthredinidae). Journal of Hymenoptera Research 40: 1-69. " target="_blank">https://doi.org/10.3897/JHR.40.7442
    )
  • epicnemial furrowfurrow:
    a groove or linear depression
    distinct and sharp (Prous et al. 2014Prous et al. 2014:
    Prous M, Blank SM, Goulet H, Heibo E, Liston A, Malm T, Nyman T, Schmidt S, Smith DR, Varing;rdal H, Viitasaari M, Vikberg V, and Taeger A. 2014. The genera of Nematinae (Hymenoptera, Tenthredinidae). Journal of Hymenoptera Research 40: 1-69. " target="_blank">https://doi.org/10.3897/JHR.40.7442
    )
  • fore wing fore wing:
    the anterior wing of each pair of wings; usually the largest wing of the pair
    vein 2m-cu meeting cellcell:
    1. a membranous area of the wing between veins, 2. a small cavity or closed space
    2Rs above (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.
    )
  • fore wing fore wing:
    the anterior wing of each pair of wings; usually the largest wing of the pair
    veins M and Rs+M relatively widely separated on veinvein:
    a tube-like, often darkened, structure on the wings
    R (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.
    )
  • fore wing fore wing:
    the anterior wing of each pair of wings; usually the largest wing of the pair
    vein 2r-rs 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.
    )
  • hind wing hind wing:
    the posterior wing of each pair of wings
    vein 2A+3A meeting 1A; basalbasal:
    towards the base; closest to the body
    anal cellanal cell:
    cell A of either the fore wing or hind wing
    present (Prous et al. 2014Prous et al. 2014:
    Prous M, Blank SM, Goulet H, Heibo E, Liston A, Malm T, Nyman T, Schmidt S, Smith DR, Varing;rdal H, Viitasaari M, Vikberg V, and Taeger A. 2014. The genera of Nematinae (Hymenoptera, Tenthredinidae). Journal of Hymenoptera Research 40: 1-69. " target="_blank">https://doi.org/10.3897/JHR.40.7442
    )
  • first tergitetergite:
    a sclerotized segment of the tergum
    narrow medially; membranous area posterior to tergitetergite:
    a sclerotized segment of the tergum
    1 wide (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.
    )

May be confused with

Hoplocampa may be confused with other genera in the subfamily Nematinae, particularly those with shorter 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
such as Adelomos or Caulocampus, but can be distinguished from most other genera by the wide space between fore wingfore wing:
the anterior wing of each pair of wings; usually the largest wing of the pair
veins M and Rs+M on veinvein:
a tube-like, often darkened, structure on the wings
R, the presence of 2r-rs, the length of the scapescape:
the first antennal segment
and pedicelpedicel:
the second antennal segment, between the scape and flagellum
, and the location of fore wingfore wing:
the anterior wing of each pair of wings; usually the largest wing of the pair
vein 2m-cu (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.
).

Exotic pest species of concern

Two sawflies are pests of plum in Europe. Hoplocampa minuta, the black plum sawfly, is a more significant economic pest than H. flava, the yellow plum sawfly, in most regions, appearing in greater abundance and inflicting greater damage. Both are multivoltinemultivoltine:
describing a life cycle with many generations per calendar year
(Tamošiūnas et al. 2014, Liston et al. 2019aListon et al. 2019a:
Liston AD, Prous M, and Varing;rdal H. 2019a. A review of West Palaearctic Hoplocampa species, focussing [sic] on Sweden (Hymenoptera, Tenthredinidae). Zootaxa 4615 (1): 1-45. https://doi.org/10.11646/zootaxa.4615.1.1
). Because of the habit of feeding inside of the fruit, control methods are difficult to implement (Caruso and Cera 2004Caruso and Cera 2004:
Caruso S and Cera MC. 2004. Control strategies for plum sawflies ( Hoplocampa flava , Hoplocampa minuta ) in organic farming. Integrated plant protection in stone fruit IOBC/wprs Bulletin Vol. 27 (5): 105-107.
).

Hoplocampa brevis is a pest of pear in southern regions of Europe, and occasionally feeds on apple as well (Liston et al. 2019aListon et al. 2019a:
Liston AD, Prous M, and Varing;rdal H. 2019a. A review of West Palaearctic Hoplocampa species, focussing [sic] on Sweden (Hymenoptera, Tenthredinidae). Zootaxa 4615 (1): 1-45. https://doi.org/10.11646/zootaxa.4615.1.1
).

Native or introduced pest species

Hoplocampa cookei, a native species also known as the cherry fruit sawfly, has been recorded as a pest of cherry in California (Ross 1943cRoss 1943c:
Ross HH. 1943c. The North American sawflies of the genus Hoplocampa (Hymenoptera: Tenthredinidae) Transactions of the American Entomological Society 69: 61-92.
).

The introduced H. testudinea, known as the apple sawfly, is a pest of apple fruit in Europe and North America (Liston et al. 2019aListon et al. 2019a:
Liston AD, Prous M, and Varing;rdal H. 2019a. A review of West Palaearctic Hoplocampa species, focussing [sic] on Sweden (Hymenoptera, Tenthredinidae). Zootaxa 4615 (1): 1-45. https://doi.org/10.11646/zootaxa.4615.1.1
). Though the species is univoltineunivoltine:
describing an insect with a life cycle of one generation per year
, the fact that one larvalarva:
the immature stage of holometabolous insects
can damage up to five or six apple fruits in its lifetime results in significant annual damage to fruit yields. Because of the protection the fruit provides, control methods for this pest are challenging (Pyenson 1943Pyenson 1943:
Pyenson L. 1943. A destructive apple sawfly new to North America. Journal of Economic Entomology 36 (2): 218-221.
).

Host associations

In North America, Hoplocampa feeds on Malus (apple), Crataegus (hawthorn), Pyrus (pear), Prunus (cherry, plum), and Amelanchier (serviceberry) (Ross 1943cRoss 1943c:
Ross HH. 1943c. The North American sawflies of the genus Hoplocampa (Hymenoptera: Tenthredinidae) Transactions of the American Entomological Society 69: 61-92.
).

Life history

Females oviposit into the calyx of a flower of the host. LarvaeLarva:
the immature stage of holometabolous insects
bore into and feed on the immature fruit, often visiting several fruits during their development. Affected fruits often cease development and fall off the plant. At maturity, the larvaelarva:
the immature stage of holometabolous insects
fall to the ground to overwinter and pupate (Ross 1943cRoss 1943c:
Ross HH. 1943c. The North American sawflies of the genus Hoplocampa (Hymenoptera: Tenthredinidae) Transactions of the American Entomological Society 69: 61-92.
).

Distribution

World: The genus is known from North America, North Africa, and throughout Europe and Asia (Liston et al. 2019aListon et al. 2019a:
Liston AD, Prous M, and Varing;rdal H. 2019a. A review of West Palaearctic Hoplocampa species, focussing [sic] on Sweden (Hymenoptera, Tenthredinidae). Zootaxa 4615 (1): 1-45. https://doi.org/10.11646/zootaxa.4615.1.1
).

North America: Hoplocampa occurs throughout the United States and Canada (Ross 1943cRoss 1943c:
Ross HH. 1943c. The North American sawflies of the genus Hoplocampa (Hymenoptera: Tenthredinidae) Transactions of the American Entomological Society 69: 61-92.
). Hoplocampa testudinea was introduced from Europe and first discovered on the East Coast in 1939 in New York (Pyenson 1943Pyenson 1943:
Pyenson L. 1943. A destructive apple sawfly new to North America. Journal of Economic Entomology 36 (2): 218-221.
), and on the West Coast in 1940 in British Columbia (Downes and Andison 1942Downes and Andison 1942:
Downes W and Andison H. 1942. The apple sawfly Hoplocampa testudinea Klug. on Vancouver Island, British Columbia. Journal of the Entomological Society of British Columbia 39: 13-16.
). It has since become established in the northeastern United States and southeastern Canada (GBIF).

Map data from: GBIF.org (29 October 2019) GBIF Occurrence Download Hoplocampa

Details about data used for maps can be found here.

  Hoplocampa bioculata  female lateral habitus; photo by J. Orr, WSDA

Hoplocampa bioculata female lateral habitus; photo by J. Orr, WSDA

  Hoplocampa bioculata  female face; photo by Q. Baine, WSDA

Hoplocampa bioculata female face; photo by Q. Baine, WSDA

  Hoplocampa pallipes  male lateral habitus; photo by J. Orr, WSDA

Hoplocampa pallipes male lateral habitus; photo by J. Orr, WSDA

  Hoplocampa pallipes  male face; photo by Q. Baine, WSDA

Hoplocampa pallipes male face; photo by Q. Baine, WSDA

  Hoplocampa alpestris  fore wing; photo by J. Orr, WSDA

Hoplocampa alpestris fore wing; photo by J. Orr, WSDA