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Species Vespula pensylvanica - Western Yellowjacket

Yellow jacket - Vespula pensylvanica - female  vespula - Vespula pensylvanica - male Vespula atropilosa? - Vespula pensylvanica - female Yellow Black Wasp - Vespula pensylvanica Vespula? - Vespula pensylvanica Hymenoptera - Vespula pensylvanica - female Vespula wasp March 27 2023 - Vespula pensylvanica - female Vesipidae - Vespula pensylvanica - female
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Hymenoptera (Ants, Bees, Wasps and Sawflies)
No Taxon (Aculeata - Ants, Bees and Stinging Wasps)
Superfamily Vespoidea
Family Vespidae
Subfamily Vespinae (Hornets and Yellowjackets)
Genus Vespula (Ground Yellowjackets)
Species pensylvanica (Western Yellowjacket)
Explanation of Names
Vespula pensylvanica (de Saussure 1857)
Forewing: workers 8.5–10.5 mm, ♀ 12.5–14.5 mm, ♂ 12.5–14.0 mm(1)
One of 2 species with a complete loop around the eye (may be absent in males), the other being V. sulphurea.

Queen (♀♀) Worker (♀) Male (♂)
w NA (BC-CA to MB-WI-TX) to Mexico; adventive in ON, HI(1)
Life Cycle
Nest entrance • Nest • Prepupae, pupae and adults
Vespula pensylvanica was originally described by Henri Louis Frédéric de Saussure in 1857 from a lost or destroyed holotype as Vespa pensylvanica (Carpenter & Kojima, 1997; Jacobson, 1978; Kimsey & Carpenter, 2012). The original collection location is unknown despite existence of the 1853-1857 publications of de Saussure’s Vespidae research, only half of which have been translated into English (de Saussure, 1853-7). A female lectotype (queen) was established from a collection in New Mexico from an unknown source (labeled by I. H. H. Yarrow in 1970) and is currently maintained in the Natural History Museum in Geneva, Switzerland (Carpenter & Kojima, 1997; Jacobson, 1978; Kimsey & Carpenter, 2012). In 1874 Cresson described Vpl. pennsylvanica as Vespa occidentalis (female lectotype collected in New Mexico by Mr. Henshaw and placed in at the Academy of Natural Sciences Philadelphia, United States) (Carpenter & Kojima, 1997; Jacobson, 1978; Kimsey & Carpenter, 2012). Vsp. occidentalis was later recognized as the same species as Vpl. pensylvanica [junior synonym recognized by Buysson in 1905] and a junior primary homonym of Vespa occidentalis (Oliver, 1972) (Carpenter & Kojima, 1997; Jacobson, 1978; Kimsey & Carpenter, 2012). Later, H.W. Lewis (1897) proclaimed that de Saussure’s observations of Vespula pensylvanica (Lewis misspelled the species epithet as “pennsylvanica” likely due to the misspelling from Dalla Torre’s 1894 publication regarding the distribution of the species in North America) were incorrect and that it was the same species as Vespula germanica (Fabricus 1793) as communicated by “M. de Saussure” (perhaps Henri de Saussure’s son, Maximilien de Saussure) (fig. 1). However, Lewis’s (1897) alteration of these identifications is not mentioned in any other known descriptions of the history of Vpl. pensylvanica, but may be in publications focused on Vpl. germanica. In 1802 Latreille began dividing species in the Vespa genera into subgenera (in the early identifications of these species Vespa was like the modern vespid subfamily Vespinae, which is divided into four eusocial wasp species [colloquially called hornets and yellow jackets]) (Carpenter & Kojima, 1997). The subgenus Vespula was not suggested until 1869 by Thomson and Ashmead (1902) accepted the Vespula subgenus as a genus, but this was not widely accepted until 1938 (Carpenter & Kojima, 1997). Therefore, well-known accounts of American vespine wasps from 1931 (Bishoff) and 1904 (Dalla Torre) considered Vespula species junior synonyms of their original Vespa genera names [Blüthgen recognized the name-bearing status of Vespula in 1938] (Carpenter & Kojima, 1997). Lastly, Bequaert (1932) also misspelled Vpl. pensylvanica’s species epithet as “pensylaniva” (Carpenter & Kojima, 1997).
Print References
Works Cited
1.Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the Northeastern Nearctic Region
Matthias Buck, Stephen A. Marshall, and David K. B. Cheung. 2008. Biological Survey of Canada [Canadian Journal of Arthropod Identification].
2.The Vespinae of North America (Vespidae, Hymenoptera)
L.S. Kimsey and J.M. Carpenter. 2012. Journal of Hymenoptera Research Vol. 28: 37–65.