Taxonomy
Order: Hymenoptera
Family: Vespidae Laicharting, 1781
Subfamily: Vespinae Laicharting, 1781
Genus: Vespa Linnaeus, 1758
Species: Vespa simillima Smith, 1868
Common names: yellow hornet
Background
Vespa simillima is native to eastern Asia (Archer 1994)(Archer 1994):
Archer ME. 1994. A phylogenetic study of the species of the genus Vespa . Insect Systematics and Evolution 24: 469ndash;478. doi: 10.1163/187631293X00226. It is one of the smaller species of Vespa, ranging from 0.7–0.9 in. (17–23 mm) long. Vespa simillima is the only species of Vespa to build nests in both open and enclosed areas above and below ground (Matsuura 1991)(Matsuura 1991):
Matsuura M. 1991. Vespa and Provespa . The Social Biology of Wasps pp. 232ndash;262.. The Vespa species V. auraria, V. bicolor, V. simillima, V. velutina, and V. vivax are considered part of the V. bicolor group.
Distribution
Vespa simillima is native to Liaoning, China, southwestern Russia, Korea, and Japan. It has been introduced into British Columbia and Taiwan but is not established in either region (Smith-Pardo et al. 2020)(Smith-Pardo et al. 2020):
Smith-Pardo A., JM Carpenter amp; LS Kimsey. 2020. The diversity of hornets in the genus Vespa , their importance and interceptions in the United States. Insect Systematics and Diversity 4 (3): 1ndash;27..
Diagnostic characteristics
To identify the genus:
- both pronotal and pretegular carinae present
- head vertexvertex:
the area between the ocelli and the back of the head
with the distance from posterior ocellusocellus:
single facet light reception organs; on the top of the adult head
to the posterior margin of vertexvertex:
the area between the ocelli and the back of the head
more than twice the distance between the posterior ocelliocelli:
single facet light reception organs; on the top of the adult head
and the compound eye
- basal basal:
originating at the foundation of a structure
metasomal segment anteriorly rounded
- forewing forewing:
the front wing attached to the middle thoracic segment
prestigma three times or more as long as the pterostigma (Smith-Pardo et al. 2020)(Smith-Pardo et al. 2020):
Smith-Pardo A., JM Carpenter amp; LS Kimsey. 2020. The diversity of hornets in the genus Vespa , their importance and interceptions in the United States. Insect Systematics and Diversity 4 (3): 1ndash;27.
To identify the species:
- clypeal punctation uniformly distributed (Smith-Pardo et al. 2020)(Smith-Pardo et al. 2020):
Smith-Pardo A., JM Carpenter amp; LS Kimsey. 2020. The diversity of hornets in the genus Vespa , their importance and interceptions in the United States. Insect Systematics and Diversity 4 (3): 1ndash;27.
- metasomal tergumtergum:
the segments on the top side of the abdomen, often abbreviated when referring to a speciifc segment, such as T1, T2, etc.
3 with transverse basalbasal:
originating at the foundation of a structure
black bandband:
usually referring to bands of hair or bands of color that traverse across an abdominal segment
simple, barely undulating (Kimsey and Carpenter 2012)(Kimsey and Carpenter 2012):
Kimsey LS amp; JM Carpenter. 2012. The Vespinae of North America. Journal of Hymenoptera Research 28: 37ndash;65. Doi.org/10.3897/jhr.28.3514.
- female clypeal punctures medially, shallow, separated by 1 puncture diameter or more
- male metasomal sternasterna:
the plates on the underside of the abdomen, often abbreviated when referring to a specific segment, like S1, S2, etc.
6 and 7 with apicomedial margin deeply emarginate
Biology/Life cycle
Vespa simillima builds relatively small nests with a few hundred cells. Nests are built in cavities in the ground and in sheltered above ground sites, including wall voids, attics, and tree hollows. They prey on a diversity of insects. Vespa simillima nests are sometimes parasitized by the black hornet, Vespa dybowskii (Matsuura and Yamane 1984)(Matsuura and Yamane 1984):
Matsuura M amp; S Yamane. 1984. Biology of the Vespine Wasps. Springer-Verlag: New York..
Vespa simillima is considered a long cycle species (about 7 months) when compared to congeners. Colonies of this species are annual. Queens first appear in early to late April and nests are founded in late April to early May. Males and new queens continue to be produced for one to two months with colony demise occurring around October. V. simillima queens overwinter in the soil or in rotten wood where she digs a cellcell:
a portion of wing membrane enclosed by wing veins
1.5–2.5 (4–6 cm) in diameter (Matsuura and Yamane 1984)(Matsuura and Yamane 1984):
Matsuura M amp; S Yamane. 1984. Biology of the Vespine Wasps. Springer-Verlag: New York..
This species will seek tree sap and nectar as a source of carbohydrates but does not do so as frequently as other species of Vespa. For protein, V. simillima predates on a wide range of insects and spiders and is considered a generalist (Matsuura and Yamane 1984)(Matsuura and Yamane 1984):
Matsuura M amp; S Yamane. 1984. Biology of the Vespine Wasps. Springer-Verlag: New York..
May be confused with
Vespa affinis
- V. affinis has the ventralventral:
the underside of an insect, or segment of an insect
metapleural punctures well-defined and nearly contiguous. In V. simillima ventralventral:
the underside of an insect, or segment of an insect
metapleural punctures shallow and separated by 1 puncture diameter or more (Kimsey and Carpenter 2012)(Kimsey and Carpenter 2012):
Kimsey LS amp; JM Carpenter. 2012. The Vespinae of North America. Journal of Hymenoptera Research 28: 37ndash;65. Doi.org/10.3897/jhr.28.3514.
Vespa bicolor
- V. bicolor scutellumscutellum:
shield shaped plate behind scutum
and metanotum entirely or largely yellow
- V. bicolor vertexvertex:
the area between the ocelli and the back of the head
black (Archer 1994)(Archer 1994):
Archer ME. 1994. A phylogenetic study of the species of the genus Vespa . Insect Systematics and Evolution 24: 469ndash;478. doi: 10.1163/187631293X00226
Vespa crabro
- V. crabro female clypeal punctures clearly defined and contiguous or nearly so
- V. crabro male metasomal sternasterna:
the plates on the underside of the abdomen, often abbreviated when referring to a specific segment, like S1, S2, etc.
6 and 7 with apicomedial margin straight or shallowly indented (Kimsey and Carpenter 2012)(Kimsey and Carpenter 2012):
Kimsey LS amp; JM Carpenter. 2012. The Vespinae of North America. Journal of Hymenoptera Research 28: 37ndash;65. Doi.org/10.3897/jhr.28.3514.
Vespa vivax
- V. vivax clypeal punctation irregularly distributed, with impunctate areas
Vespa velutina
- V. velutina clypeal punctation irregularly distributed, with impunctate areas (Smith-Pardo et al. 2020)(Smith-Pardo et al. 2020):
Smith-Pardo A., JM Carpenter amp; LS Kimsey. 2020. The diversity of hornets in the genus Vespa , their importance and interceptions in the United States. Insect Systematics and Diversity 4 (3): 1ndash;27.
Known introductions
Vespa simillima has no known established populations outside the native range.
