Vespa dybowskii

Taxonomy

Order: Hymenoptera
Family: Vespidae Laicharting, 1781
Subfamily: Vespinae Laicharting, 1781
Genus: Vespa Linnaeus, 1758
Species: Vespa dybowskii André, 1884
Common names: black hornet, Dybowski’s hornet

Background

Vespa dybowskii occurs in central East Asia where it is a facultative, temporary social parasite of V. crabro and V. simillima. The V. dybowskii queens take over the nests and use host workers to raise their own brood (Matsuura and Yamane 1984; Smith-Pardo et al. 2020).

Distribution

Vespa dybowskii is native to Myanmar, Tibet, Zhejiang, Siberia, Primorsky, Korea, and Japan (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:

• metasomal segments 3–5 mostly dark brown or black, some segments with narrow distaldistal:
  part of a segment that is furthest from the point of attachment to the body
  yellow band
• vertex vertex:
  the area between the ocelli and the back of the head
  reddish to dark brown (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.

Biology/Life cycle

The prey habits of V. dybowskii are not well known, but it has been observed eating dragonflies, a tettigoniid, and even frog muscles (Matsuura and Yamane 1984)(Matsuura and Yamane 1984):
Matsuura M amp; S Yamane. 1984. Biology of the Vespine Wasps. Springer-Verlag: New York..

Nesting habits of V. dybowskii are similar to those of V. crabro. Vespa dybowskii has a worker caste and usually builds its own nest in attics, gaps in wooden walls, and tree hollows. It has also been known to usurp the nests of V. crabro and V. simillima with recently emerged workers and will take over the nest by killing the host queen. The V. dybowskii queen is still able to produce her own workers so that the invaded colony can persist even after the host workers die off, although the colony is usually smaller than that of the host species (Matsuura and Yamane 1984)(Matsuura and Yamane 1984):
Matsuura M amp; S Yamane. 1984. Biology of the Vespine Wasps. Springer-Verlag: New York.. These colonies are annual.

May be confused with

Vespa crabro

• V. crabro males with hairs on the apexapex:
  end of any structure furthest from the head
  of the aedeagus
• V. crabro females usually with broad yellow apicalapical:
  near or at the apex or end of any structure
  bands on some or all of the second, third, fourth, and fifth gastral terga; if the bands are narrow, vertexvertex:
  the area between the ocelli and the back of the head
  is yellow or orange-yellow (Archer 2015)(Archer 2015):
  Bequaert J. 1936. The common Oriental hornets, Vespa tropica and Vespa affinis , and their color forms. Treubia 15 (4): 329ndash;351.

Vespa fumida

• V. fumida clypeusclypeus:
  sutures
  strongly bulging medially, and strongly convexconvex:
  curved outward
  in side view. In V. dybowskii clypeusclypeus:
  sutures
  is not bulging medially, and flat or gently curved in side view (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

none