Polistes

Taxonomy

Order: Hymenoptera
Family: Vespidae
Subfamily: Polistinae
Tribe: Polistini
Genus: Polistes Latreille, 1802
Common names: polistine wasps, umbrella wasps, paper wasps

Background

The genus Polistes occurs worldwide. This is the most common group of paper wasps in the subfamily Polistinae in North America. They are semisocial wasps with a queen and workers in each nest. The name umbrella wasp refers to the shape of their nests, which have exposed cells on one side and a petiole on the other, without a paper envelope.

How to separate from Asian giant hornet

  • Most paper wasps are significantly smaller and less "robust" than Asian giant hornets
  • They have a well-defined wasp waist that separates them from many other types of wasps and hornets

Distribution

There are 24 species of Polistes in the Nearctic region, and 90 in the New World.

The distribution of Polistes sp. by GBIF: https://www.gbif.org/species/1310500

Diagnostic characteristics

To identify the family Vespidae:

  • They have a distinct ‘U-shape’ to the posterior margin of the pronotum viewed from above
  • The forewings are folded in half longitudinally their entire length

To identify to genus Polistes:

  • Their bodies are more slender than yellowjackets
  • When they fly their long legs dangling below their bodies
  • Their legs are more slender and with less extensive yellow markings than in yellowjackets
  • Their nests are shaped like an umbrella, with the cells exposed on the bottom or side, and no paper envelope enclosing the nest.
  • Males have apically curled antennae and yellow faces, except male P. annularis have red faces like the females.

Diversity

Polistes is the largest genus in the family Vespidae, with over 300 species and subspecies.

Host/prey associations

All species of Polistes are predatory, and feed caterpillars and other insects to their larvae. Adults feed on sugary materials, like nectar and juice from ripe fruit.

Nesting and general behavior

Polistes species build single-layered nests that are sometimes shaped like an umbrella, with the cells exposed and no envelope around the nest. The nests are suspended from a surface by a petiole and are constructed from a paper-like material made from a mixture of saliva and plant fibers chewed from softwood or dead twigs.

Adults fly from early spring to late fall in temperate regions, and year-round in warm regions. The nest founding (or pre-emergence) phase begins in spring where a nest is initiated by one or several related females. Eggs are laid in the cells and guarded by the foundress and assisting females, if are present. The worker phase starts in early summer. The workers emerge and take on most of the colony’s work, foraging, caring for the brood, and maintaining the nest. At this point, all of the assisting females are aggressively driven from the nest and either build their own nests or usurp another’s nest. Mature colonies contain up to 30 adult females. During the reproductive phase, males and females emerge from the nests and mate during nuptial flights. As soon as the nuptial flight happens the colony enters the intermediate phase where care for the nest and individuals decreases. Almost exclusively inseminated females gather in groups of up to 50 individuals and seek a protected site to overwinter. Polistes annularis males may also overwinter (Wikipedia 2021).

Known invasives

The European paper wasp, Polistes dominula, was introduced into the U.S. in about 1981 and has spread quickly throughout most of the country, in most cases replacing native species within a few years. There are also multiple introduced species of Polistes that are pests in New Zealand.

<p><em>Polistes dominula</em>; photo by Judy Gallagher, Flickr</p>
<p><em>Polistes dorsalis</em>; photo by Judy Gallagher, Flickr</p>
<p><em>Polistes dominula</em>; photo by u278, Flickr</p>
<p><em>Polistes dominula</em>; photo by Judy Gallagher, Flickr</p>
<p><em>Polistes dorsalis</em>; photo by Judy Gallagher, Flickr</p>
<p><em>Polistes fuscatus</em>; photo by Judy Gallagher, Flickr</p>
<p><em>Polistes fuscatus</em>; photo by Judy Gallagher, Flickr</p>
<p><em>Polistes fuscatus</em>; photo by Judy Gallagher, Flickr</p>
<p><em>Polistes commanchus</em>, lateral view; photo by Brennen Dyer, UC Davis</p>
<p><em>Polistes dorsalis</em>, lateral view; photo by Brennen Dyer, UC Davis</p>
<p><em>Polistes fuscatus</em>, latera viewl; photo by Brennen Dyer, UC Davis</p>
<p><em>Polistes aurifer</em>, dorsal view; photo by Hanna Royals, USDA APHIS PPQ ITP</p>
<p><em>Polistes dominula</em>, dorsal view; photo by Todd Gilligan, USDA APHIS PPQ ITP</p>
<p><em>Polistes dominula</em>, dorsal view; photo by Todd Gilligan, USDA APHIS PPQ ITP</p>
<p><em>Polistes dominula</em>, lateral view; photo by Todd Gilligan, USDA APHIS PPQ ITP</p>
<p><em>Polistes dominula</em>, dorsal view; photo by Hanna Royals, USDA APHIS PPQ ITP</p>
<p><em>Polistes fuscatus</em>, dorsal view; photo by Hanna Royals, USDA APHIS PPQ ITP</p>
<p><em>Polistes fuscatus</em>, lateral view; photo by Todd Gilligan, USDA APHIS PPQ ITP</p>
<p><em>Polistes</em> spp. (left) compared to <em>Vespa mandarinia</em> (right) dorsal view; photos by Hanna Royals and Todd Gilligan, USDA APHIS PPQ ITP</p>