---
title: "Western Yellowjacket"
description: "Vespula pensylvanica — Insects & spiders. Vespula pensylvanica, the western yellowjacket (western yellow jacket), is a Nearctic species of wasp in the genus Vespula."
canonical: https://animalchecklist.com/animal/western-yellowjacket
last_updated: 2026-09-20
---

# Western Yellowjacket

> Vespula pensylvanica — Insects & spiders. Vespula pensylvanica, the western yellowjacket (western yellow jacket), is a Nearctic species of wasp in the genus Vespula.

- Scientific name: *Vespula pensylvanica*
- Category: `insects` (Insects & spiders)
- Habitats: unknown
- iNaturalist observations: 21044
- Wikidata: [Q3122495](https://www.wikidata.org/wiki/Q3122495)
- iNaturalist taxon: [61355](https://www.inaturalist.org/taxa/61355)

## Names

- en: Western Yellowjacket
- es: Avispa chaqueta amarilla occidental
- fr: Guêpe de l'ouest

## Countries with the most observations

US (15664), CA (2911), MX (96)

## Summary

Vespula pensylvanica, the western yellowjacket (western yellow jacket), is a Nearctic species of wasp in the genus Vespula. It is native to regions of North America, largely in areas with northern temperate climates. Its reproductive behavior is constrained by cold weather, which successfully reduces the number of western yellowjackets in cold months. However, in the absence of cold weather, this wasp's population can explode. The western yellowjacket has become particularly invasive in the Hawaiian Islands, resulting in their label as a major pest.

Text: Wikipedia (en), CC BY-SA 4.0 — https://en.wikipedia.org/wiki/Vespula_pensylvanica

## Photo

![Western Yellowjacket](https://animalchecklist.com/img/animals/western-yellowjacket/medium.jpg)

Photo: Jesse Rorabaugh · CC0 · inaturalist — https://www.inaturalist.org/observations/3330434

## Machine access

`GET https://animalchecklist.com/api/v1/animals/western-yellowjacket?lang=en` — see [openapi.json](https://animalchecklist.com/openapi.json).