Hodges#4195.1

Pieris oleracea

Classification

Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Order: Lepidoptera
Superfamily: Papilionoidea
Family: Pieridae
Subfamily: Pierinae
Tribe: Pierini
Genus: Pieris
Species: oleracea

Pronunciation

How to pronounce Pieris oleracea: //ˈpaɪərɪs ˌɒləˈræsiə//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Pieris oleracea by the Smithsonian. Used under a CC0 license.

Summary

Pieris oleracea, known as the mustard white, is a butterfly in the family Pieridae, native to Canada and northeastern US. Adults feed on Brassicaceae plants, with larvae facing threats from toxic invasive plants like garlic mustard. The species' populations are declining due to environmental changes, invasive species, and habitat loss.

Physical Characteristics

Wingspan of 23-50 mm. Adults are nearly all white with a small patch of black scales at the tips of the wings. Distinct green or yellow markings on the underside of the hind wings that run along the veins.

Identification Tips

Distinction from closely related species P. angelica and P. marginalis is primarily based on geographic distribution. Spring form shows prominent green markings on the underside, while summer form is nearly all white.

Habitat

Found in prairies, near streams, and in moist deciduous areas. Prefers woodlands or open fields in the spring.

Distribution

Mainly found throughout Canada (from Newfoundland to Alberta) and parts of the northeastern United States (including New England and the Great Lakes region). Specific populations in British Columbia, Nunavut, and Saskatchewan.

Diet

Caterpillars primarily feed on plants in the Brassicaceae family (mustard plants), such as Cardamines and Boechera. Adults consume nectar from the same plants.

Life Cycle

Biovoltine species, typically having two broods seasonally, with one flight period in June and another by late July. In southern Ontario, can have three to four generations; in northern areas, may have only one generation.

Reproduction

Females prefer to lay eggs on members of the Brassicaceae family, which serve as host plants for the larvae. Recent studies indicate possible adaptation to the toxic garlic mustard (Alliaria petiolata).

Predators

A. petiolata is toxic to larvae and may hinder their survival. P. rapae competes with P. oleracea for foraging sites.

Conservation Status

Populations are declining due to climate change, invasive species (like garlic mustard), and habitat loss due to human development.

Ecosystem Role

Serves a role in pollination and is part of the food web, supporting various predators during its life stages.

Evolution

Closely related to Eurasian P. napi, indicating possible divergent evolution with regional adaptations. Potential adaptation to garlic mustard is under study, with concerns about the pace of this process.