Saucer Gall Wasp
Feron gigas
The gall is not built by the wasp, but by the oak tree itself, manipulated by the wasp's chemical secretions to grow a custom-made nursery.
- Scientific name
- Feron gigas
- Taxonomy
- Animalia › Arthropoda › Insecta › Hymenoptera › Cynipidae › Feron
- IUCN Red List status
- Least Concern
- Population trend
- stable
- Biome
- forest
- Habitat
- Oak woodlands, mixed deciduous forests, and suburban areas containing oak trees.
- Diet
- Larvae feed on specialized plant tissues inside the gall; adults feed minimally on nectar or water.
- Range
- North America, United States, California
- Size
- Adults: 2-4 mm; Galls: 5-8 mm in diameter.
- Lifespan
- Adults live 1-2 weeks; full life cycle takes 1 year.
- Active
- diurnal
- Threats
- Loss of mature oak woodlands, urbanization, and widespread chemical pesticide application.
- Safe to approach?
- Harmless. These tiny wasps do not possess a functional stinger and cannot harm humans. You can safely observe them or their saucer-like galls on the undersides of oak leaves at any distance.
Feron gigas , also known as the saucer gall wasp , is a species of gall-forming wasp in the genus Feron. It induces galls on the leaves of scrub oaks, blue oaks, and Engelmann oaks. The galls produced by its all-female generation, which emerges in winter, are 3-4 mm wide, circular with raised edges. They are red, pink, brown, or purple. The larval chamber exists as a raised bump in the gall's center. The bisexual generation produces galls...
Photo: Ken-ichi Ueda, CC-BY, via iNaturalist
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