Polystepha globosa
This record describes Polystepha globosa (species). Recorded family: Cecidomyiidae. Recorded order: Diptera.
Identification and Appearance
This is the only spherical gall found on oaks that is not caused by a cynipid wasp. Goldfinches have been observed opening the galls to feed on the larvae (see blog post here ).
Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Insecta
- Order
- Diptera (Flies)
- Superfamily
- Sciaroidea
- Family
- Cecidomyiidae (Gall Midges and Wood Midges)
- Subfamily
- Cecidomyiinae
- Tribe
- Asphondyliini
- Genus
- Polystepha
Imported taxonomy record. Source availability varies; see the source references and editorial policy below.
Diet and Behavior
Diet: Forms small spherical galls on leaves of black oak ( Quercus velutina ) and perhaps other red oaks, usually on the underside.
About Flies: the wider group
Order-level background for Diptera, the group containing Polystepha globosa. Species-specific details appear above.
Group overview
Diptera includes over 150,000 described species of flies, mosquitoes, and midges. Mosquitoes are the deadliest animal on Earth (CDC). Malaria alone causes ~249 million cases and over 608,000 deaths annually, mostly children under 5 (WHO). Vector-borne diseases account for over 17% of all infectious diseases, causing 700,000+ deaths per year.
Ecological role of the group
Despite their disease impact, flies are critical decomposers and pollinators. Hoverflies alone pollinate hundreds of crop and wildflower species. Flies are also the primary food source for many birds, bats, and fish. Forensic entomology relies heavily on fly species for crime scene analysis.
Economic and practical significance of the group
In the U.S., vector-borne disease cases tripled between 2004-2016, with over 640,000 cases reported in that period (CDC). Tickborne diseases doubled from 22,000 to 48,000 annual reports. Globally, mosquito-borne diseases cost billions in healthcare and lost productivity.
Recorded sources for this group: WHO, CDC, PNAS. Imported estimates may describe particular regions or reporting periods.
Photos of Polystepha globosa (5)
Photo credits: Contributed by Charley Eiseman
Frequently Asked Questions About Polystepha globosa
What is Polystepha globosa?
Polystepha globosa is a species in the family Cecidomyiidae, within the order Diptera.
How big is Polystepha globosa?
Galls are 1/15" in diameter (~2 mm)
What does Polystepha globosa eat?
The diet of the Polystepha globosa includes Forms small spherical galls on leaves of black oak ( Quercus velutina ) and perhaps other red oaks, usually on the underside..