Geomyza tripunctata

Fallén, 1823

Cereal Fly

Geomyza tripunctata is a small fly in the Opomyzidae, commonly known as the Cereal Fly. It is distributed across the Palearctic region from Europe to Siberia, with records extending to North Africa. The is associated with grassland and cereal agriculture, where larvae develop as stem borers in grasses and cereals.

Geomyza tripunctata by (c) Miroslav Deml, some rights reserved (CC BY). Used under a CC-BY license.

The fly Geomyza tripunctata, Waddicar, Melling - geograph.org.uk - 4123652 by Mike Pennington . Used under a CC BY-SA 2.0 license.

Geomyza tripunctata (Opomyzidae) - Flickr - gailhampshire (1) by gailhampshire from Cradley, Malvern, U.K. Used under a CC BY 2.0 license.

Pronunciation

How to pronounce Geomyza tripunctata: /ˈɡeɪ.əˌmaɪ.zə trɪˌpʌŋkˈteɪ.tə/

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

Identification

Small opomyzid fly; specific diagnostic features not documented in available sources.

Images

Habitat

Grassland and cereal fields. Found in agricultural settings and natural grassland .

Distribution

Palearctic region: Europe (common throughout), Norway, Lapland, Siberia, Algeria, Tunisia. Recorded up to 2,300 m elevation. Present in Belgium, Denmark, Norway, Portugal (Madeira).

Seasonality

activity from May to November.

Diet

Larvae feed inside stems of grasses and cereals, killing the central shoot. In the field, chief larval plants are Lolium perenne and L. italicum; in laboratory conditions, other grasses and wheat are readily attacked.

Life Cycle

Larvae tunnel in stems of grasses and cereals. Larval densities decline significantly from October through winter, with commencing between mid-February and early March.

Behavior

Larvae aggregate in patches on a small within grassland. Larval is described by the negative binomial distribution and likely results from heterogeneous Poisson sampling and true contagion (preference for favorable oviposition sites).

Ecological Role

Pest of cereal crops and grasses. for hymenopterous including Chasmodon apterus, Halticoptera circulus, Hexacola hexatoma, Opius , and Rhoptromeris heptoma. levels in G. tripunctata ranged from 3.9% to 56.4% in field studies.

Human Relevance

Agricultural pest affecting cereal production. Larval feeding damages cereal crops by killing central shoots, similar to damage caused by .

Similar Taxa

Oscinella fritSimilar damage pattern to cereals; both are frit flies with larvae that kill central shoots of grasses. G. tripunctata distinguished by Opomyzidae versus Chloropidae.
Oscinella spp.Co-occurs in grassland and shares ; distinguished by -level and specific plant associations.

More Details

Parasitoid pressure

Chasmodon apterus dominated the complex in northern England studies, accounting for 40-90% of parasitoids across three years (1984-1986). was inversely -dependent in whole grass fields.

Mortality factors

Autumn-winter mortality significantly reduces larval ; 45-73% of October larval numbers lost by December/January, possibly due to unidentified -dependent mortality factors.