Stictomyia longicornis

Bigot, 1885

Stictomyia longicornis is a small picture-winged fly in the Ulidiidae. measure approximately 4 millimeters in length and are found almost exclusively on prickly-pear cacti in the southwestern United States. The has been reared from rotting cactus pads, indicating larval development in decaying cactus tissue. Adults are morphologically unusual among flies, with short wings plastered to the back and a -like or true -like appearance.

Picture-winged fly on jumping cholla (14023260424) by Katja Schulz from Washington, D. C., USA. Used under a CC BY 2.0 license.

Stictomyia longicornis P1080985a by
xpda. Used under a CC BY-SA 4.0 license.

Picture-winged fly on jumping cholla (13999692376) by Katja Schulz from Washington, D. C., USA. Used under a CC BY 2.0 license.

Pronunciation

How to pronounce Stictomyia longicornis: /ˌstɪktoʊˈmaɪə ˌlɒŋɡɪˈkɔrnɪs/

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

Identification

Distinguished from other Ulidiidae by its extremely short wings held flat against the body, rather than spread or patterned in display. The -like or -like silhouette contrasts with the more typical fly-like appearance of relatives. Found specifically on prickly-pear cacti, whereas similar-sized ulidiids such as Ceroxys occur on different and have longer wings with bold patterns. The Stictomyia is recognized by this distinctive wing reduction and body form.

Images

Appearance

are approximately 4 millimeters long. The wings are short and plastered flat against the surface of the body. The overall body form resembles beetles or true bugs more than typical flies. The compact, flattened wing posture and small size contribute to a distinctive non-dipteran appearance.

Habitat

Associated with prickly-pear cacti (Opuntia ) in arid and semi-arid regions. Larval consists of rotting cactus pads. habitat includes the surfaces and spines of living cactus plants, where they move between bundles of spines.

Distribution

Southwestern United States. Documented from Colorado Springs, Colorado. Distribution corresponds with prickly-pear cactus range, and the likely occurs wherever suitable cacti are present.

Diet

Larvae develop in rotting prickly-pear cactus pads. feeding habits are not documented.

Host Associations

Opuntia - larval developmentprickly-pear cactus; larvae in rotting pads

Life Cycle

Larval stage develops within rotting pads of prickly-pear cactus. emerge and remain associated with cactus plants. Specific details of deposition, , and developmental duration are not documented.

Behavior

rarely fly. Movement consists primarily of and dodging between bundles of cactus spines. This , combined with the flattened wing posture, represents an unusual locomotory strategy among Diptera.

Ecological Role

Contributes to decomposition of cactus tissue through larval feeding in rotting pads. Role in nutrient cycling within cactus-dominated .

Human Relevance

No documented economic or medical importance. Not known to be a pest of cultivated cacti or to enter human structures.

Similar Taxa

Ceroxys latiusculusAnother small ulidiid, but has longer patterned wings held in typical fly posture, and occurs on Senecio plants rather than cacti
Delphinia pictaCommon eastern ulidiid of similar size but with bold wing patterns and association with decaying organic matter and compost rather than cacti
Tephritidae (fruit flies)Some fruit flies share small size and patterned wings, but have fully developed wings and different body proportions; not associated with cacti

More Details

Taxonomic note

Ulidiidae was formerly treated as in older literature. The Stictomyia is characterized by reduced, appressed wings that depart dramatically from the typical wing display of most picture-winged flies.

Morphological adaptation

The short, plastered wings and cryptic movement among cactus spines suggest for avoidance in an exposed, spiny environment where may be disadvantageous.