Euxesta stigmatias

Loew, 1868

Cornsilk fly, Maize silk fly

Euxesta stigmatias is a ( ) known as the cornsilk , a significant agricultural pest of maize in tropical and subtropical regions of the Americas. The has established in North America, including Florida and Hawaii. develop inside corn ears, feeding on and kernels, where they are protected from by the surrounding tissue. The species exhibits a normally saprophytic lifestyle but becomes destructive when corn is available.

Pronunciation

How to pronounce Euxesta stigmatias: /juːkˈsɛstə stɪɡˈmeɪʃiəs/

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

Identification

Distinguished from other corn-attacking ulidiids by combination of dark metallic green to black body coloration and specific pattern markings. In Florida, may be confused with three other cornsilk : Chaetopsis massyla, Euxesta annonae, and Euxesta eluta. Wing pattern and dark metallic coloration help separate it from these species. Characteristic wing-flapping provides additional field recognition cue.

Appearance

-sized with dark metallic green to black body coloration. display distinctive patterned markings characteristic of ( ). Exhibits a characteristic wing-flapping when at rest.

Habitat

Agricultural landscapes dominated by maize . In range, tropical and subtropical corn-growing regions. In invaded range, established in southern Florida agricultural and Hawaii. Development occurs specifically within corn ears during fructification and grain maturation stages.

Distribution

to tropical and subtropical regions of the Americas. Established in Florida, USA (); recorded from Hawaii, USA; Galápagos Islands. Documented in Mexico (Sinaloa), Puerto Rico, Argentina, Ecuador, and Guatemala. Range expanding in North America.

Seasonality

Active during corn growing seasons. In Sinaloa, Mexico, observed during spring-summer agricultural cycle (March-July), with peak activity during fructification and grain maturation stages. In Florida, present throughout the year in agricultural with overlapping corn production cycles.

Diet

feed on maize and developing kernels, causing direct damage and associated fungal rot. normally saprophytic, feeding on decaying matter; shift to corn ears when available.

Host Associations

Zea mays - primary Sweet corn and maize; larval development occurs within ears
Spodoptera frugiperda - indirect association damage to corn attracts ovipositing females
Helicoverpa zea - indirect association damage attracts

Life Cycle

laid on or near corn . develop inside corn ears (elotes/grains), feeding on silk and kernels while protected within leaf wrapping. occurs in pupal chambers formed within corn ear leaf tissue or surrounding debris. Multiple per year possible in suitable climates.

Behavior

Exhibits distinctive -flapping when at rest. Females attracted to corn ears, particularly those with pre-existing damage from lepidopteran pests. Larval development occurs within protective corn ear structure, rendering inaccessible to contact . normally saprophytic, shifting to corn ears when available.

Ecological Role

Agricultural pest causing direct feeding damage and facilitating secondary fungal that reduce grain quality and yield. Serves as for including (Spalangia spp., ; ) and (Orius insidiosus, , , ). Potential host for nematodes (Rhabditidae).

Human Relevance

Major economic pest of sweet corn and maize production. Entire fields may be rejected for harvest if untreated or if treatments are missed due to weather or timing constraints. status in North America requires ongoing management. Subject to research using and .

Similar Taxa

Euxesta elutaAlso attacks corn in Florida; distinguished by pattern and coloration differences
Euxesta annonaeCorn pest in Florida; similar use but distinguishable by markings
Chaetopsis massylaMember of cornsilk pest complex in Florida and Mexico; different but similar ecological role and damage

More Details

Natural enemies

In Sinaloa, Mexico, Spalangia spp. (: ) parasitizes with 47% natural observed in experimental plots. The pirate Orius insidiosus (: ) preys on and March-July. Additional include Coleomegilla maculata, Cycloneda sanguinea, Hippodamia convergens, Metasyrphus sp., and Chrysoperla spp.

Management challenges

Larval protection within corn ears makes chemical control difficult. timing critical due to concealed feeding habit. agents show promise for programs.