Mormidea lugens

(Fabricius, 1775)

Mormidea lugens is a small in the Pentatomidae, distributed across the Caribbean, Central America, and eastern North America. In southern Illinois, it exhibits a with and emerging in late April, persisting until early November. The develops on various grasses and sedges, with nymphs feeding on vegetation and adults targeting developing grass seeds. It is considered a potential pest of wheat and other small grains.

Mormidea lugens SERC 05-16-15 (17847760206) by Smithsonian Environmental Research Center. Used under a CC BY 2.0 license.

Mormidea lugens (48404116981) by Christina Butler from Georgia, United States. Used under a CC BY 2.0 license.

Mormidea lugens, U, Back, MD, PG County 2013-07-31-20.03.34 ZS PMax by Sam Droege. Used under a CC BY 2.0 license.

Pronunciation

How to pronounce Mormidea lugens: /mɔrˈmɪdiə ˈluːdʒɛns/

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

Identification

The bronze coloration combined with the white-yellow scutellar border distinguishes Mormidea lugens from similar pentatomids. The small size (under 8 mm) and grass-associated further aid identification. Euschistus politus, which occurs sympatrically in southern Illinois, differs in coloration and preferences.

Images

Appearance

are bronze in color with a distinctive white-yellow border around the scutellum. Body length ranges from 5.0 to 7.2 mm. are approximately 0.7 mm in diameter, pale yellow, and laid in small clusters.

Habitat

Grassy areas including fields, meadows, and agricultural settings with abundant grasses and sedges. In Illinois, associated with timothy, sedges (Carex shortiana, C. amphibola, C. normalis, C. blanda), deer-tongue grass (Panicum clandestinum), and Bosc's panic-grass (P. boscii).

Distribution

Caribbean, Central America, and eastern North America. Documented from southern Illinois with specific biological studies; Vermont records confirmed via GBIF.

Seasonality

In southern Illinois, emerge from sites in late April and remain active until early November. Laboratory development from to adult takes 39–50 days at approximately 24°C, with plant affecting duration.

Diet

Nymphs feed on various grasses and sedges. feed on developing seeds of grasses. Documented include timothy, multiple Carex sedge , deer-tongue grass, and Bosc's panic-grass. Deer-tongue grass appears insufficient for complete development. Collected from pale sedge and wide-leaved spiderwort but not observed feeding on these.

Host Associations

timothy (Phleum pratense) - food plantnymphs and
Carex shortiana - food plantsedge, nymph development
Carex amphibola - food plantsedge, nymph development
Carex normalis - food plantsedge, nymph development
Panicum clandestinum - food plantdeer-tongue grass; insufficient for development
Panicum boscii - food plantBosc's panic-grass
Triticum aestivum - potential pest wheat, feed on developing seeds

Life Cycle

(one per year) in southern Illinois, though some sources suggest potential. overwinter and emerge in spring. are laid in small clusters of 6–11 eggs (mean 9.6). Five nymphal instars precede adult in late summer. Laboratory egg hatch occurs in 6–7 days.

Behavior

Overwinters as . Exhibits . Nymphs develop on non-crop grasses and sedges before adults may move to grain crops. Development time varies with plant .

Ecological Role

Herbivore specializing on grass seeds. Serves as prey for natural enemies. Potential agricultural pest of wheat and small grains through seed feeding.

Human Relevance

Considered a potential pest of wheat and other small grains due to feeding on developing seeds. Not a major economic pest compared to other pentatomids.

Similar Taxa

Euschistus politusOccurs sympatrically in southern Illinois; differs in coloration and plant associations
Other Mormidea speciesRequires examination of genitalia and subtle color pattern differences for definitive identification

More Details

Developmental plasticity

Laboratory studies show development time from to varies with plant , suggesting host quality affects .

Voltinism uncertainty

Some sources describe the as in southern Illinois, while others note potential patterns in the same region. This may reflect variation or methodological differences.