Neacoryphus bicrucis

(Say, 1825)

Whitecrossed seed bug, Ragwort seed bug, White-crossed seed bug

Neacoryphus bicrucis is a seed-feeding true (Hemiptera: Lygaeidae) commonly known as the whitecrossed or ragwort seed bug. The is specialized on Senecio species as plants, from which it sequesters that render it distasteful to some . It exhibits complex territorial and mating centered on host plant patches, with males defending high- areas where females preferentially oviposit. The species shows pronounced in behavior: females conditionally histolyze flight muscles based on resource availability, while males retain flight capability throughout life. It has a broad distribution across the Americas and has been introduced to Oceania.

Neacoryphus bicrucis by no rights reserved, uploaded by Some pig. Used under a CC0 license.

Neacoryphus bicrucis by no rights reserved, uploaded by Jesse Rorabaugh. Used under a CC0 license.

Neacoryphus bicrucis by (c) Annika Lindqvist, some rights reserved (CC BY), uploaded by Annika Lindqvist. Used under a CC-BY license.

Pronunciation

How to pronounce Neacoryphus bicrucis: /niːəˈkɔːrɪfəs baɪˈkruːsɪs/

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

Identification

The "whitecrossed " refers to a distinctive white cross-shaped marking on the surface. As a member of Lygaeidae, it has the typical elongate-oval body form and with membranous portions characteristic of seed bugs. Specific diagnostic features distinguishing it from and similar lygaeids are not documented in available sources.

Images

Habitat

Associated with patches of Senecio plants, particularly in areas of high host plant . Documented from granite outcrops, old fields on coastal plains, piedmont regions, and Blue Ridge Mountains in Georgia, USA. Also recorded from Illinois sand prairie. use is strongly density-dependent, with most numerous in large host plant patches and areas of highest plant density within patches.

Distribution

Native to the Americas with records from USA, Guatemala, Nicaragua, Panama, Brazil, Colombia, French Guiana, and Venezuela. Introduced to Oceania (Hawaii). Present in Central America, North America, and South America.

Diet

Specialized seed-feeder utilizing only Senecio as plants. Feeds on seeds of Senecio smallii and other Senecio spp. reared on alternative hosts such as sunflower seeds (Helianthus annuus) lack defensive compounds and are palatable to .

Host Associations

Senecio smallii - primary Source of
Senecio spp. - primary Exclusive plants across multiple Georgia

Life Cycle

stage followed by nymphal development on plants. marks transition to reproductive phase. Females may undergo muscle histolysis shortly after eclosion when food and mates are abundant, shifting resources to . possible under short-day . Oviposition occurs preferentially in areas of high host plant .

Behavior

Males establish and patrol small territories composed of plants, expelling rival males and unreceptive females. Territory quality correlates with host plant and female density; larger males aggressively exclude smaller males from prime territories, resulting in higher mating frequency. Courtship is aggressive and resembles territorial . Males remain longer in patches with higher host plant density and where they have recently mated. Long-distance occurs by at high altitudes; flight tendency increases in males under food or mate deprivation. Starved individuals can survive over one month with minimal decline in flight ability.

Ecological Role

seed of Senecio, potentially influencing plant through seed consumption. Chemical defense through sequestered alkaloids creates predator-prey interactions of variable outcome: unpalatable to green anole lizards (Anolis carolinensis) but palatable to Fowler's toads (Bufo woodhousei fowleri).

Similar Taxa

Other LygaeidaeSimilar body plan; distinguished by plant specificity and white cross marking
Other Neacoryphus species likely overlap in distribution; specific diagnostic characters not documented

More Details

Chemical Defense

Sequesters from Senecio plants, which may cause distastefulness to green anole lizards. reared on non-host plants lack this defense.

Flight Physiology

Sex-dimorphic muscle investment represents a trade-off between and . Females show plastic response to environmental cues; males maintain flight capability regardless of conditions.