Adelphocoris rapidus

Distinguished from similar plant bugs by the two large black spots on the pronotum near the hind margin. Nymphs lack the dark spots on the abdomen and thorax found on tarnished plant bug (Lygus lineolaris) and pale legume bug. Eggs have a distinct extension or spine not present in similar species. The larger size (7–8 mm) separates it from most other Miridae.

Adults measure 6.8–7.4 mm in length, larger than most other Miridae. The head, legs, and prothorax are yellowish to red. The pronotum is yellow or yellowish-brown with two large black spots near the hind margin. The hemelytra are brown with narrow yellow lateral edges. Antennae are black with yellowish-white rings. Nymphs change color through five instars: starting yellow, becoming reddish-green, and ending dark. Nymphs have a wide reddish-brown band near the abdomen tip and banded antennae.

Found in agricultural fields, meadows, and areas with host plants including alfalfa, sweet clover, and various weeds. Associated with tall grassy habitats and crop fields.

Widespread in the United States except the central region. Present in Canada at the Peace–Athabasca Delta, Alberta, and Ontario. Also recorded from Cuba and Peru.

Eggs incubate 15–20 days in summer. Nymphal development takes approximately 15.4 days total across five instars. Adults present in summer; nymphs appear in early to mid-season depending on egg laying.

Feeds on alfalfa and sweet clover. Consumes vegetables including beans, carrots, celery, and potatoes. Also feeds on field crops such as cotton and sugarbeet, and weeds including Canada thistle (Cirsium arvense), Rumex species, and yarrow (Achillea).

• alfalfa - food plant
• sweet clover - food plant
• beans - food plant
• carrots - food plant
• celery - food plant
• potatoes - food plant
• cotton - food plant
• sugarbeet - food plant
• Canada thistle - food plantCirsium arvense
• Rumex - food plant
• yarrow - food plantAchillea

Females lay 35–100 greenish-white to yellow eggs singly in plant stems. Eggs are 1.2–1.3 mm long, cylindrical and curved, turning red before hatching. Incubation takes 15–20 days in summer. Nymphs pass through five instars in approximately 15.4 days total. Adults are capable of flight but do not fly high; dispersal is not rapid.

Adults fly low to the ground. Dispersal is slow despite the species name. Eggs are laid singly rather than in clusters.

Serves as prey for the parasitoid Peristenus pallipes in Ontario. Preyed upon by assassin bugs and ambush bugs in Alberta. Preyed upon by the striped lynx spider (Oxyopes salticus) in cotton fields.

Agricultural pest damaging alfalfa, sweet clover, vegetables, cotton, and sugarbeet. Subject to biological control research involving natural predators such as the striped lynx spider.

• Lygus lineolarisTarnished plant bug; nymphs have dark spots on abdomen and thorax absent in A. rapidus; eggs lack the distinct spine of A. rapidus
• pale legume bugNymphs have dark spots on abdomen and thorax absent in A. rapidus; eggs lack the distinct spine of A. rapidus

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Bug Eric: Spider Sunday: Striped Lynx Spider