During March 2000, nymphs and adults of the cyrtocorid bugs Cyrtocoris egeris Packauskas & Schaefer and C. trigonus (Germar) were observed on two different plants at two different localities. In Brazil (Londrina, Paraná State) adult C. trigonus were found feeding on stems of the weed plant arrow leaf sida, Sida rhombifolia L. (Malvaceae). Despite egg deposition in the laboratory, nymphs did not develop on this plant. In Argentina (Reconquista, Santa Fé Province), nymphs and adults of C. egeris were observed feeding on immature soybean [Glycine max (L.) Merrill] pods. Under laboratory conditions, nymphs of neither species could be reared beyond the third instar.
Heteroptera; Sida rhombifolia; Glycine max; soybean; ecdysis; geographical distribution