Plant bugs (Heteroptera: Miridae) associated with roadside habitats in Argentina and Paraguay: Host plant, temporal, and geographic range effects

Abstract

Between November 1999 and September 2001, mirid nymphs (Hemiptera: Miridae) were collected on wild and cultivated plants in central and northern Argentina and southeastern Paraguay. In the laboratory, nymphs were reared until adult emergence. Four (Bryocorinae, Deraeocorinae, Mirinae, and Orthotylinae) of the eight mirid subfamilies were collected during the study. Twenty-two mirid species on 43 putative host plant species were collected in Argentina, and five species of mirids on eight plant species were collected in Paraguay. Eighty-five new mirid-plant associations were recorded (only 112 mirid-plant associations had been reported previously for Argentina). Most of the mirids were in the subfamily Mirinae, tribe Mirini, and most of the host plants belonged to Asteraceae. Almost all mirids were collected on plants with flower buds present. In addition to host plant records, the phenology and pattern of plant use for the most abundant mirids are reported. Mirid richness and abundance varied according to the host plant species; the highest diversity and richness of mirids occurred in the western region of Argentina (Salta, Jujuy, and Tucumán provinces). The most frequently collected mirid, Taylorilygus apicalis (Fieber) (≈87% of the 35,970 collected mirids), was usually collected on Asteraceae. This exotic species could have affected the native mirid fauna in the study area. More research on the possible interactions between T. apicalis and the native mirids of Argentina and Paraguay is needed. Our results suggest that T. apicalis exhibits regional polyphagy, i.e., uses numerous hosts throughout its geographic range.