Alfalfa (Medicago sativa) is a perennial plant from Fabaceae family, cultivated as an important forage crop in many countries around the world. During the vegetation period, alfalfa is attacked by a series of pests that can cause significant yield losses that reach up to 40 - 50% (in case of seed crops). Among these pests, heteropterous insects are considered to be the most damaging. The Heteropterans or “true bugs” are among the most diverse groups within the Hemiptera, and are commonly identified by the strong odors produced by the metathoracic scent glands. They pierce tissues of plants and feed on their juices, live as entomophagous and many of them are serious plant pests. In the climatic conditions in the western part of Romania (Hateg: Hunedoara), a significant presence has the heteropterous insects (plant bugs), 23 specie being collected. The present paper contains new data on the heteropterous insects species encountered in the alfalfa crops, a brief classification of the species and the plant bug feeding habits and host plants. Specimens were collected from alfalfa crop by hand and using sweep net methods. There were 747 specimens belonging to 23 species, from which 5 species: Deraeocoris serenus, Deraeocoris trifasciatus, Nysius thyme, Alydus calcaratus, Camptopus lateralis are new records for the investigated area. The experiments conducted in Hunedoara County, on alfalfa crop shows that insects from Miridae, Coreidae and Pentatomidae family produces serious damage when they feed on alfalfa plants causing lesions along the main steam, leaf petioles and leaves. Two rare species (Deraeocoris trifasciatus and Nysius thymi) were mentionated from the first time in the Heteroptera fauna from alfalfa crop, in Hunedoara County, this species being known only in a few locations in Romania until now. The invasive brown marmorated stink bug (Halyomorpha halys Stål, 1855) species is present for the first time on this crop.

heteropterous insects, alfalfa, western Romania, feeding habits, host plants

biology

Presentation: poster