Study aim. To assess the variety composition and taxonomical dependence of macromothes in Žuvintas biosphere rezerve ecological preservative zone. Study goals: 1. To investigate the macromothes fauna in Žuvintas biosphere rezerve ecological preservative zone. 2. To investigate rare, very rare and widely distributed macromothes in Lithuania, Žuvintas biosphere rezerve ecological preservative zone. To prepare recomendations for the very rare mothes preservation. Study object. The macromothes of Žuvintas biosphere rezerve. Methods. The data collected from 2005 05 29 till 2005 10 15 in Žuvintas biosphere reserve. The macromothes were tempted by using a 700 W luminescencical lamp all the summer and the beginning of autumn starting at late hour 23 till 3 at night. All the mothes met were caught into poisoning catcher. The number of macromothes was recorded. The macromothes were described according to taxonomical and trophical dependence, distribution and plenty (R. Kazlauskas, P. Ivinskis, A. Gedminas). Results. 80 macromothes species were captured in Žuvintas biosphere rezerve ecological preservative zone which depended to 11 families. The most common is Noctuidae family – 46 species. The captured macromothes had 9 very rare species and 11 rare species not only in Lithuania, but also in Baltic States. 6 species of mothes are rare in Lithuania and other Baltic states. They are: Herse convolvuli, Simyra nervosa, Oligia strigilis, Arenostola phragmitidis, Lygephila craccae... [to full text]