Impact of elevation on Noctuidae moth diversity in Eastern Iran: insights into species richness and community structure in the Bagheran protected area

Noctuid moths (Lepidoptera: Noctuidae) are highly diverse, yet their altitudinal distribution patterns remain poorly understood in eastern Iran. We investigated species distribution and assemblage patterns across an elevation gradient of 1500–2500 m a.s.l. in the Bagheran Protected Area (Birjand, E Iran). Adult moths were sampled using light traps across 23 independent sites (4–5 sites per elevation class) over two years. The total number of specimens collected was 3228 for 39 different species, with Bryophila maeonis (Lederer, 1865) being dominant (23.2%). Altitude had significant effects on species richness and diversity indices (p ≤ 0.05). Richness was consistent with the mid-altitude peak concept, rising up to an intermediate altitude and then falling above that altitude. The species abundance distribution (SAD) followed a log-normal curve (AIC = 288.98, BIC = 292.30), indicating a relatively stable but moderately stressed community structure. The low number of recorded species (S = 39) and the low values of the Shannon-Wiener index (≤ 1.99) imply that the noctuid community is delicate and requires protection measures. Our results show the significance of Noctuidae in dry mountain environments from an ecological perspective.