First Record of Tropical Sod Webworm on Turfgrass in Brazil.

Climate change and anthropogenic disturbance in agricultural production systems can facilitate shifts in the distribution of arthropod pest species and in the range of plant hosts on which they feed. This study presents the first record of Tropical Sod Webworm (TSW), Herpetogramma phaeopteralis Guenée (Lepidoptera: Crambidae: Spilomelinae), on native or nativized species of the genus Axonopus (Poaceae) in Brazil. The occurrence of population outbreaks of this species was observed in March and April of 2024 among smallholder cattle farmers in Capão Alto and Campo Belo do Sul, both municipalities situated in the highlands of Santa Catarina State, southern Brazil. The caterpillars feed on leaves during the nocturnal nighttime period, causing extensive defoliation and forming large dry patches of grass. Phylogenetic analyses based on mtCOI support the morphological characterization indicated that the species is H. phaeopteralis. The phylogenetic tree, based on partial sequences of the COI gene, indicated that the Brazilian isolate is more closely related to the Peruvian isolate and is distinct from the American and Japanese isolates. Turfgrass production is an economically important activity in Brazil and, thus, H. phaeopteralis should be monitored to assess its establishment as a primary pest in the landscapes where host plants are employed.