A new species of gall midge (Diptera: Cecidomyiidae) associated with Peumus boldus (Monimiaceae) in Chile

Chile is characterized by high levels of endemism among its flora and fauna, yet its diverse gall-inducing organisms remain poorly studied. We describe Dasineura peumi sp. nov., a new gall-inducing midge (Diptera: Cecidomyiidae) associated with Peumus boldus Molina (Monimiaceae), an economically significant medicinal plant native to Chile’s sclerophyllous forests. This species induces solitary or clustered fusiform galls on the stems, each housing a single larva. Morphological and phenological analyses were conducted on samples collected in the Bíobío Region of Chile in 2021 and 2022. Morphological studies revealed key diagnostic traits: antennae with 18 flagellomeres in both sexes, tarsal claws with a prominent basal tooth, as long as the empodia, and a band-like male tergite 8. The ovipositor measures 1.0-1.10 mm, approximately four times the length of the seventh tergite. Pupae are characterized by long vertical setae, very short antennal horns, a complete arrangement of facial papillae, digitiform prothoracic spiracles, and spines absent from the abdomen. Larvae possess a long spatula with two anterior teeth and an anchor-like base, a complete arrangement of lateral papillae, and eight short, uniform terminal papillae. This species has a multivoltine life cycle, with development independent of the host plant’s phenology.