First record of Ornithocoris pallidus (Hemiptera: Cimicidae) associated with Hyacinth macaw (Anodorhynchus hyacinthinus) nest in the Brazilian Pantanal

Abstract

This study reports the first record of Ornithocoris pallidus associated with a Hyacinth Macaw (Anodorhynchus hyacinthinus) nest in the Brazilian Pantanal supported by integrative morphological and molecular identification. Ectoparasites associated with nests can compromise the health and development of birds that use reused cavities, such as the hyacinth macaw. Among these parasites, blood-feeding bugs of the Cimicidae family remain poorly studied in wild environments. Accordingly, the specimens were collected in February 2025 from a natural cavity containing a blue macaw chick and from a nest box occupied by muscovy duck (Cairina moschata). Identification was performed using light microscopy and scanning electron microscopy, following the diagnostic taxonomic key, as well as partial sequencing of the cytochrome c oxidase subunit I (COI) gene. The observed morphological characteristics were consistent with Ornithocoris pallidus, including the presence of 1 + 1 long setae on the posterolateral margin of the pronotum, which is a diagnostic taxonomic character for the species. The obtained sequence (306 bp) showed 96.73% identity with sequences available in GenBank for the species. The results expand our knowledge of the distribution and host range of O. pallidus, in addition to contributing to previously unpublished molecular data on cimicids associated with Neotropical avifauna, reinforcing the importance of integrating the monitoring of threatened birds with parasitological assessment.