Blood-sucking arthropods collected from swallow nests in Honshu, Japan, with comparison of new and used nests

: From 2015 to 2020, we investigated the arthropods except psocids and micro mites inhabiting the nests of three species of swallows from six prefectures (Ibaraki, Saitama, Tokyo, Kanagawa, Nagano, and Shizuoka) in Honshu, Japan. Sixty-three nests were examined ̶ 51 for the barn swallow Hirundo rustica , and 6 each for the house martin Delichon dasypus and the house swift Apus nipalensis . More than 13 species of arthropods were found in the nests, including Oeciacus hirundinis (Hemiptera: Cimicidae), Anthocoridae gen. sp. (Hemiptera), Stenepteryx hirundinis (Diptera: Hippoboscidae), Ceratophyllus farreni chaoi (Siphonaptera: Ceratophyllidae), Ceratophyllus gallinae dilatus (Siphonaptera: Ceratophyllidae), Dermestidae gen. sp. (Coleoptera), Ptinidae gen. sp. (Coleoptera), Anobiidae gen. sp. (Coleoptera), Lepidoptera gen. sp., Argas japonicus (Acari: Argasidae), Ornithonyssus sylviarum (Acari: Macronyssidae), Dermanyssus hirundinis (Acari: Dermanyssidae), and Araneae gen. sp. Ceratophyllus gallinae dilatus and A. japonicus were collected from nests of H. rustica for the first time. Furthermore, H. rustica was recorded as a new host of S. hirundinis in Japan. The detection rates of blood-sucking arthropods in the new nests (nests built the year they were removed) and used nests (nests built on old material, and used up to the year the nest was removed) of H. rustica were compared. Ceratophyllus gallinae dilatus and A. japonicus were not collected from new nests, but were collected from used nests and there was a significant difference in the detection rates of both species from new and used