We collected larval trombiculid mites on vegetation monthly from October 1997 to February 2000, and from the heads of sika deer culled in March 2003 in Boso Peninsula, central Japan. Two species of trombiculid mites, Neotrombicula nogamii Takahashi, Takano, Misumi, and Kikuchi and Leptotrombidium scutellare Nagayo, Miyagawa, Mitamura, and Tamiya, occurred on vegetation. Peak numbers of N. nogamii were found in January, and L. scutellare numbers peaked in November. Both species were collected predominantly on the top of Sasa bamboo stems, where they formed clusters, though N. nogamii preferred heights of 40–50 cm. Furthermore, N. nogamii and Walchia masoni (Asanuma and Saito) were collected from deer. These findings indicate that vegetation is an important substrate for some trombiculid mites awaiting hosts.