First record of a native specialist ant cricket in a colony of the invasive Argentine ant <i>Linepithema humile</i>

Abstract Invasive species often exert substantial impacts on native ecosystems and may provide native parasites—including potentially even specialist parasites—with opportunities to encounter novel hosts. Here, we show that a native host‐specific social parasite can occur within colonies of an invasive ant. We surveyed nests of the Argentine ant Linepithema humile (Hymenoptera: Formicidae) in Osaka, Japan, and collected the ant cricket Myrmecophilus tetramorii (Orthoptera: Myrmecophilidae) and the silverfish Nipponatelurina kurosai (Zygentoma, Ateluridae). Notably, M. tetramorii is a specialist parasite known to exclusively exploit the native ant Tetramorium tsushimae (Hymenoptera: Formicidae), and its occurrence in a L. humile colony represents, to our knowledge, the first documented record of a specialist social parasite occurring in a colony of an invasive ant. Whether these parasites are able to reproduce or establish stable populations within L. humile colonies requires further investigation. However, our study demonstrates that direct ecological contact with a novel host is occurring in the field. This report provides important implications for understanding the initial stage of host‐range expansion not only in generalist parasites but also in parasites with strong host specificity under biological invasions.