New fossil nematodes in Dominican and Baltic amber

Four new species of fossil mermithids (Nematoda: Mermithidae) are described from amber: Heydenius arachnius n. sp. from a spider (Arachnida: Araneae) in Dominican amber, H. phasmatophilus n. sp., from a walking stick (Phasmatodea: Phasmatidae) in Baltic amber, H. podenasae n. sp. from a moth (Lepidoptera) in Baltic amber and H. trichorosus n. sp. from a caddis fly (Trichoptera: Leptoceridae) in Baltic amber. With previous descriptions of fossil mermithids from Diptera, Coleoptera, Hymenoptera and Hemiptera, there are now representatives of seven insect orders as hosts of fossil mermithids. With these additional four fossils, the total number of described nematode fossils is now 95, with 70 occurring in amber.