Open Access

Frank E. Kurczewski, Joseph W. Stoll, Rick C. West, Kelly C. Kissane, Paige R. Chesshire, Neil S. Cobb

• This paper is the sequel to a 20 year-long (2002–2021) study of geographic variation in host selection in the common American spider wasps (Hymenoptera: Pompilidae) Entypus unifasciatus (Say) (Pepsini) and Tachypompilus ferrugineus (Say) (Pompilini) (rusty spider wasp). Geography and host spider family are strongly linked in both species when 3387 host spider locality records from the years 1918–2021 are mapped. Entypus unifasciatus lycosid host records are plentiful from 43–44° N in the United States and southern Ontario to northern Mexico. Tachypompilus ferrugineus lycosid host records are abundant from southern Ontario and New England southward to Mexico east of the Rocky Mountains. The vast majority (~80%) of E. unifasciatus and T. ferrugineus pisaurid host records are from the southeastern United States. Trechaleid host records for E. unifasciatus and T. ferrugineus are predominant in southern Mexico and Central America, while ctenid host records for these spider wasps are prevalent in Central America and, especially, South America. All E. unifasciatus sparassid host records are from extreme southwestern United States and northern Mexico, whereas T. ferrugineus sparassid host records are scattered from Texas, Florida and Hispaniola/Puerto Rico southward to Panama and Brazil. Based on this study Lycosidae is the predominant host spider family in the Americas for E. unifasciatus (83.1%) and T. ferrugineus (64.0%) followed by Pisauridae (4.9%, 24.8%), Trechaleidae (4.2%, 6.0%), Ctenidae (4.3%, 2.7%), and Sparassidae (3.1%, 1.6%). Lycosidae and Pisauridae are overrepresented in this study as most host records (88.1%) are from the United States and Ontario, Canada where such species are abundant. Trechaleidae and Ctenidae are grossly underrepresented as host records from Mexico, Central America and South America are scarce (11.9%). Zoropsidae/Miturgidae and Zoropsidae / Agelenidae / Selenopidae are atypical host spider families for E. unifasciatus (0.2%, 0.2%) and T. ferrugineus (0.7%, 0.2%, <0.1%), respectively. Rabidosa rabida (Walckenaer) (Lycosidae) (rabid wolf spider) is the predominant host spider species for both E. unifasciatus (47.7%) and T. ferrugineus (48.0%) based mainly on United States host records.