Host Plant Selection in Phyllonorycter Species Living on Willows and Their Hybrids (Lepidoptera: Gracillariidae)

Own knowledge on host plants and on the breadth of the trophic specialization of central European species of Phyllonorycter Hubner, 1822 living on Salix spp. obtained over the past 60 years are presented. A total of 8 species were evaluated and divided into four groups after their trophic relationships; monophagous species: Phyllonorycter quinqueguttella (Stainton, 1851) on Salix repens s. l., and P. viminetorum (Stainton, 1854) on Salix viminalis (here only provisorly due to the small number of reared specimens); narrowly oligophagous species: P. dubitella (Herrich-Schaffer, 1855) and P. salicicolella (Sircom, 1848), both on Salix species of the section Capreae; oligophagous species: P. hilarella (Zetterstedt, 1839) and P. salictella (Zeller, 1846) on many Salix species, each with different trophic preferences; broadly oligophagous species: Phyllonorycter connexella (Zeller, 1846) and P. pastorella (Zeller, 1846) developing on Salix and Populus species. The hybrids are also used as host plants, and the laying females positively respond to them as well as to the biological Salix species, if at least one of the parental species is the usual host of the relevant Phyllonorycter species. The data on host plants reported by other authors are compared.