Erynia pieris (Zygomycetes: Entomophthoraceae), a new pathogen of Pieris rapae (Lepidoptera: Pieridae): description, host range, and notes on Erynia virescens
Erynia pieris Li & Humber (Entomophthorales: Entomophthoraceae) is described for a fungus originally isolated from Pieris rapae (Lepidoptera: Pieridae). The fungus grows and sporulates well on standard mycological media. Primary conidia are ovoid to obovoid, 21–33 × 11–24 μm (averaging 26 × 16 μm, with a length/width ratio of 1.60), uninucleate, bitunicate, and forcibly discharged from bifurcate or irregularly branched conidiophores. Secondary through quaternary conidia are more nearly globose than primary conidia. Nuclei contain prominent, readily stained chromosomal granulations. Cystidia emerge from the host body before the conidiophores, are only slightly thicker than conidiophores at the base, and taper to a blunt apex. Rhizoids are monohyphal on lepidopterans, are little thicker than vegetative hyphae, and have no discoid terminal holdfast; rhizoidal morphology varies considerably between lepidopterous and nonlepidopterous hosts. No resting spores were observed. Laboratory studies demonstrated the pathogenicity of cultures of this fungus on several other lepidopterans (Estigmene acrea, Heliothis zea, Heliothis virescens, Trichoplusia ni, Spodoptera eridania). on the common housefly (Musca domestica), and on potato leafhopper (Etnpoasca fabae). Erynia virescens (Thax.) Remaudière & Hennebert is emended and compared with E. pieris; both species are assigned to Erynia subg. Furia (Batko) Li & Humber, comb. nov. Furia differs from other Erynia subgenera by the presence of cystidia as thick as conidiophores and of rhizoids no thicker than vegetative hyphae and having no differentiated terminal holdfasts, and by the absence of secondary capilliconidia.