Cordyceps cicadae
Cordyceps cicadae (Miq.) Massee, Ann. Bot., Lond. 9: 38 (1895)
Index Fungorum number: IF 311793; Facesoffungi number: FoF 13961
Parasitic on nymph of cicada. Sexual morph: Undetermined. Asexual morph: Synnema single, cylindrical, flesh color, rhizote, unbranched, apically white, powdery due to sporulation. Conidiophores 3–8 (x̄ = 5.9, n = 20) μm in wide, macronematous, apically swollen, forming cellular hyphae where they give rise to metulae. Metulae 4.5–8 (x̄ = 5.6, n = 20) μm, occurring in dense clusters on apical regions of conidiophores, subglobose to globose, thin-walled, bearing groups of phialides. Phialides 4–7 × 2.5–4 (x̄ = 5.4 × 3.3, n = 30) μm, ampulliform, smooth-walled, phialidic. Conidia 5.5–9 × 2–3.5 (x̄ = 7.3 × 2.7, n = 50) μm, hyaline, ellipsoidal, aseptate, guttulate, aggregated in chains.
Culture characteristics – Colonies on PDA reaching 5.3 cm after 30 days at 25 °C, white, powdery, circular, margin entire, reverse white.
Material examined – China, Guizhou Province, Qianxinan Buyei and Miao Autonomous Prefecture, Ceheng County, Gaofeng Villige, on cicada nymph buried in soil, 6 August 2018, De-Ping Wei, GFC 607 (HKAS 102460), living culture KUNCC21-10512.
Molecular data – LSU (OQ127384), SSU (OQ127313), ITS (OQ127350), TEF (OQ186376), RPB1 (OQ186428), RPB2 (OQ186402)
Notes – Our collection nested in a well-supported monophyletic clade consisting of C. lepidopterorum and C. jakajanicola. Cordyceps lepidopterorum was introduced from a lepidopteran larva in Thailand and this species is characterized by forming white colonies on host, isaria-like conidiophores, phialides with globose base, narrow neck and hyaline ellipsoidal conidia (Mongkolsamrit et al. 2018). Cordyceps jakajanicola was described from its sexual and asexual morphs found on a cicada nymph in Thailand (Crous et al. 2019). C. jakajanicola produces white, powdery conidiophores on the terminal part of the stroma, has isaria-like conidiophores, phialides with a globose basal portion, which tapers into a thin neck and ellipsoidal to cylindrical conidia (Crous et al. 2019). Cordyceps jakajanicola was separated from C. lepidopterorum based on the smaller phialides and conidia and the associated hosts. However, in the phylogenetic tree constructed in this study and Crous et al. (2019), these two species have a close affiliation. Notably, the asexual morph of C. jakajanicola is similar with Cordyceps cicadae in the stromal form and the morphology of conidiophores, phialides and conidia. However, the molecular data of C. cicadae was not included in the phylogenetic analysis of Crous et al. (2019), which hindered inference of its phylogenetic relationship with C. jakajanicola. In this study, we have collected a sample whose morphology resembles C. cicadae in all aspects (Kobayasi 1949, Samson 1974, Luangsa-Ard et al. 2005, Zha et al. 2018). Thus, we determined our collection as C. cicadae rather than C. lepidopterorum and C. jakajanicola given that the establishment of the latter two species is not based on sufficient evidence from phylogenetic analysis.
Cordyceps cicadae (HKAS 102460) a Stromata growing from hosts. b Conidiophores. c Phialides. d Conidia. Scale bar: b = 20 μm, c, d, = 5 μm (b–d stained with Congo red solution).
Reference:
Wei DP, Gentekaki E, Wanasinghe DN, Karunarathna SC, Tang SM, Hyde KD 2022 – Diversity, molecular dating and ancestral characters state reconstruction of entomopathogenic fungi in Hypocreales. Mycosphere 13: 281–351.