Metarhizium lymantriidae Z.H. Chen & L. Xu, 2023

Chen, Zi-Hong, Dai, Yong-Dong, Chen, Kai, Zhang, Yi-Fei, Xu, Ling & Wang, Yuan-Bing, 2023, Papiliomyces puniceum and Metarhizium lymantriidae: two new species from the Gaoligong Mountains in southwestern China, Phytotaxa 594 (1), pp. 53-63 : 59-60

Metarhizium lymantriidae Z.H. Chen & L. Xu , sp. nov. ( Figure 2 )

MycoBank no.: MB 843060

Etymology: Named after the host belonging to the family Lymantriidae (Lepidoptera) .

Colonies on PDA medium reaching 16 mm in diameter after 16 days of cultivation at 25 °C, white to light green. Hyphae septate, hyaline, branched, smooth-walled, 0.9–1.6 (X = 1.2 ± 0.2) µm wide. Phialides cylindrical or ampuliform, smooth-walled, hyaline, 6.9–21.5 × 0.9–1.5 (X = 10.2 ± 4.6 × 1.2 ± 0.2) µm. Conidia oval or ellipsoidal, forming chain in culture, hyaline, aseptate, smooth, 2.1–3.5 × 1.4–2.1 (X = 2.7 ± 0.2 × 1.7 ± 0.2) µm.

Material examined: CHINA. Yunnan Province: the Gaoligong Mountains, on the larva of Lymantriidae , 18 May 2017, Zi-Hong Chen (BUM 818, holotype; KUNCC 4991 , ex-type living culture); Baoshan City, on the larva of Lymantriidae, 24 June 2017, Ling Xu (BUM 830, living culture) .

Notes: Metarhizium lymantriidae was close to M. rileyi and M. dendrolimatilis in the phylogenetic tree. It was difficult to distinguish M. lymantriidae from M. rileyi by the conidia color ( Fig. 2 A, B ). Isolates of M. lymantriidae grew slowly on PDA medium, similar to M. rileyi . M. dendrolimatilis grew moderately faster than M. lymantriidae and M. rileyi . The distinctiveness of M. lymantriidae was indicated by that its conidia size (2.1–3.5 × 1.4–2.1 µm) was smaller than M. rileyi (3.5–4.5 × 2.0–3.1 µm) and M. dendrolimatilis (3.2–5.4 × 2.2–3.2 µm). The phialides of M. lymantriidae (6.9–21.5 × 0.9–1.5 µm) was more slender than M. rileyi (4.7–6.5 × 2.3–3.0 µm) ( Samson 1974) and M. dendrolimatilis (4.3–5.4 × 1.2–3.4 µm). In the wild, M. lymantriidae infected the larva of tussock moth, M. dendrolimatilis infected the larva of Dendrolimus sp. , while M. rileyi could infect the larva of noctuid, beetle and sawfly.

Figures

FIGURE 2. Metarhizium lymantriidae (BUM 818). A. The larva of noctuid infected by the related species, M. rileyi. B. The larva of tussock moth infected by M. lymantriidae. C. Colony on PDA medium, 16 days. D. Colony reverse. E, F. Phialides with conidia chain. G, H. Conidia. I. Hyphae and phialide with budding conidia. Scale bars: A–D = 1 cm, E–I = 5 µm.