Cladosporium kuwanaspidis X. L. Xu & C. L. Yang, 2025

Cladosporium kuwanaspidis X. L. Xu & C. L. Yang sp. nov.

Fig. 4 View Figure 4

Etymology.

In reference to the generic name for the associated scale insect ( Kuwanaspis howardi ).

Diagnosis.

Similar to Cladosporium perangustum in having conidiophores of comparable size, but C. kuwanaspidis differs by its unbranched conidiophores and larger ramoconidia.

Type.

CHINA • Sichuan Province, Meishan City, Hongya County. Infected scale insects ( Kuwanaspis howardi ) were found on the culms of bamboo ( Pleioblastus amarus (Keng) P. C. Keng ), 29°41.88'N, 103°14.04'E, alt. 540 m, 13 Mar. 2021, C. L. Yang, YCL 202103004 ( SICAU 25-0082 – holotype preserved in the Herbarium of Sichuan Agricultural University; living culture SICAUCC 25-0063 – ex-holotype stored in the Culture Collection in Sichuan Agricultural University) GoogleMaps .

Description.

Parasitic on scale insect from Pleioblastus amarus ( Poaceae ). Sexual morph: Not observed. Asexual morph: Hyphomycetous. Mycelium superficial and immersed, with abundant sporulation on the surface of scale insect. Conidiophores erect, fasciculate, usually macronematous, cylindrical, subnodulose or nodulose, geniculate, septate, unbranched, pale brown to brown, slightly roughened to verruculose, thick-walled, and pronounced loci, 45–120 × 3.5–6 μm. Conidiogenous cells terminal or intercalary, cylindrical, sometimes sinuous, proliferation sympodial, 14–25 (– 80) × 2.5–6.5 μm, conidiogenous loci at the apex (2–5) or in lateral shoulders (0–2). Ramoconidia olive to brown, septate or aseptate, ellipsoidal to subcylindrical, smooth- and thick-walled, 6–13.5 × 3–5.5 μm. Secondary ramoconidia oblong, pale brown, 0–1 septate, 2–4 distal hila, 5.5–9 × 2.5–5 μm. Conidia numerous, catenate, forming short branched chains, aseptate, olive to brown, smooth- and thin- walled, ellipsoid-ovoid, obovoid, 2–7.5 × 2–4 μm. Intercalary conidia limoniform, oval to ellipsoid, with hila protuberant, 3.5–7.5 × 2.5–4 μm. Terminal conidia globose to ellipsoid, sometimes hila evident, 2–4 × 2–3.5 μm. Microcyclic conidiogenesis absent. In vitro on SNA: Mycelium abundant, submerged, overgrowing whole culture dishes, hyphae straight to slightly sinuous, septate and branched, olive to brown, and thick-walled, 2–3.5 µm wide. Conidiophores erect, occasionally branched, brown, thick-walled, 33–118 × 2.5–4 µm. Ramoconidia olive to brown, narrowly ellipsoid to cylindrical-oblong, subcylindrical, septate or aseptate, smooth- and thick-walled, 6–17.5 (– 20) × 2–5 µm. Conidia in simple and branched acropetal chains, light olive, aseptate, smooth- and thin-walled, ellipsoidovoid, obovoid, fusiform, 3–6.5 × 2–4 µm. Intercalary conidia oval to ellipsoid, with hila protuberant, 3.5–6.5 × 2.5–4 μm. Terminal conidia globose to ellipsoid, 2.5–4 × 2–4 μm.

Culture characteristics.

Conidia of all types can germinate within 12 h in sterile distilled water, with germination tubes forming from any part of the conidial body. Colonies on MEA attaining 40–50 mm diameter, after 1 week at 25 ° C, greyish-green to greyish toward regular margins, velvety, sporulation profuse, radially furrowed, aerial mycelium abundant, reverse dark green. Colonies on PDA attaining 35–40 mm diameter, after 1 week at 25 ° C, grey-olivaceous to iron grey, pale greenish grey toward regular margins, reverse dark green. Colonies on SNA attaining 20–30 mm diameter, after 1 week at 25 ° C, smoke-grey to olivaceous-grey, aerial mycelium loose, reverse olivaceous to brown.

Host.

Kuwanaspis howardi ( Diaspididae ).

Habitat.

Subtropical evergreen broad-leaved forests, particularly bamboo forests, are common habitats. Kuwanaspis howardi often causes damage in the lower canopy of bamboo forests. Occasionally, Cladosporium kuwanaspidis can be observed on bamboo culms. Scale insects are more easily found in shaded and sheltered areas.

Distribution.

China, Sichuan Province, Meishan City.

Material examined.

CHINA • Sichuan Province, Meishan City, Hongya County. Infected scale insects ( Kuwanaspis howardi ) were found on the culms of bamboo ( Pleioblastus amarus ), 29°41.88'N, 103°14.04'E, alt. 540 m, 9 Mar. 2021, C. L. Yang, YCL 202103004 (living culture SICAUCC 25-0063 ) GoogleMaps ; • ibid. YCL 202103004-1 ( SICAU 25-0083 , living culture SICAUCC 25-0064 ) GoogleMaps .

Notes.

The ITS base-pair comparison between Cladosporium kuwanaspidis ( SICAUCC 25-0063 ) and the phylogenetically affiliated ex-type culture of C. perangustum (CBS 125996) shows no nucleotide differences. However, nucleotide differences in the act and tef 1 - α regions are 1.86 % (4 bp, 0 gap) and 4.01 % (15 bp, 2 gaps), respectively. Morphologically, C. perangustum has larger ramoconidia compared to those observed in C. kuwanaspidis on both the host and SNA medium (25–45 µm vs. 6–13.5 µm and 6–20 µm, respectively). In addition, compared to the length of intercalary conidia (4–19 µm) observed in C. perangustum (CBS 125996), our isolates exhibit shorter intercalary conidia on both the host and PDA medium (3.5–7.5 µm and 3.5–6.5 µm, respectively) ( Bensch et al. 2010).