Cordyceps pruinosa Petch, 1924

Zha, Ling-Sheng, Wen, Ting-Chi, Huang, Shi-Ke, Boonmee, Saranyaphat & Eungwanichayapant, Prapassorn D., 2019, Taxonomy and biology of Cordyceps qingchengensis sp. nov. and its allies, Phytotaxa 416 (1), pp. 14-24 : 21

Cordyceps pruinosa Petch ( Fig. 6 )

= Mariannaea pruinosa Z.Q. Liang

= Phytocordyceps ninchukispora C.H. Su & H.H. Wang

= Cordyceps ninchukispora (C.H. Su & H.H. Wang) G.H. Sung et al.

Notes: —Larvae of Limacodidae (Lepidoptera) live on leaves of many plants at first, then some species crawl into soil to pupate (species pupating on plants cannot be infected by cordyceps). During the process of pupation, once the soil is sufficiently humid, an old larva may easily be infected by ascospores or conidia of C. pruinosa that attach to its body surface. As the pupation proceeds, pupa shell of the insect will gradually be formed, and the insect will at last be killed by the fungus in its pupa shell. When the temperature, humidity and light are suitable for the fungus to grow again (separate from the stage of the previous infection, Wen et al. 2016), fruiting bodies of the fungus will break through the pupa shell. This sexual morph Cordyceps grows slowly; its young fruiting bodies are light yellow, then become pink, followed by reddish orange and finally rust red ( Fig. 6 ).

In moist subtropical regions, C. pruinosa can occur for most of the year. The reasons may include: 1) many Limacodidae species can reproduce 2–3 generations per year; 2) abundant but non-continuous rainfall all year round; and 3) the infection and the growth of cordyceps occur at distinct phases ( Wen et al. 2016).

The pupa shells of Limacodidae are 4–15 mm long, rounded or nearly rounded, dark brown, brown to light yellow, generally their surface is relatively smooth and their texture is relatively hard. Interestingly, many of these pupae are similar to the seeds of the plants on which the insects feed, thus creating an effective imitation mechanism ( Fig. 6 ). C. ninchukispora (≡ Phytocordyceps ninchukispora ), the only exception among all cordyceps species, was reported as a plant pathogen growing on seeds of Beilschmiedia erythrophloia ( Su & Wang 1986) . Beilschmiedia plants are common hosts of several Limacodidae species, and Beilschmiedia seeds are similar to these Limacodidae pupae, so we strongly believe the host of C. ninchukispora is not Beilschmiedia seeds, but Limacodidae pupae.

There are 25 ITS sequences of C. pruinosa and C. ninchukispora in GenBank. Sequence alignment and Blast search indicate that two of them are not cordyceps and four represent other known cordyceps species (>99.6% similarity); the remaining 19 sequences (including one from Taiwan) are>99.5% similar and are probably the same species (the <0.5% base difference mainly comes from base insertions or gaps, which we think are errors during the process of sequence assembly). Cordyceps pruinosa was originally described from Sri Lanka ( Petch 1924) and subsequently reported from Japan ( Kobayasi 1941), China ( Liang 2007), Korea and Thailand ( Sung et al. 2007). Cordyceps ninchukispora was originally reported from Taiwan ( Su & Wang 1986) and this epithet has been commonly used in Thailand. All these collections have the same macroscopic characters, the same hosts ( Limacodidae pupae) and the same geographical distribution (south Asia). The phylogenetic analyses also support that the two species are conspecific ( Figs 1 , 5 ). For these reasons and following the suggestion of Sung et al. (2007), we herein synonymize C. ninchukispora to C. pruinosa . Their apparently different ascospores may be due to observations made at different stages of ascospore development — disarticulated ( Petch 1924, Kobayasi 1941), bifusiform ( Sung et al. 2007) and filiform at first then broken into disarticulated and bifusiform ( Liang 2007).

Figures

FIGURE 1. ML tree of Cordyceps qingchengensis sp. nov. and its allies inferred from a combined SSU, LSU and TEF1-α dataset. Bootstrap support values greater than 70% are indicated above the nodes.

FIGURE 5. NJ tree of Cordyceps qingchengensis and its allies inferred from ITS gene data. Bootstrap values greater than 75% are indicated above the nodes.

FIGURE 6. Different stages of life cycle of Cordyceps pruinosa. a. A larva of Phocoderma betis (Lepidoptera: Limacodidae) killed by C. pruinosa in its pupa shell. b, c. Young fruiting bodies. d. Immature fruiting bodies. e. Mature fruiting bodies. f. Fruiting bodies before dying. Photographs b, c and d represent the same specimen. Specimens were collected in a tea garden (Guizhou, China), and the Phocoderma betis pupae are similar to the seeds of the tea trees.