Research Article |
Corresponding author: Jennifer Luangsa-ard ( jajen@biotec.or.th ) Academic editor: Marc Stadler
© 2019 Kanoksri Tasanathai, Wasana Noisripoom, Thanyarat Chaitika, Artit Khonsanit, Sasitorn Hasin, Jennifer Luangsa-ard.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Tasanathai K, Noisripoom W, Chaitika T, Khonsanit A, Hasin S, Luangsa-ard J (2019) Phylogenetic and morphological classification of Ophiocordyceps species on termites from Thailand. MycoKeys 56: 101-129. https://doi.org/10.3897/mycokeys.56.37636
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Seven new species occurring on termites are added to Ophiocordyceps – O. asiatica, O. brunneirubra, O. khokpasiensis, O. mosingtoensis, O. pseudocommunis, O. pseudorhizoidea and O. termiticola, based on morphological and molecular phylogenetic evidence. O. brunneirubra possesses orange to reddish-brown immersed perithecia on cylindrical to clavate stromata. O. khokpasiensis, O. mosingtoensis and O. termiticola have pseudo-immersed perithecia while O. asiatica, O. pseudocommunis and O. pseudorhizoidea all possess superficial perithecia, reminiscent of O. communis and O. rhizoidea. Phylogenetic analyses based on a combined dataset comprising the internal transcribed spacer regions (ITS) and the largest subunit (LSU) of the ribosomal DNA, partial regions of the elongation factor 1-α (TEF) and the largest and second largest subunits for the RNA polymerase genes (RPB1, RPB2) strongly support the placement of these seven new species in Ophiocordyceps.
Entomopathogenic fungi, Hypocreales, Isoptera, Ophiocordycipitaceae, Taxonomy
The entomopathogenic genus Ophiocordyceps was established by Petch in 1931. His description was based on four specimens including O. blattae Petch, the type species, occurring on a cockroach collected from Sri Lanka, O. unilateralis (Tul. & C. Tul.) Petch on ants, O. peltata (Wakef.) Petch on Coleoptera larva (Cryptorhynchus sp.) and O. rhizoidea (Höhn.) Petch on Coleoptera larva. The distinction of the genus from Cordyceps Fr. was made due the presence of clavate asci that gradually narrowed to a thickened apex, as opposed to the cylindrical asci in many Cordyceps species. The ascospores in Ophiocordyceps sensu Petch are elongated fusoid, multi-septate that remain whole after discharge.
Only a few species of entomopathogenic fungi have been reported from termites. Currently accepted species include Ophiocordyceps bispora (Stifler) G.H. Sung, J.M. Sung, Hywel-Jones & Spatafora on Macrotermes from Tanzania, O. koningsbergeri (Penz. & Sacc.) G.H. Sung, J.M. Sung, Hywel-Jones & Spatafora, known only from the type locality (Java, Indonesia) (
Termites (Isoptera) are one of the eusocial and soil insects that have successfully evolved since the Cretaceous Period and are classified into 7 families, 14 subfamilies, 280 genera and 2,500 species (
In surveys of entomopathogenic fungi in national parks and community forests collections of termite pathogens, most with superficial perithecia and rarely with immersed perithecia were found. The phenotypic characters of the collections in having wiry and pliant, darkly pigmented stromata identifies them primarily to be members of the Ophiocordycipitaceae, mostly as Ophiocordyceps communis. The aims of this study are (1) to clarify the relationships of these collections to known members of the Ophiocordycipitaceae, (2) to uncover hidden species in O. communis species complex and (3) to describe new taxa to accommodate species diversity in Ophiocordyceps.
Species occurring on termites (Isoptera) were found in the ground. The specimens were excavated carefully so as not to lose the host, which could be buried as deep as 15 cm under the ground and were placed in small plastics boxes before returning to the laboratory for isolation. The materials were examined under a stereomicroscope (OLYMPUS SZ61, Olympus Corporation, Japan). The fertile heads of the specimens containing mature perithecia were carefully placed over the Potato Dextrose Agar plate (PDA; fresh diced potato 200 g, dextrose 20 g, agar 15 g, in 1 litre distilled water). These were placed in a plastic box with moist tissue paper overnight to create a humid chamber. The following morning plates were examined with a stereomicroscope to check the discharged ascospores. Discharged ascospores were examined daily for germination and also for fungal contaminants.
The newly collected specimens were noted and photographed in the field using a digital Nikon D5100 camera and were taken to the laboratory and photographed using an Olympus SZX12 before they were placed in a moist chamber to facilitate ascospore discharge. The colour of the freshly collected specimens and cultures were characterised with the colour standard of the Online Auction Colour Chart. One to two perithecia were removed from the stroma and mounted on a glass slide using lactophenol cotton blue to measure their sizes and shapes, as well as the sizes and shapes of the asci and ascospores. Cultures on PDA, Potato Sucrose Agar plate (PSA: potato 200 g/l, sucrose 20 g/l, calcium carbonate 5g/l, agar 20g/l) and quarter strength Sabouraud Dextrose Yeast Agar (SDYA/4; Difco) were observed using light microscopy (Olympus SZ60, CX 30) daily to check for germination and contamination for 2–3 wks. Colony growth rates and characteristics (colour, texture, pigmentation) under dark/light condition (L:D = 14:10) were recorded and photos were taken using the Nikon D5100 camera.
For micro-morphological description, microscope slide cultures were prepared from a block of media (PDA, PSA and SDYA/4, ca. 5 × 5 mm2) inoculated with the fungus and overlaid by a glass coverslip. The cultures were incubated at 25 °C. Observations, measurements of the conidiogenous cells and conidia of the asexual morphs and photographs were taken with an Olympus DP11 microscope.
Dead termite hosts were identified, based on morphological characteristics, such as mandibulate mouthparts, antennae, shape of head and thoraxes. The identification of dead insects was conducted after pure cultures were acquired. Termites were identified by using the extant families of Isoptera after
Cultivation of fungi for molecular work. – Pure cultures were grown on PDA. After approximately 2 wks, the plates were checked for contaminants and small agar blocks were inoculated into sterile Erlenmeyer flasks containing 50 ml Sabouraud Dextrose Broth (Difco) and incubated for 1–2 wks at 25 °C without shaking. Mycelium was then harvested by filtration and washed several times with sterile distilled water. Filtered mycelium was lyophilised. The material was extracted from mycelium by a modified CTAB method as previously described (
PCR amplification. – Five nuclear loci including the nuc rDNA region encompassing the internal transcribed spacers 1 and 2, along with the 5.8S rDNA (ITS), nuc 28S rDNA (LSU), the translation elongation factor 1-α gene (TEF) and the genes for RNA polymerase II largest (RPB1) and second largest (RPB2) subunits were sequenced. PCR primers used to amplify the gene regions for this study were: ITS5, ITS4 for ITS, LROR and LR7 for LSU (
The DNA sequences, generated in this study, were examined for ambiguous bases using BioEdit 7.2.5 (
Maximum Likelihood (ML) analyses was performed with RAxML-HPC2 on XSEDE v8.2.10 (
List of species and GenBank accession numbers of sequences used in this study.
Species | Strain nr. | Host/Substratum | GenBank accession no. | ||||
---|---|---|---|---|---|---|---|
ITS rDNA | LSU | TEF | RPB1 | RPB2 | |||
Cordyceps kyusyuensis | EFCC 5886 | Lepidoptera | – | EF4688131 | EF4687541 | EF4688631 | EF4689171 |
Cordyceps militaris | OSC 93623 | Lepidoptera | JN0498251 | AY1849661 | DQ5223321 | DQ5223771 | AY5457321 |
Drechmeria gunnii | OSC 76404 | Lepidoptera (pupa) | – | AF3395222 | AY4896162 | AY4896502 | DQ5224262 |
Drechmeria sinensis | CBS 567.95 | Nematoda | AJ2924172 | AF3395452 | DQ5223432 | DQ5223892 | DQ5224432 |
Hirsutella cf. haptospora | ARSEF 2228 | Diptera: Itonididae | KM6521663 | KM6521183 | KM6520013 | KM6520413 | – |
Hirsutella citriformis | ARSEF 1446 | Hemiptera; Cixiidae | KM6521543 | KM6521063 | KM6519903 | KM6520313 | – |
ARSEF 1035 | Hemiptera; Cixiidae | KM6521533 | KM6521053 | KM6519893 | KM6520303 | – | |
Hirsutella cryptosclerotium | ARSEF 4517 | Hemiptera; Pseudococcidae | KM6521573 | KM6521093 | KM6519923 | KM6520323 | – |
Hirsutella fusiformis | ARSEF 5474 | Coleoptera: Curculionidae | – | KM6521103 | KM6519933 | KM6520333 | – |
Hirsutella gigantea | ARSEF 30 | Hymenoptera: Pamphiliidae | – | – | JX5669803 | KM6520343 | – |
Hirsutella haptospora | ARSEF 2226 | Acari: Uropodina | KM6521593 | – | KM6519953 | KM6520363 | – |
Hirsutella illustris | ARSEF 5539 | Hemiptera: Aphididae | KM6521603 | KM6521123 | KM6519963 | KM6520373 | – |
Hirsutella lecaniicola | ARSEF 8888 | Hemiptera: Coccidae | KM6521623 | KM6521143 | KM6519983 | KM6520383 | – |
Hirsutella liboensis | ARSEF 9603 | Lepidoptera: Cossidae | KM6521633 | KM6521153 | – | – | – |
Hirsutella necatrix | ARSEF 5549 | Acari | KM6521643 | KM6521163 | KM6519993 | KM6520393 | – |
Hirsutella nodulosa | ARSEF 5473 | Lepidoptera; Pyralidae | KM6521653 | KM6521173 | KM6520003 | KM6520403 | – |
Hirsutella radiata | ARSEF 1369 | Diptera | – | KM6521193 | KM6520023 | KM6520423 | – |
Hirsutella repens nom. inval. | ARSEF 2348 | Hemiptera: Delphacidae | KM6521673 | KM6521203 | KM6520033 | – | – |
Hirsutella rhossiliensis | ARSEF 2931 | Tylenchida: Heteroderidae | KM6521683 | KM6521213 | KM6520043 | KM6520433 | – |
Hirsutella satumaensis | ARSEF 996 | Lepidoptera: Pyralidae | KM6521723 | KM6521253 | KM6520083 | KM6520473 | – |
Hirsutella sp. | ARSEF 8378 | Hemiptera: Cixiidae | – | KM6521273 | KM6520103 | KM6520493 | – |
Hirsutella strigosa | ARSEF 2197 | Hemiptera: Cicadellidae | KM6521753 | KM6521293 | KM6520123 | KM6520503 | – |
ARSEF 2044 | Hemiptera: Delphacidae | KM6521743 | KM6521283 | KM6520113 | – | – | |
Hirsutella subulata | ARSEF 2227 | Lepidoptera: Microlepidoptea | KM6521763 | KM6521303 | KM6520133 | KM6520513 | – |
Hirsutella thompsonii | ARSEF 257 | Acari; Eriophyidae | KM6521823 | KM6521363 | KM6520193 | KM6520543 | – |
ARSEF 414 | Acari; Eriophyidae | KM6521843 | KM6521393 | KM6520213 | KM6520563 | – | |
ARSEF 3323 | Acari: Tenuipalpidae | KM6521883 | KM6521433 | KM6520243 | KM6520593 | – | |
ARSEF 3482 | KM6521893 | KM6521443 | KM6520253 | KM6520603 | – | ||
ARSEF 253 | Acari: Eriophyidae | KM6521793 | KM6521333 | KM6520163 | – | – | |
ARSEF 256 | Acari: Eriophyidae | KM6521813 | KM6521353 | KM6520183 | KM6520533 | – | |
ARSEF 258 | Acari: Eriophyidae | – | KM6521373 | KM6520203 | KM6520553 | – | |
ARSEF 2800 | Acari | KM6521873 | KM6521423 | KM6520233 | KM6520583 | – | |
Hirsutella thompsonii “var. synnematosa” | ARSEF 1947 | Acari: Tarsonemidae | KM6521913 | KM6521463 | KM6520263 | – | – |
ARSEF 5412 | Acari: Tetranychidae | KM6521933 | KM6521483 | – | – | – | |
Hirsutella thompsonii var. vinacea | ARSEF 254 | Acari: Eriophyidae | KM6521943 | KM6521493 | KM6520283 | KM6520623 | – |
Hirsutella versicolor | ARSEF 1037 | Hemiptera: Membracidae | – | KM6521503 | KM6520293 | KM6520633 | – |
Ophiocordyceps acicularis | OSC 110988 | Coleoptera (larva) | – | EF4688042 | EF4687452 | EF4688532 | – |
OSC 110987 | Coleoptera (larva) | – | EF4688052 | EF4687442 | EF4688522 | – | |
Ophiocordyceps agriotidis | ARSEF 5692 | Coleoptera (larva) | JN0498192 | DQ5187542 | DQ5223222 | DQ5223682 | DQ5224182 |
Ophiocordyceps aphodii | ARSEF 5498 | Coleoptera | – | DQ5187552 | DQ5223232 | – | DQ5224192 |
Ophiocordyceps appendiculata | NBRC 106960 | Coleoptera (larva) | JN9433262 | JN9414132 | – | JN9924622 | – |
Ophiocordyceps asiatica | BCC 30516 | Termitidae (adult termite) | MH754722 | MH753675 | MK284263 | MK214105 | MK214091 |
BCC 86435 | Termitidae (adult termite) | MH754723 | MH753676 | – | MK214106 | MK214092 | |
Ophiocordyceps communis | BCC 1842 | Termitidae (adult termite) | MH754726 | MH753680 | MK284266 | MK214110 | MK214096 |
BCC 1874 | Termitidae (adult termite) | MH754725 | MH753679 | MK284267 | MK214109 | MK214095 | |
BCC 2754 | Termitidae (adult termite) | MH754727 | MH753681 | MK284268 | MK214111 | MK214097 | |
Ophiocordyceps brunneipunctata | OSC 128576 | Coleoptera (Elateridae larva) | – | DQ5187562 | DQ5223242 | DQ5223692 | DQ5224202 |
Ophiocordyceps brunneirubra | BCC 14384 | Termitidae (adult termite) | MH754736 | MH753690 | GU797121 | MK751465 | MK751468 |
BCC 14478 | Termitidae (adult termite) | MH754734 | MH753688 | GU797122 | MK751466 | MK214102 | |
BCC 14477 | Termitidae (adult termite) | MH754735 | MH753689 | GU797123 | MK751467 | MK214103 | |
Ophiocordyceps dipterigena | OSC 151911 | Diptera (adult fly) | – | KJ8788864 | KJ878966 4 | KJ8790004 | – |
Ophiocordyceps elongata | OSC 110989 | Lepidoptera (larva) | – | EF4688082 | EF4687482 | EF4688562 | – |
Ophiocordyceps gracilioides | HUA 186095 | Coleoptera (Elateridae larva) | – | – | KM4119942 | KP2129142 | – |
HUA 186092 | Coleoptera (Elateridae larva) | – | KJ1309922 | – | KP2129152 | – | |
Ophiocordyceps gracilis | EFCC 8572 | Lepidoptera (larva) | JN0498512 | EF4688112 | EF4687512 | EF4688592 | EF4689122 |
EFCC 3101 | Lepidoptera (larva) | – | EF4688102 | EF4687502 | EF4688582 | EF4689132 | |
Ophiocordyceps granospora | BCC 82255 | Hymenoptera (Polyrhachis sp.) | MH0281434 | MH0281564 | MH0281834 | MH028164 | MH028174 |
Ophiocordyceps heteropoda | EFCC 10125 | Hemiptera (cicada nymph) | JN0498522 | EF4688122 | EF4687522 | EF4688602 | EF4689142 |
Ophiocordyceps irangiensis | BCC 82793 | Hymenoptera (Polyrhachis illaudata) | MH0281414 | – | MH0281854 | MH0281634 | MH028174 |
BCC 82795 | Hymenoptera (Polyrhachis sp.) | MH0281424 | – | MH0281864 | MH0281644 | MH028174 | |
Ophiocordyceps khaoyaiensis | BCC 82796 | Hymenoptera (Polyrhachis armata) | MH0281504 | MH0281534 | MH0281874 | MH0281654 | MH028174 |
BCC 82797 | Hymenoptera (Polyrhachis armata) | MH0281514 | MH0281544 | MH0281884 | MH0281664 | MH028174 | |
Ophiocordyceps khokpasiensis | BCC 48071 | Termitidae (adult termite) | MH754728 | MH753682 | MK284269 | MK214112 | – |
BCC 48072 | Termitidae (adult termite) | MH754729 | MH753683 | MK284270 | MK214113 | – | |
BCC 1764 | Termitidae (adult termite) | MH754730 | MH753684 | MK284271 | MK214114 | MK214098 | |
Ophiocordyceps konnoana | EFCC 7315 | Coleoptera (larva) | – | – | EF4687532 | EF4688612 | EF4689162 |
Ophiocordyceps longissima | NBRC 108989 | Hemiptera (cicada nymph) | AB9684071 | AB9684211 | AB9685851 | – | – |
EFCC 6814 | Hemiptera (cicada nymph) | – | EF4688172 | EF4687572 | EF4688652 | – | |
Ophiocordyceps mosingtoensis | BCC 30904 | Termitidae (adult termite) | MH754732 | MH753686 | MK284273 | MK214115 | MK214100 |
BCC 36921 | Termitidae (adult termite) | MH754731 | MH753685 | MK284272 | MK214116 | MK214099 | |
Ophiocordyceps myrmecophila | CEM 1710 | Hymenoptera (Adult ant) | – | KJ8788944 | KJ8789744 | KJ8790084 | – |
Ophiocordyceps myrmicarum | ARSEF 11864 | Hymenoptera: Formicidae | – | – | JX5669733 | KJ6801513 | – |
Ophiocordyceps nigrella | EFCC 9247 | Lepidoptera (larva) | JN0498532 | EF4688182 | EF4687582 | EF4688662 | EF4689202 |
Ophiocordyceps pseudocommunis | BCC 16757 | Termitidae (adult termite) | MH754733 | MH753687 | MK284274 | MK214117 | MK214101 |
Ophiocordyceps pseudocommunis | NHJ 12581 | Termitidae (adult termite) | – | EF4688313 | EF4687753 | – | EF4689303 |
NHJ 12582 | Termitidae (adult termite) | – | EF4688303 | EF4687713 | – | EF4689263 | |
Ophiocordyceps pseudorhizoidea | BCC 48879 | Termitidae (adult termite) | MH754720 | MH753673 | MK284261 | MK214104 | MK214089 |
BCC 86431 | Termitidae (adult termite) | MH754721 | MH753674 | MK284262 | MK751469 | MK214090 | |
NHJ 12522 | Termitidae (adult termite) | JN0498572 | EF4688252 | EF4687642 | EF4688732 | EF4689232 | |
NHJ 12529 | Termitidae (adult termite) | – | EF4688242 | EF4687652 | EF4688722 | EF4689222 | |
Ophiocordyceps pulvinata | TNS-F-30044 | Hymenoptera | – | – | GU9042095 | GU9042105 | – |
Ophiocordyceps ravenelii | OSC 110995 | Coleoptera (larva) | – | DQ5187642 | DQ5223342 | DQ5223792 | – |
Ophiocordyceps robertsii | KEW 27083 | Lepidoptera (Hepialidae larva) | – | EF4688262 | EF4687662 | – | – |
Ophiocordyceps satoi | J7 | Hymenoptera (Polyrhachis lamellidens) | – | KX7135995 | KX7136835 | KX7137115 | – |
J19 | Hymenoptera (Polyrhachis lamellidens) | – | KX7136015 | KX7136845 | KX7137105 | – | |
Ophiocordyceps sinensis | ARSEF 6282 | Lepidoptera; Hepialidae | KM6521733 | KM6521263 | KM6520093 | KM6520483 | – |
EFCC 7287 | Lepidoptera; Hepialidae (larva) | JN0498542 | EF4688272 | EF4687672 | EF4688742 | EF4689252 | |
Ophiocordyceps sobolifera | KEW 78842 | Hemiptera (cicada nymph) | JN0498552 | EF4688282 | – | EF4688752 | DQ5224322 |
Ophiocordyceps spataforae | NHJ 12525 | Hemiptera | – | EF4690786 | EF4690636 | EF4690926 | EF4691116 |
OSC 128575 | Hemiptera | – | EF4690796 | EF4690646 | EF4690936 | EF4691106 | |
Ophiocordyceps sphecoceplala | NBRC 101416 | Hymenoptera (adult wasp) | – | JN9414434 | – | JN9924324 | – |
Ophiocordyceps stylophora | OSC 111000 | Coleoptera; Elateridae (larva) | JN0498282 | DQ5187662 | DQ5223372 | DQ5223822 | – |
Ophiocordyceps termiticola | BCC 1920 | Termitidae (adult termite) | MH754724 | MH753678 | MK284265 | MK214108 | MK214094 |
BCC 1770 | Termitidae (adult termite) | GU723780 | MH753677 | MK284264 | MK214107 | MK214093 | |
Ophiocordyceps unilateralis | OSC 128574 | Hymenoptera | – | DQ5187682 | DQ5223392 | DQ5223852 | DQ5224362 |
Ophiocordyceps xuefengensis | GZUHHN 13 | Lepidoptera; Phassus nodus (larva) | KC6318042 | – | KC6317902 | KC6317952 | – |
Ophiocordyceps yakusimensis | HMAS 199604 | Hemiptera; (cicada nymph) | – | KJ8789022 | – | KJ8790182 | KJ8789532 |
Purpureocillium lilacinum | CBS 284.36 | Soil | AY6241892 | – | EF4687922 | EF4688982 | EF4689412 |
CBS 431.87 | Nematoda | AY6241882 | EF4688442 | EF4687912 | EF4688972 | EF4689402 |
We obtained 96 new sequences from 20 specimens (Table
The ML and BI analyses displayed similar topologies resolving seven new species in Ophiocordyceps (Fig.
Phylogenetic tree based on combined data set of ITS, LSU, TEF, RPB1 and RPB2 sequences showing the relationship of seven new species on termites from Thailand with other species of Ophiocordyceps. Numbers above lines at significant nodes represent Maximum Likelihood bootstrap values, Bayesian posterior probabilities and MP bootstrap values. Bold lines mean support for the tree analyses were 100%.
THAILAND. Nakhon Ratchasima Province, Khao Yai National Park; 14°711'N, 101°421'E; on termite; 21 May 2008; K. Tasanathai, S. Mongkolsamrit, B. Thongnuch, P. Srikitikulchai, R. Ridkaew, A. Khonsanit (holotype BBH 38718 dried culture; ex-type living culture, BCC 30516). GenBank: ITS = MH754722, LSU = MH753675, TEF = MK284263, RPB1 = MK214105, RPB2 = MK214091
Ophiocordyceps asiatica (BBH38718, BCC30516) A stroma of fungus emerging from termite B phialide on specimen C part of stroma showing perithecia D perithecium E asci F ascospores G colony on PDA at 20 d obverse and reverse H, I phialides with conidia on PDA J, K conidium L colony on PSA at 20 d obverse and reverse M, N phialides with conidia on PSA O conidium P colony on SDYA/4 at 20 d obverse and reverse Q, R phialides with conidia S conidia T–X scanning electron micrographs of phialides with conidia on PDA. Scale bars: 10 mm (A, G, L, P); 5 μm (B); 1 mm (C); 8 μm (D); 15 μm (E); 10 μm (F, I); 3 μm (H, J, K, M, N, S, T, V); 2 μm (O, Q, R, U, W, X).
‘asiatica’ referring to Asia.
Stroma solitary, simple, filiform, up to 15 cm long, 1 mm wide, orange-brown (oac48-50), ca. 10 cm emerging above leaf litter, 5 cm buried in the soil. Asexual state (Hirsutella) produced at the terminal part of the stroma, ca. 2 cm long, light brown to grey. Perithecia superficial covering middle part of stroma, globose to subglobose, (240–)261.5–302(–320) × (180–)205–240.5(–260) µm. Asci 8-spored, filiform, (92.5–)104–143.5(–175) × 5–6.5 µm with cap, 2 × 2 µm. Ascospores whole, filiform, (80–)100–122.5(–132.5) × 1–2 µm, with septate. Asexual state Hirsutella, phialides arising singly or laterally from the hyphae along the terminal part of the stroma, (9–)9.5–13(–15) × (3–)3.5–4.8(–5) µm, conidia hyaline, fusiform, 4–5×2–3 µm.
Colonies on PDA, attaining a diam. of 27 mm after 20 d at 25 °C, mycelium sparse to abundant, grey in the middle to pale brown. Conidiogenous cells developing directly on the aerial mycelium, swollen towards the base, hyaline, smooth, tapering gradually towards the apex, which often forms a thin warty neck (1 µm), monophialidic or rarely polyphialidic 15–18.5(–20) × 2–3 µm µm. Conidia aseptate, hyaline, smooth, arising from phialides at the apex of each neck, fusiform, (7–)7.6–9 × 2–3 µm, with a mucous sheath.
Colonies on PSA, attaining a diam. of 25 mm after 20 d at 25 °C, Conidiogenous cells swollen towards the base, hyaline, smooth, tapering gradually towards the apex, which often forms a thin neck, monophialidic, (15–)17–21(–23) × 3–4 µm. Conidia aseptate, hyaline, smooth, arising from phialides at the apex of each neck, fusiform, (6–)6.5–8.5(–10) × 2–3 µm, with a mucous sheath.
Colonies on SDYA/4, slow-growing, attaining a diam. of 30 mm after 20 d at 25 °C. Conidiogenous cells swollen towards the base, hyaline, smooth, tapering gradually towards the apex, which often forms a thin neck, monophialidic or polyphialidic, (10–)12–15(–17) × (2–)2.5–3 µm. Conidia aseptate, hyaline, smooth, arising from phialides at the apex of each neck, fusiform, (7–)8.5–11.5(–13) × 2–3 µm, with a mucous sheath.
Thailand, only known from Khao Yai National Park.
Parasitic on a pair of termites from a reproductive caste (Order Isoptera: Family Termitidae, Subfamily Macrotermitinae) and these specimens were buried in the soil. The fungus emerged from the segment between the prothorax and mesothorax of one of the termite pairs.
THAILAND. Saraburi Province, Khao Yai National Park; 14°586'N, 100°998'E; on termite; 4 June 2017; S. Mongkolsamrit, U. Pinruan, P. Srikitikulchai, R. Promharn, S. Sommai (BBH45363, BBC86435).
Four species, O. asiatica, O. communis, O. pseudocommunis and O. pseudorhizoidea look morphologically similar in having superficial perithecia and long wiry, pliant stroma emerging from the ground. In O. asiatica and O. communis, the stroma is dark brown, while in O. pseudocommunis and O. pseudorhizoidea it is cream to light brown. The perithecia in O. communis, O. pseudocommunis and O. pseudorhizoidea are larger than O. asiatica, but its ascospores are larger than in O. pseudorhizoidea.
THAILAND. Uthai Thani Province, Huai Kha Khaeng Wildlife Sanctuary; 15°605'N, 99°330'E; on termite; 28 August 2003; N.L. Hywel-Jones (holotype BBH 9008 dried culture; ex-type living culture: BCC14478). GenBank: ITS = MH754734, LSU = MH753688, TEF = GU797122, RPB1 = MK751466, RPB2 = MK214102
Ophiocordyceps brunneirubra (BBH 9008, BCC14478) A, B fungus on termite C part of stroma showing perithecia D immersed perithecia E asci F ascospore G, H colony on PDA at 20 d (G) colony obverse (H) colony reverse I, J, K phialides with conidia on PDA L, M conidia on PDA N, P, O sclerotia formed in culture Q, R, S scanning electron micrographs of phialides with conidia T, U colony on PSA at 20 d (T) colony obverse (U) colony reverse V, W, X phialides with conidia on PSA Y conidia on PSA. Scale bars: 25 mm (A); 15 mm (B, G, H, T, U); 1 mm (C); 130 μm (D); 10 μm (I, Q, W); 15 μm (J); 3 μm (K, R); 5 μm (L); 4 μm (M, S, Y); 6 μm (V); 7 μm (X).
‘brunneirubra’ referring to the reddish-brown appearance of the fertile head.
Stroma solitary, simple or branched, narrowly clavate, slender and wiry, up to 9.5 cm long, 0.5 mm wide. Fertile head cylindric, orange brown (oac642) to red brown (oac635), up to 8 mm long, 1 mm wide. Perithecia immersed, ovoid, ordinal in arrangement, (300–)334.5–400(–403) × (130–)138.5–178(–200) µm. Asci 8-spored, cylindrical, (155–)176–214.5(–225) × 4.5–7(–8) µm. Ascospores whole, filiform, 156.5–197.5 × 2–3 µm, with septa.
Colonies on PDA, attaining a diam. of 25 mm within 20 d at 25 °C, orange (oac651) to orange brown (oac639). Conidiogenous cells monophialidic, arising from hyphae laterally or terminally, hyaline, tapering gradually or abruptly into a long slender neck, (32–)35.5–43.5(–50) µm long, (2–)2.5–3µm wide at the base, 1–1.5 µm wide at tip with warty surface. Conidia hyaline, one-celled, with a distinct gold cap covering the tip of the conidia, fusiform, (12–)13.5–15.5(–17) × 2–3 (–4) µm. Sclerotia formed in culture after 1 month, dark brown (oac635).
Colonies on PSA, attaining a diam. of 25 mm within 20 d at 25 °C, orange brown (oac716) to brown (oac721), reverse orange brown (oac721). Conidiogenous cells monophialidic, arising from hyphae laterally or terminally, hyaline, tapering gradually or abruptly into a long slender neck, (30–)32.5–39.5(–41) µm long, (2–)2.5–3.5(–4) µm wide at the base, 1–1.5 µm wide at tip with warty surface. Conidia hyaline, one-celled, arising from phialides, with a distinct gold cap covering the tip of the conidia, fusiform, (13–)14–16(–17) × 2–3 µm.
Colonies on SDYA/4, attaining a diam. of 25 mm within 20 d at 25 °C, dark brown (oac733), reverse orange brown (oac728). Conidiogenous cells monophialidic, arising from hyphae laterally or terminally, hyaline, tapering gradually or abruptly into a long slender neck, 25–40 µm long, 2–4 µm wide at the base, 1 µm wide at tip with warty surface. Conidia hyaline, one-celled, arising from phialides, with a distinct gold cap covering the tip of the conidia, fusiform, 12–15 × 2–3 µm.
Thailand, only known from Huai Kha Kaeng Wildlife Sanctuary.
Parasitic on a subterranean termite (Order Isoptera: Family Termitidae, Subfamily Macrotermitinae), collected from the soil. These termites belong to the reproductive caste (king or queen alates). The fungus emerged from between head and thoraxes of termite alates.
THAILAND. Uthai Thani Province, Huai Kha Khaeng Wildlife Sanctuary; at 15°605'N, 99°330'E; on termites; 28 Aug 2003; N.L. Hywel-Jones (BBH9009, BCC14477), (BBH9005, BCC14384).
This species differs from other species on termites collected in Thailand in being singly infected by fungus instead of termite pairs and having immersed perithecia and red brown fertile terminal stroma. The species is not commonly found since it could easily be mistaken as a plant material sprouting from the ground. It is reminiscent of O. brunneipunctata but only on a different host. The shape of the conidia, like a banana with a hat or a cap, has never been seen in any kind of fungal spore morphology before.
THAILAND. Kalasin Province, Phu Si Than Wildlife Sanctuary, Khok Pa Si Community Forest; 16°562'N, 104°103'E; on termite; 14 June 2011; K. Tasanathai, P. Srikitikulchai, A. Khonsanit, K. Sansatchanon, W. Noisripoom (holotype BBH32173 dried culture; ex-type living culture: BCC48071). GenBank: ITS = MH754728, LSU = MH753682, TEF = MK284269, RPB1 = MK214112
Ophiocordyceps khokpasiensis (BBH32173, BCC48071) A fungus on termite B part of stroma showing perithecia C pseudo-immersed perithecia D asci E ascospore F phialides with conidia from synnema G conidia from synnema H colony on PDA at 20 d colony obverse and reverse I, J phialides with conidia on PDA K, L conidium M, N, O scanning electron micrographs of phialides with conidia on PDA P colony on PSA at 20 d obverse and reverse Q, R, S phialides with conidia on PDA T, U conidium V colony on SDYA/4 at 20 d obverse and reverse W, X, Y phialides with conidia Z conidium. Scale bars: 2.5 cm (A); 1 mm (B); 100 µm (C); 5 µm (D, G, I, J, K, L); 20 µm (E); 6 µm (F); 7 mm (H, P, V); 3 µm (M, N, O, Q, R, S, T, U); 4 µm (W, X, Y); 2 µm (Z).
‘khokpasiensis’ referring to Khok Pa Si community forest, site of collection of type species.
Stroma solitary, simple, cylindrical, 16 cm long, 1 mm wide, brown (oac48-50), ca. 5.5 cm emerging above the leaf litter, ca. 10.5 cm buried in the soil. Asexual state (Hirsutella) produced ca. 1.5 cm at the terminal part of the stroma, light brown to grey. Perithecia pseudo-immersed, subglobose to broadly ellipsoidal, covering middle part of stroma, (200–)214–248.5(–250) × (120–)140–186(–200) µm. Asci 8-spored, filiform, (62.5–)86–115(–125) × 4–5 µm. Ascospores whole, filiform, (46–)51–74(–90) × 2–3 µm. Asexual state Hirsutella, phialides arising singly or laterally from the hyphae along the terminal part of the stroma, (8–)9–11(–12) × 3–4 µm. Conidia, hyaline, oval, 5–6.5(–7) × 2–3 µm.
Colonies on PDA, attaining a diam. of 25.5 mm within 20 d at 25 °C, cream (oac900) to grey (oac893). Conidiogenous cells swollen towards the base, hyaline, smooth, tapering gradually towards the apex, which often forms a thin neck, monophialidic or polyphialidic, (15–)16.5–23(–28) × 3–4.5(–5) µm. Conidia arising from phialides at the apex of each neck, globose to oval, one-celled (4–)4.5–5.5(–6) × 2.5–4 µm, embedded in a mucous sheath.
Colonies on PSA, attaining a diam. of 24 mm within 20 d at 25 °C, white to grey (oac843). Conidiogenous cells swollen towards the base, hyaline, smooth, tapering gradually towards the apex, which often forms a thin neck, monophialidic or polyphialidic, (14–)15.5–22.5(–28) × 3–4.5(–5) µm. Conidia arising from phialides at the apex of each neck, globose to oval, one-celled 4–5(–6) × (2–)2.5–3.5(–5) µm, embedded in a mucous sheath.
Colonies on SDYA/4, attaining a diam. of 25 mm within 20 d at 25 °C, grey to brown (oac473). Conidiogenous cells swollen towards the base, hyaline, smooth, tapering gradually towards the apex, which often forms a thin neck, monophialidic or polyphialidic, (9–)11.5–15.5(–19) × (2–)3–3.5(–4) µm. Conidia arising from phialides at the apex of each neck, globose to oval, one celled 3.5–4.5(–5) × 2.5–3 (–3.5) µm, embedded in a mucous sheath.
North-eastern Thailand.
Parasitic on a pair of termites from a reproductive caste (Order Isoptera: Family Termitidae, Subfamily Macrotermitinae) and these specimens were buried in the soil. The fungus emerged from the segment between the prothorax and mesothorax of one of the termite pairs.
THAILAND. Saraburi Province, Namtok Samlan National Park (Phra Buddha Chai); 14°526'N, 100°9'E; on termite; 15 June 1996; Hywel-Jones, NL (BBH5116, BCC1764). Kalasin Province: Phu Si Than Wildlife Sanctuary, Khok Pa Si Community Forest; 16°562'N, 104°103'E; on termite; 14 June 2011; K. Tasanathai, P. Srikitikulchai, A. Khonsanit, K. Sansatchanon, W. Noisripoom (BBH32173, BCC48072).
Other Ophiocordyceps species reported on termites with pseudo-immersed perithecia are O. mosingtoensis and O. termiticola. O. khokpasiensis and O. termiticola shares similarity in the colour of the perithecia but in O. termiticola, the perithecia are denser while it is loosely arranged in O. khokpasiensis. O. mosingtoensis produces a more robust stroma compared to O. khokpasiensis and O. termiticola. The gross morphology of O. khokpasiensis is similar to O. asiatica, O. communis, O. pseudocommunis and O. pseudorhizoidea. However, all these other species produce superficial perithecia.
THAILAND. Nakhon Ratchasima Province, Khao Yai National Park; 14°711'N, 101°421'E; on termite; 17 June 2009; K. Tasanathai, P. Srikitikulchai, S. Mongkolsamrit, T. Chohmee, R. Ridkaew, N.L. Hywel-Jones (holotype BBH26809 dried culture; ex-type living culture, BCC36921). GenBank: ITS = MH754731, LSU = MH753685, TEF = MK284272, RPB1 = MK214116, RPB2 = MK214099
Ophiocordyceps mosingtoensis (BBH26809, BCC36921) A stroma of fungus emerging from termite B part of stroma showing perithecia C pseudo-immersed perithecia D, E ascus F ascospore G, L, Q, V scanning electron micrographs of phialides with conidia on PDA H colony on PDA at 20 d obverse and reverse I, J phialides with conidia K conidium M colony on PSA at 20 d obverse and reverse N, O phialides with conidia P conidium R colony on SDYA/4 at 20 d obverse and reverse S, T phialides with conidia U conidium. Scale bars: 10 mm (A); 1 mm (B); 150 µm (C); 25 µm (D); 4 µm (E); 30 µm (F); 10 µm (G); 8 mm (H, M, R); 3 µm (I, J, N, O, S, T); 2 µm (K, L, P, Q, U); 1 µm (V).
‘mosingtoensis’ referring to name after the type locality.
Stroma solitary, simple, cylindrical, up to 11 cm long, 1 mm wide, brown (oac 48-50), ca. 8.5 cm emerging above the leaf litter, ca. 2.5 cm buried in the soil. Asexual state (Hirsutella) produced ca. 1 cm at the terminal part of the stroma, light brown to grey. Perithecia pseudo-immersed, broadly ovoid covering middle part of stroma, (400–)414–469 (–500) × (200–)208–263(–300) µm. Asci 8-spored, filiform, (187.5–) 217–265(–287.5) × 4.5–6.5(–7.5) µm with cap, 2 µm. Ascospores whole, filiform, (230–)240–291(–315) × 1.5–3 µm, with septa.
Colonies on PDA, attaining a diam. of 16 mm within 20 d at 25 °C, cream (oac872) to grey (oac909). Conidiogenous cells swollen towards the base, hyaline, smooth, tapering gradually towards the apex, which often forms a thin neck, monophialidic, (10–)12.5–16 (–17) × (2–) 2.5–3 µm. Conidia arising from phialides at the apex of each neck, oval, 3–4.5(–5) × 2–2.5(–3) µm.
Colonies on PSA, attaining a diam. of 17 mm within 20 d at 25 °C, white to grey (oac872). Conidiogenous cells swollen towards the base, hyaline, smooth, tapering gradually towards the apex, which often forms a thin neck, monophialidic, (10–)11.5–15(–17) × (2–)2.5–3.5(–4) µm. Conidia arising from phialides at the apex of each neck, oval, (3–)3.5–5(–5.5) × 2–3 µm.
Colonies on SDYA/4, attaining a diam. of 17 mm within 20 d at 25 °C, white to grey (oac802). Conidiogenous cells swollen towards the base, hyaline, smooth, tapering gradually towards the apex, which often forms a thin neck, monophialidic or polyphialidic, (9–)10.5–14.5(–17) × (2–)2.5–3 µm. Conidia arising from phialides at the apex of each neck, oval, (3–)3.5–4.5(–5) × 2–3 µm.
Thailand, only known from Khao Yai National Park.
Parasitic on a pair of termites from a reproductive caste (Order Isoptera: Family Termitidae, Subfamily Macrotermitinae) and these specimens were buried in the soil. The fungus emerged from the segment between the prothorax and mesothorax of one of the termite pairs.
THAILAND. Nakhon Ratchasima Province, Khao Yai National Park; 14°711'N, 101°421'E; on termite; 18 June 2008; J.J. Luangsa-ard, K. Tasanathai, S. Mongkolsamrit, B. Thongnuch, P. Srikitikulchai, R. Ridkaew (BBH 23860, BCC 30904).
O. mosingtoensis has a sturdier, robust stroma compared with O. termiticola and O. khokpasiensis which also produce pseudo-immersed perithecia.
THAILAND. Nakhon Nayok Province, Khao Yai National Park; 14°163'N, 101°268'E; on termite; 13 July 2004; S. Sivichai, K. Tasanathai, N. Boonyuen, P. Puyngain (holotype BBH10001 dried culture; ex-type living culture, BCC16757). GenBank: ITS = MH754733, LSU = MH753687, TEF = MK284274, RPB1 = MK214117, RPB2 = MK214101
Ophiocordyceps pseudocommunis (BBH10001, BCC16757) A stroma of fungus emerging from termite B part of stroma showing superficial perithecia C perithecium D ascospore E phialides with conidia from synnema F conidia from synnema G, L, M, N, O, P scanning electron micrographs of phialides with conidia on PDA H colony on PDA at 20 d obverse and reverse I, J phialides with conidia on PDA K conidium Q colony on PDA at 20 d obverse and reverse R phialides with conidia on PSA S conidium T colony on SDYA/4 at 20 d obverse and reverse U phialides with conidia V conidium. Scale bars: 10 mm (A); 0.5 mm (B); 150 µm(C); 6 µm (D); 7 µm (E); 2 µm (F); 4 µm (G); 8 mm (H, Q, T); 8 µm (I); 5 µm (J, K, U, V); 3 µm (R, S).
‘pseudocommunis’ referring to close affinity to Ophiocordyceps communis.
Stroma solitary, simple, cylindrical, 21.5 cm long, 0.5 mm wide, brown (oac48-50), ca. 12 cm emerging above the leaf litter, ca. 9 cm buried in the soil. Asexual state (Hymenostilbe-like) produced ca. 5 cm at the terminal part of the stroma, light brown to brown. Perithecia superficial, subglobose, covering middle part of the stroma, (520–)536.5–596.5(–600) × (360–)373.5–425 (–440) µm. Asci, 8-spored, filiform, 160–164.5(–165) × 14–17 µm. Ascospores whole, filiform, (107.5–)120.5–138 (–147.5) × (6–)6.5–7 (7.5) µm, with 7–8 septa. Asexual state Hymenostilbe-like, conidiogenous cells forming a compact hymenium-like layer and had two to four denticles at their apices, cylindrical to clavate, (17–)18.5–21(–22) × (2–)2.5–7.5(–8) µm. Conidia, hyaline, fusiform, (6–)6.5–7.5(–8) × 2–3 µm.
Colonies on PDA, attaining a diam. of 26.5 mm within 20 d at 25 °C, white (oac909) to grey (oac851). Conidiogenous cells arising from hyphae laterally or terminally, hyaline, tapering gradually or abruptly into a long slender neck. Conidia hyaline, septate (2–3), arising from phialides at the apex of each neck, fusiform, (13–)14.5–20.5(–27) × (3–)3.5–5 µm.
Colonies on PSA, attaining a diam. of 15 mm within 20 d at 25 °C, white (oac909) to grey (oac851). Conidiogenous cells arising from hyphae laterally or terminally, hyaline, tapering gradually or abruptly into a long slender neck. Conidia hyaline, septate (1–4), arising from phialides at the apex of each neck, fusiform, (7–)9–15.5(–20) × (2–)2.5–4 µm.
Colonies on SDYA/4, attaining a diam. of 19 mm within 20 d at 25 °C, cream (oac816) to brown (oac781). Conidiogenous cells arising from hyphae laterally or terminally, hyaline, tapering gradually or abruptly into a long slender neck. Conidia hyaline, septate, arising from phialides at the apex of each neck, fusiform, (7–)9–18.5(–27) × (3–)3.5–6(–8) µm.
Only reported from Khao Yai National Park.
Parasitic on a pair of termites from a reproductive caste (Order Isoptera: Family Termitidae, Subfamily Macrotermitinae) and these specimens were buried in the soil. The fungus emerged from the segment between the prothorax and mesothorax of one of the termite pairs.
THAILAND. Khonkaen Province, Phu Wiang National Park; 16°799'N, 102°279'E; on termite; 17 July 2017; K. Tasanathai, S. Mongkolsamrit, W. Noisripoom (holotype BBH45361 dried culture; ex-type living culture, BCC86431). GenBank: ITS = MH754721, LSU = MH753674, TEF = MK284262, RPB1 = MK751469, RPB2 = MK214090
Ophiocordyceps pseudorhizoidea (BBH45361, BCC86431) A stroma of fungus emerging from termite B part of stroma showing perithecia C perithecia D, E ascus F ascospore G, H phialides with conidia from synnema I colony on PDA at 20 d obverse and reverse J, K, L phialides with conidia on PDA M, N, O conidium P colony on PSA at 20 d obverse and reverse Q, R, S phialides with conidia on PSA T, U conidia with mucous sheath. Scale bars: 15 mm (A); 1 mm (B); 120 μm (C); 8 μm (D, E); 10 μm (F, G); 3 μm (H, R); 6 mm (I, P); 5 μm (J, K, L, Q); 2 μm (M, N, O, T, U); 4 μm (S).
‘pseudorhizoidea’ referring to close affinity to what was called Ophiocordyceps rhizoidea on termites by NHJ.
Stroma solitary, simple, filiform, up to 21 cm long, 1 mm wide, light-brown (oac675), ca. 15 cm emerging above leaf litter, 5.5 cm buried in the soil. Asexual state (Hirsutella) produced at the terminal part of the stroma, ca. 6 cm long, light brown to grey. Perithecia superficial, ovoid, covering the middle part of stroma, (280–) 287.5–315.5 (–390) × (160–) 177–209.5 (–220) µm. Asci 8-spored, cylindrical, 120–150 × 5–7 µm with cap, 3–4 × 4–5 µm. Ascospores whole, filiform, (65–) 69.5–78.5 (–82.5) × 2–2.8 (–3) µm, with septate. Asexual state Hirsutella. Phialides (10–)15.5–23.5(–26) × 3–4(–5) µm, conidia hyaline, fusiform, (5–)5.5–6.5(–7) × 3–4 µm.
Colonies on PDA, attaining a diam. of 10 mm within 20 d at 25 °C, cream to grey (oac844), reverse oac772 to oac815. Conidiogenous cells monophialidic, arising from hyphae laterally or terminally, hyaline, tapering gradually or abruptly into a long slender neck, (9–)10.5–17.5(–21) µm long, 2–3.2(–4) µm wide at the base, 1–1.5 µm wide at tip with warty surface. Conidia hyaline, one-celled, fusiform, (5–)6.5–8.5(–10) × 1–2 µm. with mucous sheath.
Colonies on PSA, attaining a diam. of 10 mm within 20 d at 25 °C, (oac841) to (oac843), reverse (oac868). Conidiogenous cells monophialidic cells arising from hyphae laterally or terminally, hyaline, tapering gradually or abruptly into a long slender neck, (10–)12–16.5(–19) µm long, 2–3 µm wide at the base, 1–1.5 µm wide at tip with warty surface. Conidia hyaline, one-celled, arising from phialides, fusiform, (6–)6.5–8(–8.5) × 1.5–2.5(–3) µm with mucous sheath.
Colonies on SDYA/4, attaining a diam. of 10 mm within 20 d at 25 °C, oac844, reverse oac722 in middle to oac815. Conidiogenous cells monophialidic cells arising from hyphae laterally or terminally, hyaline, tapering gradually or abruptly into a long slender neck, (13–)17–25.5(–30) µm long, (3–)3.5–4 µm wide at the base, 1 µm wide at tip with warty surface. Conidia hyaline, one-celled, arising from phialides, fusiform, (6–)7.5–9(–10) × 1–2 µm with mucous sheath.
Thailand.
Parasitic on a pair of termites from a reproductive caste (Order Isoptera: Family Termitidae, Subfamily Macrotermitinae) and these specimens were buried in the soil. The fungus emerged from the segment between the prothorax and mesothorax of one of the termite pairs.
THAILAND. Chanthaburi Province, Khao Soi Dao Wildlife Sanctuary; 13°136'N, 102°218'E; on termite; 8 June 2011; K. Tasanathai, P. Srikitikulchai, S. Mongkolsamrit, A. Khonsanit, K. Sansatchanon (BBH31259, BCC 48879).
Like O. communis and O. pseudocommunis, this species shows similarity to O. rhizoidea. However, von Hohnel’s description of the host in O. rhizoidea was a Coleoptera larva. O. rhizoidea has longer and wider asci and ascospores than O. pseudorhizoidea, while in O. communis and O. pseudocommunis, they are distinctly longer (Table
Morphological comparisons of closely related Ophiocordyceps species used in this study
Species | Host | Stromata (cm) | Perithecia (µm) | Asci (µm) | Ascospores (µm) | Reference |
---|---|---|---|---|---|---|
Ophiocordyceps asiatica | Termites | solitary, simple, filiform, up to 15 long orange brown | superficial, globose to subglobose 240–320 × 180–260 | filiform 92.5–175 × 5–6.3 | whole with septate 90–132.5 × 1–2 | This study |
Ophiocordyceps brunneirubra | Termites | solitary, simple or branched, narrowly clavate, slender and wiry, 9.5 cm long, orange brown to red brown | Immersed, ovoid, 300–400 × 130–200 | cylindrical, 155–225 × 4.5–8 | filiform, whole with septate, 156.5–197.5 × 2–3 | This study |
Ophiocordyceps khokpasiensis | Termites | solitary, simple cylindrical, 16 cm long, brown | pseudo-immersed, subglobose 200–250 × 120–200 | filiform, 62.5–125 × 4–5 | filiform, whole, 46–90 × 2–3 | This study |
Ophiocordyceps mosingtoensis | Termites | solitary simple cylindrical, 11 cm long, brown to grey | pseudo-immersed, ovoid 400–500 × 200–300 | filiform, 187.5–287.5 × 4.5–7.5 | whole with septate, 230–315 × 1.5–3 | This study |
Ophiocordyceps pseudocommunis | Termites | solitary simple cylindrical , 21 cm long, brown | superficial, subglobose 520–600 × 360–440 | filiform, 160–165 × 14–17 | whole with 7–8 septa, 107.5–147.5 × 6–7.5 | This study |
Ophiocordyceps communis | Termites | solitary simple filiform, 5-13 cm long, yellow brown | superficial 285-675 × 195-390 | filiform, 215-250 × 15 | filiform, whole, 100–180 × 5–6 |
|
Ophiocordyceps pseudorhizoidea | Termites | solitary, simple, filiform, up to 21 cm long, light brown | superficial, ovoid 280–390 × 160–220 | cylindrical, 120–150 × 5–7 | whole with septate 65–82.5 × 2–3 | This study |
Ophiocordyceps rhizoidea | Coleoptera larva | simple, solitary, 7–8 cm long, 0.5-1 mm | superficial 360 × 300 | 160-210 × 13-16 | ca 80 × 5-7 | von Höhnel, 1909 |
Ophiocordyceps termiticola | Termites | solitary, simple, filiform, up to 14 cm long yellow brown | pseudo-immersed, globose to subglobose 200–280 × 150–250 | filiform 62.5–110 × 4–6 | filiform, whole, 85 × 2 | This study |
THAILAND. Kanchanaburi Province, Khao Laem National Park; 14°746'N, 98°625'E; on termite; 20 June 1995; N.L. Hywel-Jones, R. Nasit, S. Sivichai (holotype BBH5634 dried culture; ex-type living culture, BCC 1920). GenBank: ITS = MH754724, LSU = MH753678, TEF = MK284265, RPB1 = MK214108, RPB2 = MK214094
Ophiocordyceps termiticola (BBH5634, BCC 1920) A stroma of fungus emerging from termite B part of stroma showing perithecia C perithecia D ascus E ascospore F phialides with conidia on synnema G conidium H colony on PDA at 20 d obverse and reverse I phialides with conidia on PDA J conidium K–O scanning electron micrographs of phialides with conidia on PDA P colony on PSA at 20 d obverse and reverse Q phialides with conidia on PSA R colony on SDYA/4 at 20 d obverse and reverse S phialides with conidia. Scale bars: 2 cm (A); 1 μm (B, K, O); 100 μm (C); 15 μm (D); 8 μm (E); 5 μm (F, G); 7 mm (H, P, R); 3 μm (I, J, L, M, N, Q, S).
‘termiticola’ referring to the host family, Termitidae.
Stroma solitary, simple, filiform, up to 14 cm long, 1 mm wide, yellow-brown, ca. 6 cm emerging above the leaf litter, ca. 8 cm buried in the soil. Asexual state (Hymenostilbe-like) produced ca. 1 cm at the terminal part of the stroma, grey. Perithecia pseudo-immersed, globose to subglobose, produced on one-third of the terminal part of the stroma ending near the apex, (200–)225–261(–280) × (150–)178–229(–250) µm. Asci 8-spored, filiform, (62.5–)76.5–100.5(–110) × (4–)4.5–5.5(–6) µm. Ascospores whole, filiform, 85 × 2 µm, Asexual state Hymenostilbe-like, conidiogenous cells formed a compact hymenium-like layer and had from two to four denticles at their apices, cylindrical to clavate, (10–)11.5–16(–17) × 3–5(–6) µm. Conidia, hyaline, fusiform 7 × 3 µm.
Colonies on PDA, attaining a diam. of 28 mm within 20 d at 25 °C, grey (oac781) to pale grey (oac851). Conidiogenous cells monophialidic to polyphialidic, arising from hyphae laterally, with an inflated base (7–)7.5–10(–11) × (2.5–) 3–3.5(–4) µm. Conidia hyaline, globose, 2.5–3 (–3.5) µm, one-celled with warty surface.
Colonies on PSA, attaining a diam. of 22 mm within 20 d at 25 °C, white to pale grey, cotton-like. Conidiogenous cells monophialidic to polyphialidic, hyaline, smooth, with an inflated base (7–)8–10.5(–13) × 3–4 (–5) µm. Conidia hyaline, globose, (2–)2.7–3.4(–4) µm, one celled with warty surface.
Colonies on SDYA/4, attaining a diam. of 29 mm within 20 d at 25 °C, grey to pale grey (oac851). Conidiogenous cells monophialidic to polyphialidic, hyaline, smooth, with an inflated base (7–)8–10.5(–13) × 3–4 µm. Conidia hyaline, globose, 3–3.5(–4) µm, one-celled with warty surface.
Thailand.
Parasitic on a pair of termites from a reproductive caste (Order Isoptera: Family Termitidae, Subfamily Macrotermitinae) and these specimens were buried in the soil. The fungus emerged from the segment between the prothorax and mesothorax of one of the termite pairs.
THAILAND. Chanthaburi Province, Khao Soi Dao Wildlife Reserve; 13°136'N, 102°218'E; on termite; 20 June 1996; R. Nasit, S. Sivichai, K. Tasanathai (BBH5179, BCC1770).
Both O. termiticola and O. khokpasiensis produce pseudo-immersed reddish perithecia on a stroma. In O. termiticola, the perithecia are tightly packed, while in O. khokpasiensis, they are loosely aggregated and the length of the anamorphic layer at the end of the fertile part is longer in the latter.
Out of the 230+ species of Ophiocordyceps worldwide, less than 10 species occur on termites. The majority of these species produce cylindrical, wiry to pliant, mostly simple, seldom multiple, stromata. Species found in Africa and Mexico, O. bispora (Cordycepioideus bisporus) and O. octospora (Cordycepioideus octosporus), produce thick-walled, multiseptate ascospores, suggesting an adaptation to the harsh environmental conditions in these countries (
Interestingly, our results clearly present Ophiocordyceps species occurring on reproductive castes of termites, especially subterranean termite species in the Family Termitidae, Subfamily Macrotermitinae. All species of subterranean termites construct their nests below ground or build mounds above ground and excavate their foraging tunnel in several ways (
Fungi represent a silent threat to the termite community. Termites have many predators, such as other amphibians (toads), birds, reptiles (lizards, gecko, snakes), small mammals, rodents and even humans. The percentage of the infection to these reproductive castes may be low in comparison to the individuals in a termite swarm, however, only few survive or evade the imminent threat of arthropods and other animals. Eventually, the number of infections caused by Ophiocordyceps becomes significant when only a few can actually survive to start a new colony.
The number of available morphological characters needed to delimit species in fungi are so limited and this may be an important reason why cryptic species are abundant in Kingdom Fungi, i.e. morphologically indistinguishable biological/phylogenetic units present within taxonomic species (
The knowledge that Ophiocordyceps species infect reproductive castes of termites can be used as basic information to study the biological control of subterranean termite pests and to better implement them. All specimens of termites collected are subterranean termites and produce relatively fast growing synnemata with numerous infectious propagules (ascopores) which can be developed further for biological control strategies.
The authors are grateful to Platform Technology Management Section, National Center for Genetic Engineering and Biotechnology (BIOTEC), Grant No. P19-50231 and CPMO Grant No. P15-51452 for their support of the biodiversity studies of invertebrate-pathogenic fungi in Thailand. We thank the Department of National Parks for their kind support and permission to collect fungi in the national parks. We also thank Suchada Mongkolsamrit for her help in collecting fungi. This study was supported by National Science and Technology Development Agency (NSTDA). We are grateful to the reviewers whose comments and suggestions helped improve our manuscript.