KEY to Commonly Occurring Nematophagous Fungi in Hawaii and Florida
Koon-Hui Wang, Robert McSorley
PREFACE: This key for nematophagous fungi is simplified from the key of Cooke and Godfreys (1963) with the focus on nematode-trapping fungi and endoparasitic fungi. Nematophagous fungi that have been reported in Hawaii or Florida are highlighted in blue. Many of the pictures attached are from the collection and publications from Dr. R. Esser, Society of Nematologists biocontrol slide set, as well as the authors’ collection. The authors recommend readers to use the original key for species identification and only use this key as a pictorial guidance.
KEY TO NEMATOPHAGOUS FUNGI
1. Endoparasitic fungi (mycelium in the life cycle predominantly inside nematode host) 2
1. Predatory fungi (mycelium in the life cycle predominantly outside nematode host) 13
2. Assimilative hyphae within host transformed into fertile hyphae, extended out of host slightly, producing adhesive cells or ingestive conidia 3
2. Vegetative hyphae within host transformed into sporangia producing zoospores, or producing conidia, zygospores or azygospores
9
Endoparasitic Fungi with Adhesive Cells or Ingestive Spores
3. Hyphae aseptate
3. Hyphae septate 4
4. Hyphae with clamp connection 5
4. Hyphae without clamp connection 7
(Nematoctonus)
5. Hyphae bearing adhesive cells (knobs)
a. Nematoctonus robustus Jones
b. N. concurrens Drechs.
c. N. haptocladus Drechs.
d. N. campylosporus Drechs.
5. Hyphae lacking adhesive cells, but producing adhesive knobs on conidium 6
6. Chlamydospores produced
a. Nematoctonus pachysporus Drechs.
b. N. tylosporus Drechs.
6. Chlamydospores not produced
a. Nematoctonus leiosporus Drechs.
b. N. leptosporus Drechs.
7. Conidia borne on strigmata, no phialides
a. Meria coniospora Drechs.
7. Conidia borne on phialide 8
8. Conidia adhesive
a. Hirsutella rhossiliensis
8. Conidia filiform
a. Harposporium helicoids Drechs.
b. H. oxycoracum Drechs.
c. H. subuliforme Drechs.
8. Conidia arcuate
a. H. anguillulae Lohde (Karling)
b. H. liliputanum Dixon
c. H. crassum Shepard
8. Conidia straight or slightly curved
a. H. baculiforme Drechs.
b. H. sicyodes Drechs.
8. Conidia pea-pod, barbed at one or both ends
a. H. bysmatosporum Drechs.
b. H. diceraeum Drechs.
(See Species of Harposporium spp.in Esser, 1992)
9. Vegetative hyphae within the host developed into conidiophores that pass out of host, producing conidia.
a. Meristracum asterospermum Drechs.
Endoparasites that Produce Encysting Spores
9. Vegetative hyphae within the host transformed into sporangia producing spores 10
(See Fungi that utilize zoospores to parasitize nematodes by Esser and Schubert, 1983)
10. Sporangium (zoosporangium) producing motile zoospores 11
10. Sporagium producing inmotile spores 12
11. Zoospores uniflagellate, no zygospores, no resting spores.
a. Catenaria anguillulae Sorokin
(see Pathogenicity of selected nematodes by Catenaria anguillulae, Esser and Ridings, 1973)
b. Rhizophydium sp.
11. Zoospores biflagellate, may form zygospres, produce resting spores.
a. Lagenidium caudatum Barron
b. Myzocythium vermicola (Zopf) Fischer
c. M. glutinosporum Barron
d. M. humicola Barron & Percy
e. Nematophthora gynophila Kerry & Crump
12. Spores globular or polyhedral with a lobed appendages.
a. Haptoglossa heterospora Drechs.
12. Spores clavate.
a. Protascus subuliformis Dangeard
Nematode-Trapping Fungi
13. Morphologically unmodified hyphae 14
13. Morphologically modified hyphae forming traps 17
14. Hyphae aseptate with yellow adhesive substances at contact 15
14. Hyphae septate 16
Adhesive Mycelia
15. Produce conidia on simple conidiophore.
a. Stylopage hadra Drechs.
b. S. leiohypha Drechs.
c. S. grandis Drechs.
15. Without conidia, but chlamydospores formed.
a. Chlamydospores formed laterally: Cystopage lateralis Drechs.
b. Chlamydospores formed intercalary: C. intercalaris Drechs.
c. Chlamydospores on crooked branches or intercalary: C. cladospora Drechs.
16. Conidia bifurcate
a. Triposporina aphanopaga Drechs.
16. Conidia furcated, trident-like.
a. Tridentaria implicans Drechs.
17. Hyphae aseptate, lateral branches bearing poorly differentiated adhesive knobs.
a. Acaulopage pectospora Drechs.
17. Hyphae septate 18
18. Hyphae forming adhesive branches, sometimes forming simple 2-dimensional network; conidiophore simple, single terminal conidium.
Adhesive Branches
(see Fungi employing mucilaginous hyphal, sessile, or stalked globose cells to entrap nematodes by Esser and Schubert, 1982).
a. Monacrosporium cionopagum (Drechs) Subram.
b. Dactylella gephyropaga Drechs.
c. Dactylella lobata Duddington
18. Hyphae forming stalked or sessile adhesive knobs 19
18. Hyphae forming stalked non-constricting rings, sometimes accompanied by stalked adhesive knobs 21
18. Hyphae forming stalked constricting rings 22
18. Hyphae anastomosing to form 2 or 3 dimensional adhesive networks 23
Adhesive Knobs
19. Conidiophore branched
a. Dactylaria haptospora Drechs.
b. D. haptotyla Drechs.
c. D. sclerohypha Drechs.
19. Conidiophore simple 20
20. Adhesive knobs always sessile
a. Monacrosporium phymatopagum (Drechs.) Subram.
20. Adhesive knobs sessile or short-stalked, often forming short chains of adhesive cells.
a. M. parvicollis (Drechs.) Cooke & Dickinson
20. Adhesive knobs always stalked, simple conidiophore.
a. M. ellipsosporum (Grove) Cooke & Dickinson
b. M. mammilatum (Dixon) Cooke & Dickinson
20. Adhesive knobs always stalked, conidiophore branched.
a. Dactylella asthenopaga Drechs.
Non-constricting Rings
21. Adhesive knobs not present.
a. Dactylella leptospora Drechs.
21. Adhesive knobs present, conidiophore simple.
a. Monacrosporium lysipagum (Drechs.) Subram.
21. Adhesive knobs present, conidiospore branched.
a. Dactylaria candida (Nees) Sacc. Drechs.
Constricting Rings
(See Fungi that entrap and assimilate nematodes by employing constricting rings by Esser and Schubert, 1991)
22. Conidia borne in a terminal cluster on conidiophore.
a. Arthrobotrys anchonia Drechs.
b. A. dactyloides Drechs.
c. A. brochopaga (Drechs.) Schenk, Kendrick, & Pramer
d. A. gracilis (Dudd.) Schenk, Kendrick, & Pramer
22. Conidium borne singly on a simple conidiophore.
a. Trichothecium polybrochum Drechs.
b. Monacrosporium acrochaetum (Drechs.) Cooke
c. M. doedycoides (Drechs.) Cooke & Dickinson
e. M. stenobrochaum (Drech.) Subram.
f. M. bembicodes (Drech.) Subram
g. M. turkmenicum (Sopronov) Cooke & Dickinson
h. M. coelobrochum (Drechs) Subram.
i. M. acrochaetum (Drechs.) Subram.
3-dimensional Networks
23. Conidia with one septum
a. Trichothecium cystoporium Dudd.
b. T. flagrans Dudd.
c. T. pravicovi Soprunov
d. T. globosporum var globosporum Soprunov
e. T. globosporum var microsporum Soprunov
f. T. globosporum var roseum Soprunov
g. Arthrobotrys arthrobotryoides (Berl.) Lindau Drechs.
h. A. conoides Drechs.
i. A. oligospora Fresenius
j. A. superba (Corda) Drechs.
k. A. longispora Soprunov
l. A. oviformis Soprunov
m. A. doliformis Soprunov
n. A. kirghizica Soprunov
o. A. cladodes var cladodes Drechs.
p. A. cladodes var macroides Drechs.
q. A. robusta Dudd.
r. A. musiformis Drechs.
23. Conidia with more than one septum.
a. Dactylaria eudermata Drechs.
b. D. psychrophila Drechs.
c. D. megalospora Drechs.
d. D. reticulata Drechs.
e. D. thaumasia Drechs.
f. D. polycephala Drechs.
g. D. pyriformis Juniper
h. D. scaphoides Peach
i. D. gampsospora Drechs.
Reference
Cooke, R. C. and B. E. S. Godfrey. 1964. A key to the nematode-destroying fungi. Trans. Brit. Mycol. Soc. 47: 61-74.
Poster
Ching, S., Loffredo, A. and K.-H. Wang. 2013. Enhancing nematode-trapping fungi in the soil using a no-till mix cover cropping system. CTAHR Student Research Symposium, Honolulu, Hawaii (Abstract #9).