CTAHR logo links to site

University of Hawaii web site College of Trop Agr & Human Resources web site UH at Manoa web site

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.


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


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 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.


Cooke, R. C. and B. E. S. Godfrey. 1964. A key to the nematode-destroying fungi. Trans. Brit. Mycol. Soc. 47: 61-74.


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).

If you require information in an Alternative format, please contact us at: