Ecological characteristics of nematode ‐trapping Hyphomycetes

Abstract

SUMMARY A study of thirteen species of nematode‐trapping Hyphomycetes demonstrated wide differences in their growth rate, competitive saprophytic ability, effect on free‐living nematode populations and ability to produce traps spontaneously. The species producing adhesive reticulate traps tended to have the most rapid growth rates and the highest saprophytic ability ratings. In the soil they appeared to be pre‐daceously inefficient and did not form traps in pure culture. In contrast the ring‐formers had slow growth rates and lower saprophytic ability ratings. They tended to be predaceously efficient and two of the four species studied formed traps spontaneously. The adhesive branch or knob‐forming fungi resembled the ring‐formers in their growth rates, predaceous efficiency and spontaneous trap formation. Thus it appears that the development of predaceous efficiency has been accompanied by a tendency to lose those characters associated with an efficient saprophytic existence in the soil; namely rapid growth rate and good competitive saprophytic ability.