Colonization of greenhouse nematode cultures by nematophagous mites and fungi

Abstract

Unproductive > 7-year-old greenhouse cultures of citrus nematode (Tylenchulus semipenetrans) had a well-developed soil invertebrate fauna that included nematophagous mite species characteristic of Florida citrus groves. Nematophagous mite densities in box cultures were 285 +/- 42 mites/liter, 2.5 to 25 times higher than densities in citrus nematode-infested groves. Vigorous root-knot nematode (Meloidogyne incognita) cultures grown in steam-pasteurized soil had few nematophagous mites until more than 3 months after inoculation. Mite species diversity had a significant (P < 0.0001) positive linear relationship with culture age that explained about one-half the variance in species number. Nematophagous mite densities rose and then fell with culture age. In root-knot cultures > 3-months-old, mite densities often exceeded 1,000 mites/liter. Twelve species of nematophagous fungi also were isolated from greenhouse nematode cultures.

Keywords: Meloidogyne incognita; Tylenchulus semipenetrans; biological control; culture; fungus; mite; nematode; nematophagous fungus.