TYROPHAGUS PUTRESCENTIAE AND HYPOASPIS CALCUTTAENSIS, ON ROOT-KNOT NEMATODE, MELOIDOGYNE JAVANICA

Abstract

The feeding and predatory behavior of two nematophagous mites viz., Tyrophagus putrescentiae and Hypoaspis calcuttaensis was studied in vitro on Meloidogyne javanica. T. putrescentiae consumed any nematode prey encountered while wandering; it fed on one nematode for sometimes, left it injured and started feeing on the other. H. calcuttaensis actively searched for its prey and predated continuously; it devoured the nematode in toto. The mouth parts are suggestive of this differential feeding behaviour of the two mite species. Both the mite species fed voraciously on the vermiform stages and free eggs of nematodes. Maximum number of nematodes were consumed within the first 24 hrs. T. putrescentiae consumed eggs within eggmasses also, while H. calcuttaensis failed to do so. Both the mite species devoured dead nematodes more efficiently than live ones. All the active developmental stages (larvae, nymphs and adults) of mites were found nematophagous, however, the adults of both the mite species and nymphs of H. calcuttaensis were better predators compared to rest of the developmental stages. Larvae of H. calcuttaensis consumed least number of nematodes. Temperature influenced the rate of predation, maximum predation occurred at 25 ordm;C.