A technique for the collection of larvae of Meloidogyne spp. and a comparison of eggs and larvae as inocula.

T h e infectivity of second-stage larvae of Meloidogyne spp. is a function of soil temperature, aeration, moisture, texture, and density, as well as a funct ion of the distance the second-stage larvae have to travel pr ior to root penetra t ion (3, 4). Because eggs may require up to 2 weeks to hatch under greenhouse conditions, infection periods with larvae are normal ly shorter than those with eggs. Larvae inocu lum is easily obta ined by placing galled roots with egg masses in a container over a funnel in a mist chamber. However, a large percentage of larvae become noninfective or they die wi thin 12 to 24 h when numbers accumulat ing in the funnel stem exceed a few thousand. T h e object of this investigation was to compare the yield of larvae of Meloidogyne ineognita (Kofoid and White) Chitwood obtained f rom egg masses in a mist chamber, and that obta ined with a new technique that allows for longer periods of accumulat ion of larvae wi thout loss of infectivity. T h e infectivity of the larvae hatched on the sieve was compared to that of larvae hatched from intact egg masses and from eggs released from egg masses by a sodium hypochlori te (NaOC1) solution (2). Method for collection of infective larvae: Heavi ly galled roots f rom three tomato plants (Lycopersicon esculentum) 'Manapa l ' infected with M. incognita were washed clean of soil, cut in 2to 5-cm segments, mixed, and weighed. Ha l f of the