The stages of feeding on larvae of plant parasitic nematodes by soil vampyrellid amoebae were sequentially observed to determine the mechanism of predation. A trophozoite of an isolate identified as Arachnula impatiens captured an active larva of Meloidogyne incognita with fine filopodia, made several holes of 2.5 to 5.5μm in diameter in the wall of cuticular sheath, and completely emptied the contents of the larva within 2 to 3 hr in the aquatic cultures at 25 C. In contrast, another isolate tentatively identified as Vampyrella vorax encysted after surrounding the whole body of larva and 12 to 24 hr were required for completion of feeding. Similar feeding behavior by the two isolates was observed with larvae or adults of Aphelenchoides besseyi and Helicotylenchus dihystera. Jpn. J. Nematol. 14: 1-7 (1984).

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The bodies of M. incognita larvae became shorter with irregularly waving postures after being immersed in 10, 100 and 1, 000ppm solution of aldoxycarb; most intense effect was induced by aldoxycarb at a concentration of 100ppm. Except for those treated with aldoxycarb at a concentration of 1, 000ppm for 5 days, the larvae resumed their motility after being rinsed with distilled water. Numbers and sites of galls induced by these nematodes were investigated on tomato plants which were provided with water and fertilizer through percolation from the bottom of the container. Almost half of the larvae without treatment formed galls on roots extending up to 7.2cm below the surface level. Nematodes rinsed with distilled water before inoculation produced a smaller number of galls on the upper parts of the roots with the increase in the dose of aldoxycarb. When nematodes were inoculated without being rinsed, those suspended in a solution of aldoxycarb (lOppm conc.) produced a few galls within a distance of 1.4cm below the surface level, while the nematodes in solutions with a concentration of 100 and 1, 000ppm did not induce the formation of galls.

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Hoplotylus montanus n. sp., which was collected from rhizosphere of Abies sp. in the subalpine zone of the central Japan, closely resembles H. femina from which it differs in longer body, longer stylet, distinct spermatheca with sperms in female, and clavate tail terminus of male. Pratylenchoides magnicaudoides n. sp. from rhizosphere of Orixa japonica in Shiobara, Tochigi Prefecture differs from the most closely related species, P. magnicauda, in the storter stylet and roundly conical tail terminus in female. Jpn. J. Nematol. 14: 15-19 (1984).

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Thirty-two species of nematodes belonging to 20 genera were detected in mulberry fields and 20 species of 11 genera were found to be parasitic to mulberry. Ogma coffeae, Paratylenchus elachistus, Xiphinema bakeri, Helicotylenchus erythrinae, Meloidogyne mali, Gracilacus yokooi, M. javanica, M. arenaria, H. dihystera and Cryphodera sp. were observed with a high frequency. Nematode fauna of mulberry fields is characterized by a large variety of species including most of the Meloidogyne and Xiphinema species which have been reported in Japan along with the frequent occurrence of G. yokooi and O. coffeae which are seldom observed on other crop plants. On the other hand the occurrence of Pratylenchus, which is often detected in other crops, was unfrequent. M. mali shows a wide geographical distribution in mulberry fields unlike M. hapla and M. incognita. Although the geographical distribution of the nematodes in the fields does not always corespond to the natural distribution dues to the widespread introduction of mulberry saplings infected with nematodes, the following 4 groups can be distinguished: 1. Nematodes observed all over Japan such as P. elachistus, O. coffeae and X. bakeri; 2. Nematodes adapted to low temperature areas including both M. hapla and M. mali; 3. Nematodes occurring in warm areas including Hoplolaimus sp. which is mainly detected in subtropical Okinawa, M. incognita, M. javanica and H. dihystera; and 4. Nematodes adapted to temperature ranges intermediate between those in the cold and warm areas including species such as M. arenaria, Cryphodera sp. and G. yokooi. Both Meloidogyne sp. and Nothocriconemella mutabilis which were only detected in Suginami, Tokyo and Nothocriconema yakushimense in Yakushima Is. do not belong to any of the above 4 groups, suggesting a narrow range of distribution.

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Coslenchus costatus and C. japonicus sp. n. were described and illustrated from Japan. Infra-specific variations of four Japanese populations of C. costatus were discussed comparing with the description of the species by ANDRASSY and showed that there found no differences strict enough to recognize them as being independent from the C. costatus, while a few characters within the description of the species were altered based on the Japanese specimens. C. japonicus sp. n. was related to C. franklinae in having a few head annules, head continuous to body contour, much reduced postuterine sac, however, it was readily distinguished from the latter by having 18 to 21 longitudinal ridges, slightly spaced opening of dorsal oesophageal gland from spear base, generally pre-vulval phasmids, and fewer body annules. Jpn. J. Nematol. 14: 28-39 (1984).

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Growth and propagation of Steinernema feltiae (= Neoaplectana carpocapsae, DD-136) on plain agar, nutrient agar, and 7 kinds of dog food media were investigated at 25t for up to 30 days. On plain agar, the infective juveniles (J_IIIs) did not moult, gradually starved and died. Also the J_IIIs did not moult on the media prepared from ‘soft-type’ dog foods which were shown to contain heat-stable antiseptic substances. On nutrient agar, Ins moulted and developed to adults which produced a few progenies. There progenies which were surrounded by thick colonies of symbiotic bacteria died before maturation. On all kinds of media prepared from ‘dry- type’ dog foods, most of the JIIIs moulted within 5 days after inoculation and developed to parasitic forms. Peak occurrences of adults of the 1st and 2nd generations were recorded 4 and 10 days after the inoculation, respectively. The nematode population rapidly increased from 5 to 15 days after inoculation and then gradually decreased. With the decrease in the population, the percentage of Lis increased and was about 81% 30 days after the inoculation. The nematode population was lower on the media containing smaller amounts of dog food. On the media prepared by mixing softand dry-type dog foods at the rates of 10: 0, 9: 1, 5: 5, 1: 9, and 0: 10, the nematode population rapidly increased on the latter two media, hardly did on the former two, and increased slowly on the others. The role of symbiotic bacteria on the growth and propagation of the nematodes under culture conditions was discussed.

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A root-knot nematode, Meloidogyne suginamiensis n. sp. from mulberry (Morus alba) in Tokyo, Japan, is described and illustrated. This new species differs from M. mali in the female perineal pattern having the slightly squarish outline, wavy striae (oval outline, smooth striae in M. mali); the shorter the more broad tail of the second-stage larvae (24-33, μm vs. 30-34μcm and 30-40μm long of the original description and of the populations of M. mali from mulberry, respectively); and differentiating characteristics of face view of the second-stage larvae as well as of the males in observation by scanning electron microscope. M. suginamiensis n. sp. can also be separated from M. mali in parasitizing on not only woody plants but on various kinds of herbaceous plants. Jpn. J. Nematol. 14: 49-57 (1984).

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