A study was made of the temporal fluctuation in the population density of Meloidogynefujianensis parasitizing the roots of Citrus reticulata growing in Nanjing County, China. The lowest infection rate occurred in August (30%), and the highest in April of the following year (90%). The lowest average infectivity was re-corded in August (1.8 females/2g roots) and the highest in February of the following year (24.2 females/plant). Infection occurred throughout the year with peaks of infection in September and October and again in March to April of the following year. The peak of oviposition occurred during December and January. The population density increased with increasing monthly average temperatures. The most active growth of C. reticulata roots coincided with the peaks of infection of nematode juveniles (September-October, March-April), which was as-sociated with two main periods of disease symptomatology. The ratio of males decreased with increasing monthly rainfall.

The paper reports an obligate parasite of some plant-parasitic nematodes-Bacillus penetrans, which was found to be new to China. The optical microphotographes and scan-ning electronic microphotographes of the spores of this kind of bacteria were taken, and the symptom of the infected larvae and females of rootknot nematodes were also described. The infection rates of B. penetrans in a number of plants in Xiamen were investigated and the tests of inoculation of the spores were conducted. The results indicate that Pratylenchus sp. and the larvae of N. incognita, M. javanica, M. arenaria, M. hapla and M. fujianensis are easily infected with spores of B. penetrans, and the latter has been found to be new record of the host-nematode of this kind of.bacteria, while the larvae of Heterodera cacti and Rotylenchulus reniformis are not be infected. The infected larvae decrease their activity and even will die. The bodies of the infected females are full of spores and can not produce egg. Therefore, it is hopeful that B. penetrans will get plant nematodes under control. Among 3 species of root-knot nematodes parasitizing 16 species of host plants investi-gated, only the females of both M. incognita parasitizing Hibiscus schizopetalus, Solanum nigrum, and S. melongena and M. javanica parasitizing Achyranthes aspera have the spores of this kind of bacteria. There are only few B. penetrans in the nature according as they have been searched out only in 4.9% of 1529 females of all plants investigated (1.8% of 390 females of crops). Therefore, the authors think that the biological control of root-knot nematodes will become practical only after finding a way out of a difficulty of the mass production of the spores of this superparasite.

稻米生产在亚洲国家，特别是在我国具有经济重要性，可是关于水稻线虫的为害研究还比较少，目前已经知道与水稻有关的线虫有32种（Ichinohe，in webster，1972），干尖线虫（Aphelenchoides besseyi）是为害水稻主要的四种线虫之一。本文在调查的基础上研究其胚前发育、胚后发育和移行规律，为大田防治提供生物学依据。

从寄生在番茄的南方根结线虫（Meloidogyne incognita）卵块中分离到一种破坏线虫的内寄生真菌淡紫拟青霉（Paecilomyces lilacinus），并利用啤酒厂的废渣、废液生产出菌剂。该菌剂每克样品含孢子量为3.4×10 6，用其进行防治根结线虫的盆栽试验。每1600ml土壤施8g比施1g菌剂的根结指数、虫瘿、卵块、雌虫和幼虫分别减少65%、94.0%、94.0%、95.95和97.9%。

作者于1982年在厦门仙人掌[Opuntia dillenii （Ker） How]的根部发现一种形成胞囊的线虫，鉴定为仙人掌仙人掌皮线虫（Cactodera cacti），并对其胞囊、幼虫和卵进行了扫描电镜观察。扫描电镜下的主要特征是：胞囊突出的阴门锥背侧有一凹陷区，为雌虫的尾端。环膜孔，有阴门小齿。尾端与膜孔之间有2～3条表皮花纹。卵壳内壁密布大小不一的刻点。第二期幼虫头部中央椭圆形的唇盘与周围的6个唇是分开的，而两个侧背唇之间和两个侧腹唇之间也都是分开的，即各不愈合。头区有4条完整的环纹，环纹呈六边形。