In order to make use of B. penetrans the preparation of these bacteria was prepared successfully. Each gram of the specimen contains more than 3.1×10 8 spores according to determination by bloodcount plate. The method of its production are: First, infect the larvae of root-knot nematodes with the spores of B. penetrans. Second, inoculate infectable plants with the infected larvae. Third, beat the root-systems of inoculated plants after adding some water. The flowed liquid from a bronze sieve was mixed with the clear water, filtered, precipitated, air-dried under 5～10℃, and grinded into fine powder, When these powder was added into the water which contained the larvae of root-knot nematodes, the spores of B. penetrans adhered to the cuticles of these larvae in 24h. The pot experiments of tomato, chilli and cockscomb showed that the galls, egg-sacs, females, males and all-stages of larvae produced by the plant inoculated with the larvae infected with B. penetrans are about 75%～80% less than that without these bacteria. Thus it can be seen that the spores of B. penetrans can depress the populations of root-knot nematodes obviously. Therefore, it is a promising preparation for biological control.

研究了茶苗南方根结线虫（Meloidogyne incognita）虫口密度的季节消长规律和在不同深度根系中的分布，以及茶圃杂草作为其保虫寄主的感染情况。感染率10～12月最高，8月最低，平均感染强度10月最高，7月最低；从上到下在第10～15cm处雌虫最多，第20～25cm侵袭期幼虫晟多；10种杂草感染该虫种。虫口密度随月积温的上升而上升，而雄性比则随月总雨量的升高而下降。

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.

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%。

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。