增殖轮虫养鱼苗的新要点

在池塘中直接增殖轮虫,是解决鱼苗开口饲料、降低生产成本,提高鱼苗成活率和质量的有效途径。现将其技术操作要点介绍如下: 1.排水清塘:轮虫是依靠底泥中的休眠卵重新萌发的。据测定在养鱼的肥水池塘的底泥中。

Test Bench for the Mechanical Distribution of Predators to Control Insect Pests

In agriculture, chemical insecticides are widely used to protect crops from insect pests. Over a period of years, some insects such as Colorado potato beetle （CPB） succeed in developing resistance to most of the registered chemical insecticides. Consequently, heavy applications of chemical insecticides to control this pest become ineffective on a long-term basis and can lead to serious health and environmental problems. The use of natural enemies to control CPB is an interesting alternative to chemical means However, hand release of predators is not feasible on a large scale in the field. The main objective of this research study was to design and build a test bench to investigate the technical feasibility of mechanically releasing predators. The test bench consisted of a vertical chain conveyor mounted on two vertical shafts driven by an electric motor. Since the predators are small and fragile, they were placed in a specially designed container to preserve their physical integrity. Trials using this test bench showed that a carrier material was required, because most of the predators remained inside the container. The success of this mass predator release system will be highly valuable for the biological control of insect pests in many crops.

杂色蛤仔垦区育苗中浮游幼虫与稚贝的培育

福建省在20世纪80年代初期建立了杂色蛤仔(Venerupis variegata)土池育苗的技术工艺，此后，逐步向大面积的垦区育苗发展，并在生产实践巾不断完善育苗工艺，苗种产量亦随之提高。本文根据笔者l998～2002年在福建省福清、平潭两地蛤苗生产中积累的经验，介绍杂色蛤仔垦区育苗中浮游幼虫与稚贝培育各主要环节的技术要点。