Within the framework of the project some important insights could be gained, which can serve as a basis for future projects.

The difficult task to mate the yellow-legged clearwing under artificial conditions could be solved within the framework of this project.

Within the framework of the project some important insights could be gained, which can serve as a basis for future projects.

The difficult task to mate the yellow-legged clearwing under artificial conditions could be solved within the framework of this project. Important insights on the development of mass breeding, e.g. on the recipe of a culture medium, and on the conditions, under which caterpillars should be kept, could be worked out as a basis for further projects. It has turned out that cool-wet weather conditions constitute for both indigenous varieties of clearwings a great risk in the infestive stage, thus in the period between the emergence of the larva from the egg and the nidation of the larva in the root. Moreover, the results indicate that the caterpillars of the clearwings can and/or must move a few centimetres deep into the soil in order to find an appropriate place to penetrate into the root. Both insights are of great importance for the development of a practical and efficient inoculation method. In cooperation between the members of the Operational Group, the prototype of a capsule has been developed which is to enable an inoculation of sorrel plants with larvae of clearwings, which is as independent from the weather and as practical as possible. This prototype can also serve as a basis for further projects on this topic.

The pilot project has shown very clearly that for the development and the implementation of an organic sorrel control by means of the clearwing fundamental insights on these animals will still have to be gained. These insights are necessary in order to be able to practice a stable mass breeding and to develop an efficient inoculation method, which is independent from the weather.  The Operational Group “Organic Sorrel Control” has therefore come to the conclusion that the project should be terminated prematurely. First of all research work to gain fundamental knowledge has to be carried out. Only then the work on the development and the implementation of the use of clearwings in practice can be started again. As soon as an efficient inoculation method, which is independent from the weather conditions, is available and breeding of clearwings enables a stable egg production, the actual potential of sorrel control of the clearwing for Austrian grassland farming, thus the ability to reduce sorrel stands, can be tested in practical experiments.   

The fundamental goal of the pilot project was to answer the question whether the use of the indigenous clearwing (Pyropteron chrysidiformis) for the purpose of organic sorrel control is sufficiently efficient, practicable, and feasible for Austrian grassland farming.  The larvae of the clearwing eat the roots of the sorrel plants and hit them thus at a decisive spot (see “strategy on organic sorrel control” at http://arge-ampfer.at/strategie-zur-biologischen-ampferbekaempfung/). For the project larvae of the clearwing were collected from natural populations and further raised in the laboratory for egg production. The eggs produced were spread on areas for practical experimentation for the purpose of collecting information on the eating efficiency. In order to inoculate the sorrel plants with the caterpillars of the clearwing the “egg stick method” was selected. According to literature, this method works best. For this purpose, the eggs were glued on wood sticks, which were subsequently inserted into the sprout of the sorrel plant. On the basis of the project results the Operational Group “organic sorrel control” came to the assessment that the “organic sorrel control by means of the clearwing” constitutes, at the present state of affairs, no efficient, practical option of control for Austrian grassland farming. The inoculation method with egg sticks has resulted, under practical conditions, only in a very weak infection quota. The potential of the clearwing for the purpose of sorrel control can be continued to be estimated as high, provided that an efficient, practical inoculation method, which will work regardless of the weather, can be developed. 

The expected outcome of the Operational Group “Organic dock control” is a strategy for organic dock control which is developed in close cooperation of the individual stakeholders from practice, advisory services and research and which can be used as a basis of decision-making in the development of further products.