Entomology - Insect breeding and genetics - An example from practice

  • Entomology, translated as science of insects, is divided into two areas. General entomological research deals with the classification of insect groups. Thus, coleopterologists study beetles and orthopterologists study grasshoppers. The second area is the applied entomological research. It has become very economically relevant as a field of research nowadays. The studies often concentrate on issues from the agricultural industry and the optimization of goods production, being insects for consumption by living creatures or, as described in this article, a study of the University of Zurich that is unique in the world. It examines how quickly an insect species is able to adapt to changing environmental conditions. Compared to the past, research today is under high pressure. It usually has to be economically profitable. On the one hand, fast and comprehensive results are needed, and on the other hand, great flexibility is required to carry out the experiments. The studies require equipment that is able to accurately simulate conditions over years. Clitec is the preferred supplier for this kind of equipment because the environmental conditions can be precisely simulated and reproduced.

    Process of the studies IN the example of the University of Zurich

    Researchers at the University of Zurich are successfully using climate chambers from Clitec for entomological research. In long-term experiments, they are investigating how herbivorous insects, such as the cabbage moth (diamondback moth, Plutella xylostella), adapt to natural defenses in a plant. The cabbage moth is a notorious pest that mostly eats cabbage plants (Brassicaceae). Schoterich (wallflower, Erysimum cheiranthoides), on the other hand, is largely protected from feeding by a newly developed plant toxin. Even though the cabbage moth occasionally feeds on the schoterich, it has not yet developed a natural resistance to the novel plant toxin.

    Clitec Technical Report Entomology 2

    Researchers at the University of Zurich are specifically using artificial selection to increase the resistance of the cabbage moth to the plant toxin of the schoterich. In real time, the researchers are tracking this buildup of resistance to better predict future changes in the cabbage moth’s natural population from the findings. Under the constant climatic conditions in the climate chambers of Clitec, cabbage moth caterpillars are fed either on schoterich or broccoli. Broccoli (Brassica oleracea italica) serves as a reference. The surviving caterpillars develop into moths, which mate and lay the next generation as eggs. With each generation that develops on schoterich plants, individual insects that are particularly good at handling the novel toxins are sorted out. At regular intervals, the researchers investigate the feeding behavior of the selected cabbage moths and finally compare gene sequences between cabbage moths that have evolved over generations on schoterich or broccoli. The growth and the health of the cabbage moth are highly dependent on temperature, humidity and plant quality. Only with accurate and constant regulation of climatic conditions, over several years, it is possible to clearly demonstrate the initially small effects of progressive adaptation. The study is, to remark on, unique worldwide and requires therefore a highly systematic approach. This also places the highest demands on reproducible test conditions, which can only be achieved with high-quality climate chambers. The climatic chambers of Clitec make this conditions possible.

    Technical requirements

    A normal refrigerator or heating cabinet does not meet the high requirements of reproducible experimental conditions. Therefore Clitec offers high-end climate chambers which guarantee exactly this reproducibility and cover the specific requirements of insect breeding:

    • In the experiments, the first thing to do is to optimize the temperature and humidity. Plants as well as insects should feel comfortable. The specific conditions, despite short or even longer test time, should be reproducible. Temperature determines the growth of insects. Watering determines the moisture of the plants and thus how quickly the leaves dry out or whether diseases emerge.
    • Plants absolutely need light for photosynthesis. The reaction of the insects to the type of light is interesting. Cabbage moths do not react to flickering light, whereas bumblebees (Bombus) loose their orientation. Other insect groups respond to UV-light. Thus, the right light must also be used to make the experiments successful and reproducible.
    • A net is necessary to keep the insects in the cage, but hinders the airflow and so, especially with small mesh sizes of the nets, a mostly undesirable microclimate is formed. Relief is possible by higher air circulation or additional fans that suck the air out of the cages.
    • To minimize the space required, the cages should be adapted to the growth height of the plants and the size of the cabinet. The lighting is preferably mounted on the side.
    • Special in insect breeding is the coating with phenols. The reason: insect excretions attack metals with low chemical resistance. Coating of copper or aluminum pipes in the heat exchanger prevents this and thus ensures the reliable operation of climatic chambers for years.

    Choose the right equipment

    The climate chambers from Clitec, especially for insect breeding, offer maximum usability in a compact space. Wheter cabinets on wheels with allow flexible choice of location for a laboratory or permanently installed walk-in rooms for a production facility – there are different designs available. Clitec is the contact for optimized climate chambers for research purposes and industry. Standard chambers in different sizes or customized climatic chambers are available from first-class manufacturers. You design the climate rooms according to your needs, from the layout of the interior with shelves and inserts, to the cooling system and lighting, to the ventilation and humidification systems.

    Clitec distinguishes by the customers in insect breeding and the experience with various applications. A personal consultation on the technical design of the equipment to be purchased or on the suitable interior installations can help to perfectly match the equipment to your application.