Observing Trapping

There is a simple way to observe and study insects as they feed on and become trapped in the pitchers. A plant or preferably a single pitcher is covered with a transparent container, such as a wide mouth gallon mayonnaise jar, bell jar, or a plastic bag. A single pitcher is more suitable than a whole plant because if a whole plant is used, a larger container is necessary. Also the insect has more plant area to investigate and, therefore, it may take longer for the insect to settle down and the activity of the insect may be harder to follow. A pitcher should be selected which has a relatively large supply of nectar. The nectar appears on the pitcher as small droplets of liquid which are sticky to the touch. Sarracenia produce the most copious nectar flow in the spring of the year. Often in the fall and winter the pitchers are devoid of nectar.

The pitcher is anchored in a vertical position in a pot of sand or soil and covered with a suitable container. This entire set-up is placed in a sunny area, but not in direct sunlight because the temperature inside may become excessive. (Fig. 3-3)

Now the set-up is ready for insects. We have used houseflies, honeybees, ants, millipedes, centipedes, hornets, grasshoppers, and small beetles. The fastest results are obtained with honeybees, which may be trapped within 10 minutes. The live, captured insect is put in a container which, in turn, is placed in a freezer for 3-5 minutes. This treatment slows the activity of the insect so that it can be handled easily. Care should be taken not to freeze it. The insect is then placed in the container with the pitcher. Within 5-10 minutes after removal from the freezer, the insect is usually active again. If a hole of suitable size is cut through one side of the pitcher near ground level, the trapped insect will have a means of escape. On one occasion we had a honeybee which was trapped and escaped 20 times in one afternoon. There are numerous variations to the set-up. For example, to follow the activities of an insect more easily with species such as S. flava, the hood can be cut off, thus revealing more of the inner surface. In the case of S. minor, a small opening may be cut in the back of the hood, enabling one to follow the activities of the insect inside the hood. Sometimes the insect will fly out of this opening but this may be prevented by taping transparent material over the hole.

Inside Greenhouse Set
Fig. 3-3 Set-up for observing insect capture in Sarracenia.

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