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Malaise Trap


A Malaise trap is a large, tent-like structure used for trapping flying insects, particularly Hymenoptera and Diptera. The trap is made of a material such as terylene netting and can be various colours. Insects fly into the tent wall and are funnelled into a collecting vessel attached to highest point. It was invented by René Malaise in 1934.

There are many versions of the Malaise trap, but the basic structure consists of a tent with a large opening at the bottom for insects to fly into and a tall central wall that directs the flying insects upwards to a cylinder containing a killing agent. The chemicals vary according to purpose and access. Conventionally, cyanide was used inside the jar with an absorbent material. However, due to restrictions, many people use ethanol. Ethanol will damage some flying insects like Lepidopterans, but most people use the Malaise trap primarily for Hymenopterans and Dipterans. In addition, the ethanol will keep the specimens preserved for a longer period of time. Other dry killing agents include no-pest strips (vapona) and ethyl acetate and need to be checked more regularly.

When choosing a Malaise trap design, it is important to consider the types of insects you want to catch. The opening to the cylinder is of key importance. Typically, the opening is around 12–15 mm (0.47–0.59 in), and can vary according to the size of insect you are trying to catch. If using a dry agent, a smaller hole will result in a faster death, limiting the amount of damage a newly caught insect will inflict on older, fragile specimens. In ethanol, this is less of a concern. Larger holes also allow in more butterflies, moths, and dragonflies potentially.


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