5. Malaise Traps, Flight Interception Traps, and Pheromones

The first article about insect collecting was, besides other things, about catching of flying insects using an entomological (butterfly) net. There are more methods of catching flying insects. These methods usually save time, because close supervision is not required. They belong to the passive ways of insect collecting (the same as the pitfall traps described in the third article).

A malaise trap placed in the forest

A malaise trap

The device for the catching of flying insects pictured above is a Malaise trap. It was invented by René Malaise.

There are many designs of the Malaise trap available, 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 fluid, which is usually alcohol.

The sleeve with the container filled with killing fluids is the highest spot of the trap. This is because insects tend to crawl upwards. There are two types of Malaise trap: 

• With construction, that is usually made from duralumin pipes. It reminds one of the construction of a normal touristic tent.
• Without construction. This type must be hung from the surrounding trees and anchored to the ground.

As always, very important is the selection of the  right location for the placement of the Malaise trap. The best option is to install it on a spot without high growing herbaceous flora. Other ideal places may be above small streams or on the edges of forests. Ideal is adirection facing the prevailing airflow - so the wind "blows" insects into the trap. This method traps mostly Diptera and Hymenoptera.

Flight interception traps

The second type of traps utilized in order to catch flying insects are flight interception traps. They consist of placing an upright clear barrier under which one or more small basins are placed. The barrier may consist of materials such as plastic mesh, a transparent plastic sheet, etc. Flying insects then hit against the barrier and drop to the basin filled with preservative fluids. This trap works with or without pheromone.

Flight interception traps can be placed on the surface or hung in the trees. Coleoptera is the group of insects most attracted to this type of trap.

Flight interception traps

Author: David Mazáč