Method III „Light-Trap"


Lichtfang in FR.-GuyanaAnother method which enables to collect special species spectrums, is the use of a light-trap which is due to being exceptionally sufficient for these insects broadly used by entomologists studying flying insects such as Lepidoptera, Coleoptera, Ensifera or Heteroptera. This method is however not very sufficient for phasmids and usually the collected insects restrict to single specimens of well-flying species which may not ber found with method No. I or male specimens. Generally males show a stronger tendency of being attracted to light and in some cases the numerous other insects may be more interesting than the single phasmids.


Lichtfang in WestmalaysiaThe function of a light-trap is quite simple. One needs a strong light-bulb (if possible a superactinic bulb or black-light), which is supplied with electricity by using a generator and a large white, reflecting surfaces (a white sheet or a wall). Slightly raised clearings or forest boarders have proven to be the most sufficient localities, due to enabling the insects to see the light from far distance. The most prolific time-span in the tropics seems to be between 11 and 12 pm. 

 

When the light-trap is completely installed, patience is needed. Often it takes hours that, except from incountable other insects, the first phasmid is attracted by the light. Is is also a good idea to search the surrounding vegetation as well, as some insects may not directly sit on the enlighted surface but on the slightly enlighted shrubs nearby.

Lichtfang in Französisch-Guyana

 

Generator Honda 10iRecommended equipment:

A portable generator (e.g. Honda 10i), a strong superactinic or black-light bulb, white sheet or similar, a stable but lightweight frame, ropes for fixing the reflecting surface, differently sized plastic containers, and a net with an extendible handle.
Alternatively, a complete, professional light-trap or “light-tower” may be purchased from most entomological suppliers in Europe.