From the field: Collecting insects in mangroves

I started my PhD in Evolutionary Biology Laboratory at National University of Singapore. Our lab’s primary interest is in the Sepsidae family (a.k.a black scavenger flies) which has more than 300 described species. The main reasons for studying these organisms are that many species possess fascinating morphological and behavioural characters, can be easily bred under laboratory conditions, and have short development times. In our lab, the evolution of sexual dimorphisms and mating behavior of flies are intensively studied [1].
In order to do basic science on insects, there is a need for continuous species input from both inside and outside of Singapore. For instance, one of my colleagues just got back from a field trip in Africa, where he collected several fly specimens. There are various methods for collecting insects. When I was a field research assistant in wetland restoration project at KuzeyDoga Society in Kars, we used home-made sticky traps [2].
Bilge nin
Sticky traps are useful for monitoring an area for crawling insects 24/7, however their best use is to collect large-sized beetles. Thus, they are not very good when it comes to detecting small insects or mite pests. You can see an example to sticky traps in the picture above.
For the current fieldwork, our insectory lab is using the Malaise trap, named after its inventor René Malaise. This large, tent-like structure can have various colors and is used for trapping flying insects, in particular Hymenoptera and Diptera [3]. As I explained in the video below, the insects fly into the tent wall and are funnelled into a collecting vessel attached to highest point, which then are directed into a cyclinder or a bottle containing a killing agent, such as ethanol or cyanide.
The orientation of the traps is very important. The opening of the trap should be wide enough for allowing high number of insects to pass through. For instance, if there is a wide corridor in a forest, the trap should be positioned with its opening to the corridor. Upper sections of small streams or the edges of forests are some other examples to ideal trap locations. Our field work was in mangrove forests, which are the characteristic forest ecosystems of tropical and subtropical intertidal regions.
Given that the mangroves consist of several habitats such as salty branches and entangled roots, they are teeming with life, respectively. The mangrove biome is characterized by depositional coastal environments with species adopted to harsh environment conditions such as extreme salinity, temperature and high tides. Mangroves dominate three-quarters of tropical coastlines [4].
In the following video that is recorded by my colleague Gowri, you can see a tiny bit of mangrove forests and my effort to reach the malaise trap located in this muddy environment. Enjoy!
Special thanks to Gowri Rajaratnam and Evolutionary Biology Lab.
1- Evolutionary Biology Laboratory, National University of Singapore:
2- KuzeyDoga Society:
3- Gressit, J.L ve Gressit, M.K. (1962). An improved Malaise Trap. Pasific Insects 4 (1). 87-90.
4- Giri, C., Ochieng, E., Tieszen, L.L., v.d. (2011). Status and distribution of mangrove forests of the world using earth
observation satellite data. Glob. Ecol. Biogeogr. 20, 154-159

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