Collecting

Beetles may be collected from the field in a number of ways.  As well as collecting by hand, beetles may be sucked up with a pooter, beaten from vegetation onto a plain white sheet, prised out of wood with a knife or swept with a sweep-net.  If you want your data to be useful, it is imperative that you remember take a note of all site information. Please follow this link to the 'Recording' page to see what information must be collected.

Although some beetles can be identified from photographs, the majority of species must be examined under a microscope for a positive identification. Unless you can capture fine detail on a picture, photographs are generally only useful for backing up actual specimens and for pleasure. Unfortunately it is usually necessary to kill beetles in order to identify them. An alternative is to cool them in the fridge for a couple of hours so you can look at the sluggish specimen under the scope before releasing it (this will not harm the beetle!) Whilst I do not like killing beetles, I feel that in order to learn more about them and thus better protect species' as a whole, it is acceptable to take sample specimens. However, every specimen I kill, I make sure that I identify and use the knowledge it has given me in order that I have not killed it for no reason.

When collecting beetles, you need to ask yourself why you want them. Is it to create a collection? Or perhaps to use the data to build up county records.  However, if you want to ask questions, such as if one site is more diverse than another or if certain dung beetles prefer cattle dung or horse dung then you need to think more carefully about your collection methods. Techniques must be quantitative so that it is feasible to really make a comparison, other factors influencing your results must be taken into consideration, such as time of day, weather, vegetation height etc. Prior to carrying out your experiment, you must consider the statistics you will use on the data and if you have enough repeats of your experiment. It is always a good idea to check your method with someone else before you begin your fieldwork-it is terrible to realise half way through that your data is useless!

Traps are a very good way of encouraging beetles to catch themselves.  Pitfall traps are the most widely used and effective beetle traps, as they sample a wide range of species that are often not found whilst hand-collecting.  They may be used with or without a bait.    A basic pitfall trap is a plastic cup, which is sunk into the ground so that its top is level with the surface.  Beetles may be collected live, or killed in the trap.  To kill everything that falls in the trap, fill the cup to about an inch high of antifreeze (ethylene glycol) and add a couple of drops of detergent to stop the beetles floating.  A "roof" can be erected to keep rain out.  Simply use garden stakes to position a paper plate over the trap, leaving a good 10cm between it and the ground.  A series of 5 or 10 traps (at least 2m apart) is best set out in any one locality, either in a grid or in a line.

Baited pitfall traps also produce interesting finds.  Placing rotting fruit/vegetables/ fungi/carrion in a pitfall trap will attract a diverse fauna. However, do not put a killing agent in the trap with the bait!  Live specimens must then be removed from the trap by hand on a daily basis.  Dung (usually 30g) may be placed in a trap, or suspended in a cheesecloth bag above it (this allows a killing agent to be placed in the trap).  A number of interesting dung beetles should be attracted:  Do remember to note the type of animal from which the dung originated, as many dung beetles are specific to certain types of dung!

Another fool-proof method of catching dung beetles is to simply pick fresh dung pats from pasture and homogenise them in a bucket of water: all insects will float to the top, where they can be sifted off! This a another quantitative collecting method, as the number of pats collected from any site can be standardised, and the number of dung beetles collected can be compared between sites. Collecting 10 ‘normal' sized pats per site is usually about right. A rather smelly, but productive collecting technique!

Flight intercept traps produce specimens that are not normally encountered by other collection methods.  A sheet of black polyester marquisette material can be suspended vertically between two stakes or trees.  A line of containers filled with killing fluid should be placed under the trap, so that beetles fly into the sheet and fall into the containers.

There are also many other ingenious trapping methods. Piles of fungi and decaying fruit/vegetables can be left and regularly sifted over weeks.  Carrion may be placed on the top of a tin filled with sand, which can be sifted through often to find a very rich fauna.  Lawn mowings may be placed in paper sacks or plastic bags for a few days to rot, and then placed in piles at the base of trees.  After a week or so and at intervals thereafter, the pile can be sifted. Another great collecting method is with a suction sampler, which is basically a garden leaf hoover with a fine mesh net covering the end! A standard ‘30-second suck' at each sampling site allows this method to be used quantitatively, and you often find insects not collected with other methods.

In order to examine beetles it is necessary to kill them.  I find that the easiest, most humane way of killing them is by dropping them into a tube of 70% alcohol or antifreeze (ethylene glycol).  They may also be killed in a killing jar.  This can be made by casting a layer of plaster of paris at the bottom of a glass jar.  The plaster will absorb a killing agent, such as ethyl acetate.