There was an old woman who swallowed a fly..

After a couple of days of blisteringly hot weekend sun, what better way to spend a Monday afternoon than by sampling insects collected from the Plants for Bugs plots!

In a past post, I mentioned that one of our five invertebrate sampling methodologies involves the use of pitfall traps to collect invertebrates active on the ground.  To record those that remain largely on the foliage, we use a Vortis suction sampler.

 

 

 

 

 

 

 

 

 

 

 

RHS Senior Entomologist Andy uses a Vortis suction sampler to collect insects on the foliage

 

To understand how it works- imagine an upright bagless vacuum cleaner and you’re not far off.  Designed to extract insects from the foliage, this petrol-powered picker-upper sucks up invertebrates from the leaves (see below left, in action) and deposits them unharmed (if a little disorientated) in a collecting cup (below right).

Once collected, each sample is returned to the lab for an initial sort. This separates living insect material from plant detritus. A similar process of suction sampling is used again, only on a smaller, more delicate scale.  Gone is the 8 kilogram Vortis and in its place, the humble pooter.

 

Comprising a rubber bung, two plastic tubes and a collecting jar, pooters are often used by entomologists in the field to remove insects from foliage.

The diagram on the left illustrates how the process works. Air is drawn in by sucking on rubber tubing attached to the straight plastic tube. This draws the invertebrates in through the other (bent) tube.

The discerning amongst you will notice that only a small piece of mesh prevents the entomologist from swallowing the sample. You’ve got to be pretty unlucky (and/ or stupid) to use the wrong tube but when you’ve got a handful of angry harvestmen in your collecting jar, the mistake suddenly seems an easier one to make – that’s my excuse anyway!

If I need to swallow a bird to catch the spider, I’m going to need a bigger pooter..

2 thoughts on “There was an old woman who swallowed a fly..

  1. I’ve been trying to source a supplier for the ‘Vortis suction sampler’. Can you tell me where you got yours from, please? Cheers

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