Biology OCR As transport in phloem - aphids

I have just come across this experiemtn and i have no idea how it works its afhids feeding on a plant stem and leaving honeydew which is meant to show the speed of transport in the ploem
:confused:

Reply 1

corkskrew

phloem is where the aphids feed from. Basically you let an aphid or a bunch of aphids feed on the plant then you brush them off, snapping them at the proboscis (beaky nose thing). This leaves a nice little tube into the phloem, a bit like a straw. Movement in the phloem means the fluid moved also comes out of the remaining proboscis.

Reply 2

oxfordbrooks

and how do u measure the speed of flow then ??????

Reply 3

Eternal Fantasy

oxfordbrooks

and how do u measure the speed of flow then ??????

You collect the sap. The more there is, the faster the speed of flow.

Reply 4

oxfordbrooks

i thought so thank you everybody

Reply 5

corkskrew

Not my syllabus but just had a look in my text book which covers biology up to about 2ndyr of degree level. It is possible to attach mini pressure gaugues to the stylets and get a reading in pascals.
I dont see why you couldn't inject a dye at a known distance from a stylet and measure the time it takes to move that distance.
Interestingly, you let the aphid attach to the plant stem and anaethetise it with CO2. Poor sods.