OK, there's a number of different ways to sample
for onion thrips in the field.
This is one way that we call it in situ.
That means in place, and so you can just
open up the neck of the onion plant
and look inside and see how many strips you can find.
They're really small thrips.
The early immature stages are very
small and hard to see with just the naked eye,
and so it's often best to have some kind of magnification.
And so just come up to the plant, look inside.
Use the hand lens to help you view the smaller thrips,
and you can get an idea and a count of how many there
are per plant.
So that's one approach.
The approach that I actually like the best
because it gives me a little better view
is to use this magnifying lens.
These are called magnifocusers.
Another method that we use in research to sample onion thrips
numbers on plants is to actually collect a destructive sample.
That is cut the plant and take it
back to the lab where we can wash the thrips off.
So the method we use for this is just
to cut the onion plant right at the base of the plant,
put it inside a plastic bag.
We generally cut multiple plants.
Three or more so that we have a good sized sample.
Put these in a plastic bag that we label with the field ID
information.
So when we get back to the lab, we're
going to use a little bit of soapy water
to wash the thrips off the onion leaves.
So we just use a couple drops of soap and some water,
and you pour--
dump your onion plants into the bucket with the soapy water.
Rinse them thoroughly, washing all the thrips off.
And then we use the 230 mesh sieve so very fine
mesh sieve that's going to collect the thrips on it.
We just pour our solution through the sieve,
including the onions.
Let me rinse them off.
Rinse out the buckets.
RInse the thrips down to one side of the mesh sieve.
We use 70% ethanol, so ethanol that's diluted down to 70%,
and it'll break down that those soap bubbles.
And then a small funnel, and we can wash this solution
with the thrips in it into a vial.
We label the vial with our field information,
and then we can count it under the microscope.
We can take our thrip sample, mix it up.
Pour it into a Petri dish-- plastic Petri dish,
and then we can look through the microscope
and count the number of adult thrips and immatures,
and we can distinguish the difference between onion thrips
and Western flower thrips by some
of their key characteristics.