I'm Ricardo Ramirez, Extension Entomologist
at Utah State University.
And today, we're here at Greenville Research Farm
in Logan, Utah.
It's June 29, 2016.
And in this video fact sheet, I'll
be discussing how to make pitfall traps
to monitor billbug activity in the Intermountain West.
Billbugs are an important pest in turfgrass
in the Intermountain West and other regions of the United
States.
In our region, billbug larvae are
considered to be the damaging life stage as they feed
within stems and also on roots.
However, we can use adult billbug activity
as a monitoring tool to make management decisions early
in the field season.
One of the ways that we can do this
is by the use of pitfall traps.
And so we'll start to make a couple of different designs
of pitfall traps.
So let's get started.
The first pitfall trap design is pretty simple.
It actually just consists of a couple of plastic cups.
And so you'll need a trowel, a shovel, or a cup cutter
in order to dig a hole.
And that'll be the first step, making
sure to dig the hole that's deep enough and wide enough
to fit one of these cups snug into that hole,
making sure that the lip of the cup
is actually flush with the soil surface.
So as you backfill with soil, and you
start to pack that soil down, that you'll
start to create a funnel effect that'll
make its way into the mouth of that cup.
Now, once you've done that, with the second cup,
you'll want to use some scissors to cut the lip of the cup off.
And so that way you create a removable sleeve.
So now this sleeve can actually fit into the pitfall cup--
pitfall trap.
And so the way that this works is you'll
have soil-active insects and other arthropods crawling.
They'll fall into the trap.
And then you can check the sleeve regularly
as those insects fall into this, billbugs in particular.
You can transfer the sample into a plastic baggie.
So one of the modifications that you can make to this simple cup
pitfall trap is to make some small holes at the bottom
of the pitfall trap cups.
That way any water from rain or from sprinklers
will actually drain out of the cup,
and that your samples won't be flooded.
Be aware that pitfall traps aren't specific to billbugs.
So they're going to collect a lot of different types
of insects and arthropods, like predatory ground beetles
and spiders.
So it's important to have some general knowledge of the target
pests that you're looking for.
So that way you're making management decisions
on that target pest.
So the linear pitfall trap is a more complex trap
because it has a lot more parts, but it also can detect activity
in a larger area.
And so the linear pitfall trap consists of an irrigation box
with a lid.
Also, a PVC pipe, this one is 2 inches.
It also has a length of about 3 feet.
You'll want an end cap to cap off one end, and then
a 90-degree angle elbow here to actually
be able to attach our pitfall trap cup.
And so this is the collection cup.
And it can either be a plastic food
container or a small plastic coffee container with a lid.
They'll need to be some special cuts made.
The first one will consist of a hole as close
to the top of the irrigation box,
so that you can fit the 2-inch pipe into that irrigation box.
You'll also need to use a drill to drill out about a 1/4 inch
to 3/8 inch slit or groove down the length of this pipe.
Now, I have left a couple of areas with a PVC pipe.
This one's about 1 inch.
And this helps to keep the structure of the pipe.
With thinner-walled PVC pipe, sometimes you
get some twisting.
Now, the final cut will be made with the lid--
or on the lid of this plastic container.
And so this is so this will fit snug inside
of the irrigation box and onto the elbow of the PVC pipe.
Because the linear pitfall trap is housed in an irrigation box,
it's actually inconspicuous in recreational areas.
So it actually fit in pretty well.
To install the linear pitfall trap,
you'll want to dig a hole deep enough
in order to fit the irrigation box where the lid is just
flush with the soil surface or nearly flush
with the soil surface.
In addition to that, the pipe will also
need to be dug in to be level with the soil surface as well.
A couple of things that you want to be sure of
is that the slit within the pipe is facing upward.
And also that you have a slight tilt to the PVC pipe,
so that any water that gets into the pipe
will actually drain into the irrigation box.
Then you'll want to backfill, packing down that soil
so that it's even or flushed with the slit
and also with the irrigation box lid.
When you're selecting a place to put your traps,
think about areas that you've had problems
with billbugs in the past, some hotspots
in the roughs of golf courses.
And so as you start to select those places,
you can look at field edges, the roughs of golf courses,
near refuge sites.
Billbugs overwinter, as adults primarily,
in these refuge sites and then will make their way
into turf grass.
So it's nice to have a trap parallel to that area.
We often collect our traps about once a week, particularly early
in the season, spring.
Billbugs become active as early as February in our region.
But typically, we see an increase
in their activity from April to about June.
The larvae of the billbugs actually lag behind
by about a week or two.
It'll be important to pair adult monitoring
with larval monitoring and also with predictive degree-day
models as they become available, so that we
can make a better informed decision on how
to manage these insects as they become problematic.