Purple panel traps can help trap and monitor wood boring beetles (buprestid species) in your nursery or orchard, including but not limited to Flatheaded Appletree Borer (Chrysobothris femorata), Pacific Flatheaded Borer (Chrysobothris mali), and Emerald Ash Borer (Agrilus planipennis). Install the traps near your trees in late March or April. Most buprestids emerge around May or June, so having the traps ready is important to determine when they emerge. Adult emergence informs the overall pest management system in place. Below are two designs for traps, near the ground for flatheaded appletree borer, Pacific flatheaded borer, or elevated for emerald ash borer.

Use the materials list for both types of traps illustrated below (Figure 1).

The prices below were retrieved from Amazon, Greatlakesipm, or Hummert at the time of publication (2025). Availability and cost of items may vary or be obtained from any source.

Materials

1. Corrugated plastic panel (Figure 2)
   It should be roughly 1’x 3,’ though size can vary. The example below is a single sheet that can be cut into thirds. White panels may be easier to procure, though they need to be painted purple. Buying panels that are already purple is another option.

   • White panels were $48.88 for 10 to make 10 traps.

   • Purple panels were $97.71 for 4 to make four traps.

2. UV-resistant zip ties to fasten panels together (Figure 3).

   • Zip ties were $8.99 for a 100-pack.

3. Pestick compound to coat prism traps and cause arthropods to stick to the panels (Figure 4). Do not use tree tanglefoot.

   • Pestick was $63.50 for a quart (1.625lbs).

4. Purple paint to attract the insects (Figure 5). Use exterior latex paint.

   • Purple spray paint was $10.29 for 12oz that covers 12 sqft. To make 10 traps, three cans of paint are needed. Quarts or gallons of exterior latex paint can also be used.

5. Wooden stakes to provide structural support (Figure 6).

   • Four foot landscape wooden stakes were $44.99 for a 25-pack.

6. Hole puncher to modify the panels (Figure 7).

   • Hand held ⅛ inch hole puncher was $29.95.

7. Black trash bag, landscape fabric, or weed barrier to demarcate the trapping area and catch partially stuck beetles that might have fallen (Figure 8).

   • Black trash bags were $11.01 for a 25-pack.

8. Ground staples to install the landscape barrier into the ground (Figure 9).

   • Six inch ground staples were $9.99 for a 50-pack.

Total Estimated Cost: $20-$23 per trap based on $200-$230 for ten traps, though most materials can be reused for future traps. Feel free to improvise within reason to save cost.

Figure 1. Entire materials List

×

Figure 1. Entire materials List

Print Image

Figure 2. Corrugated plastic poster board

×

Figure 2. Corrugated plastic poster board

Print Image

Figure 3. UV-resistant zip ties

×

Figure 3. UV-resistant zip ties

Print Image

Figure 4. Pestick

×

Figure 4. Pestick

Print Image

Figure 5. Purple paint

×

Figure 5. Purple paint

Print Image

Figure 6. Wooden stake

×

Figure 6. Wooden stake

Print Image

Figure 7. Hole puncher

×

Figure 7. Hole puncher

Print Image

Figure 8. Trash bags

×

Figure 8. Trash bags

Print Image

Figure 9. Ground staples

×

Figure 9. Ground staples

Print Image

Best for: Flatheaded appletree borer, Pacific flatheaded borer.

Construction

1. Optional: You may paint the white sheets purple before you begin the process. Only one side (exterior side) needs to be painted. If trapping emerald ash borer, paint both interior and exterior sides.

2. Take one panel and score it lengthwise along the flutes, as shown below. Take care to score the painted side if it is already painted. This lets you fold the panel without using extra zip ties. If you accidentally cut all the way through the panel, you can zip tie them together at a later step, no harm done (Figure 10). This doesn't have to appear perfect, beetles are attracted to the color purple that appears the width of a tree trunk.

3. Punch three holes along each side of the panel, as shown (Figure 11). Take care that the holes align. If it helps, you can fold the panel for reference when punching out holes.

4. Fold the panel into thirds and zip tie the holes together (Figure 12).

5. Weed thoroughly around the desired location of the trap in a diameter of at least two feet, and place a black trash bag over the cleared space. This helps with catching insects that might struggle free of the sticky trap.

6. Drive the wooden stake into the ground through the trash bag, then slide the prism over the pole. It does not have to be affixed to the stake, though you may attach it if you feel comfortable with approach. This location, approximately 3 feet continuously from the ground up, reflects where flatheaded appletree borers might choose to lay an egg on the tree trunk (Figure 13).

7. If using white panels and paint, apply a thorough layer of purple paint to the entirety of the panels. Wait to dry. Apply a second coat.

8. Apply Pestick to the entire surface of the panels in accordance with the instructions on the label. FOLLOW ALL INSTRUCTIONS ON THE SAFETY LABEL.

Check regularly and take care to properly identify the beetles present. Use this reference to identify the beetles. When mowing nearby, use care to direct clippings away from the trap; otherwise, grass clippings on the trap will prevent beetles from adhering to it.

Figure 10

×

Figure 10

Print Image

Figure 11

×

Figure 11

Print Image

Figure 12

×

Figure 12

Print Image

Figure 13

×

Figure 13

Print Image

Best for: Emerald ash borer.

Construction

1. Optional: You may paint the sheets before you begin the process. Both sides need to be painted.

2. Cut 1 panel into thirds of equal size (Figure 14).

3. On each panel, punch one hole on each corner. Make sure all punches align (Figure 15).

4. On one panel, punch eight total holes, four holes on the corner, and four holes in top and bottom center to affix to the stake. The distance of center holes punched should be equal to the width of the stake that you will be using (Figure 16). Use the stake as a guide.

5. Weed thoroughly around the desired location of the trap in a at least a two foot diameter and place a black trashbag over the cleared space.

6. Drive a wooden stake into the ground through the trash bag in the place where you are installing the trap. This helps with catching insects that might struggle free of the trap (Figure 17).

7. Tightly attach the central panel to the stake. The panel should not slide up or down (Figure 18).

8. Connect the remaining panels to create a triangular shape. Do not overtighten. Once assembled and placed in the landscape, the trap should appear as in Figure 19.

9. If using white panels and paint, apply a thorough layer of paint to the entirety of the panels. Wait to dry. Reapply a second coat.

10. Apply Pestick to the entire surface of the panels, inside and out in accordance with the instructions on the label.

    Follow All Instructions on the Safety Label

11. Check weekly and collect beetles to store and identify if possible.

Figure 14

×

Figure 14

Print Image

Figure 15

×

Figure 15

Print Image

Figure 16

×

Figure 16

Print Image

Figure 17

×

Figure 17

Print Image

Figure 18

×

Figure 18

Print Image

Figure 19

×

Figure 19

Print Image

Amazon

Great Lakes IPM

Hummert International

The Flatheaded Borer Working Group

This video offers a visual representation of the trap construction process:

Edwards A, Senter A, LeBude AV, Addesso K, Deem MJ, & Baker P. 2025. How to make a purple prism trap to monitor emergence of adult metallic wood boring beetles (Buprestidae) in specialty tree crop production. North Carolina A&T State University and NC State University Cooperative Extension. Stopfhb.com