Willow Tree Borers: Sapsucker Holes vs. Insect Damage

Decoding Willow Trunk Holes: Borers, Not Birds

A willow with white substance (sawdust/sap) over holes, attributed to yellow-bellied sapsuckers, actually has borers—the birds are just exploiting them.

The Real Sequence

1. Borers (likely Cryptorhynchus lapathi - poplar/willow borer) tunnel in trunk/branches.
2. Tunneling produces white sawdust (willow wood is white) + sap = the "white substance."
3. Sapsuckers detect borer activity, enlarge holes to eat larvae.
4. Birds are secondary—they follow the borers.

Why Grandma Didn't See Birds

• Sapsuckers feed quietly, early morning/late evening.
• They may visit briefly during migration.
• Holes remain long after birds leave.

Treatment Options

1. Borer spray: Ferti-lome Borer, Bagworm, Tent Caterpillar, Leafminer Spray (permethrin) on trunk and accessible branches. Follow label.
2. Systemic soil drench: Imidacloprid labeled for borers on non-edible trees. Willow = non-edible, so acceptable.
3. Manual probing: Wire into holes to kill larvae (tedious, limited reach).

Critical Cultural Care

• Water deeply during drought—willows need consistent moisture.
• Avoid stress: No root disturbance, no herbicide near trunk.
• Monitor: New sawdust = active borers. Re-treat as needed.

Willows are tough. With borer control + good water, this tree should recover fully.