About The Sirex Woodwasp

What is the Sirex Woodwasp?

The Sirex Woodwasp (Sirex noctilio) is one of the 150 non-social species of horntail wasps in the Siricidae family. Woodwasps hatch from eggs that have been laid in any species of pine tree (New York Invasive Species). The Sirex Woodwasp originated in Eurasia and North Africa (“Pest Alert” 2005). However, it has begun to spread around the globe, causing harm to many ecosystems it invades.

Where is the Sirex Woodwasp invasive?

The Sirex Woodwasp has been accidentally introduced to several continents, including Australia, South America, and North America, and has a growing presence in the Adirondack Park (New York Invasive Species). First identified in North America in Fulton, New York in 2004, the Sirex Woodwasp was accidentally introduced to the region via imported wood products and has been sighted in various north-eastern locations since then (“Proposed Program” 2008). While some species of woodwasps are native to the Adirondack Park, native woodwasps target dead or dying pine trees, while the Sirex Woodwasp has a strong affinity towards living pine trees and requires a habitat rich in pine to thrive (“Sirex (European) Woodwasp”). However, the Sirex Woodwasp has a significant impact on living pine trees, and has lead to the death of million pine trees throughout North America (New York Invasive Species). To learn more about the spread of the Sirex Woodwasp, read “The Sirex Woodwasp as an Invasive Species” page.

How can I identify the Sirex Woodwasp?

The adult Sirex Woodwasp is bluish-black in color and is typically 1 to 1.5 inches long (“Pest Alert” 2005). Males have orange mid sections with black legs, while females have a blue-black abdomen and orange legs (“Pest Alert” 2005). Both males and females display yellowish wings. The Sirex Woodwasp should not be mistaken for other woodwasps that are indigenous to the Northeastern United States.

Adult Male Sirex Woodwasp (U.S. Dept. of Agriculture, 2016).
Adult Female Sirex Woodwasp (U.S. Dept. of Agriculture, 2016).

How does the Sirex Woodwasp grow and reproduce?

Much like the life cycle of a ladybug or butterfly, the Sirex Woodwasp transitions through complete metamorphosis, as shown below.

Life cycle of the Sirex Woodwasp. (Image from Mail & Guardian, produced by John Mccann 2015).

In one season, a female Sirex Woodwasp will produce between 25 to 450 eggs (“Sirex Woodwasp”). During reproduction, a female Sirex Woodwasp will dig small, round holes through the bark of healthy pine trees, then deposit her eggs safely into these holes. In July, adult woodwasps emerge from the pine and continue the annual lifecycle process (“Sirex Woodwasp”).

What does the Sirex Woodwasp eat?

Adult Sirex Woodwasps are thought to eat the sap, or liquid, inside the xylem of pine trees. As larvae, woodwasps only eat Amylostereum areolatum, a fungus that the mother deposits into the pine trees with her eggs. This fungus can be very harmful to an otherwise healthy pine tree, and can cause significant negative consequences in ecosystems where the Sirex Woodwasp is not native. 

Works Cited:

New York Invasive Species. “Sirex Woodwasp.” New York Invasive Species. Cornell University. 2016. Web. 1 March 2016.

“Sirex (European) Woodwasp.” Adkinvasives.com. Adirondack Park Invasive Plant Program. 2016. Web. 1 March 2016.

“Sirex Woodwasp.” Invasives.org. Center for Invasive Species and Ecosystem Health. 4 May 2010. Web. 1 March 2016.

“Proposed Program for the Control of the Woodwasp Sirex noctilio F. (Hymenoptera: Siricidae) in the Northeastern United States.” United States Department of Agriculture. USDA, August 2008. Web. 1 Mar. 2016.

“Pest Alert: Sirex Woodwasp – Sirex noctilio F. (Hymenoptera: Siricidae).” United States Department of Agriculture. USDA Forest Service. June 2005. Web. 19 April 2016.