1. Complimentary materials
Wood with Sirex wood wasp damage
Wood with other wood wasp damage (if we can find this at U of MN).
Adult and larval Sirex wood wasps
Adult non-target wood wasps
Wood with pine sawyer damage
Adult and larval pine sawyers

2. Wood wasps / Horntails 1 to 1.5 inches long
Schiff et al. 2006
1 to 1.5 inches long
“Horn tail” and lack narrow “waist”
23 species in US and Canada
2 on hardwood, on softwood
19 native, 4 exotic

3. Which insect is a wood wasp?
N. Wright, FDACS, Bugwood.org
F. & K. Starr, U.S. GS, Bugwood.org
G. Alpert, Harvard Univ., Bugwood.org

4. The Sirex Woodwasp ● 1 to 1.5 inches long
K. E. Zylstra
K. E. Zylstra
The Female
The Male
● 1 to 1.5 inches long
● Dark metallic blue-black body
● Legs reddish-yellow, feet black
● Antennae entirely black
Similar to females, but…
● Middle portion of abdomen
orange
● Hind legs black

5. K. E. Zylstra

6. Which insect is the Sirex wood wasp?
N.Wright, FDACS, Bugwood.org
PDIL, Bugwood.org
PDIL, Bugwood.org

7. The Larva ● Creamy white ● Legless ● Dark spine at tip of abdomen
K. E. Zylstra
The Larva
K. E. Zylstra
● Creamy white
● Legless
● Dark spine at tip of abdomen

8. Siricids are commonly referred to as horntails because of their cornus on the posterior end
Currently, there is no morphological key for siricid larvae and a molecular key is being developed by the USFS.
K. E. Zylstra

9. Which larva is a wood wasp?
D. Cappaert, MI State Univ., Bugwood.org
H. Pase III, Texas F.S., Bugwood.org
S. Kinelski, , Bugwood.org

10. Finely packed frass in the tunnel
K. E. Zylstra
When you cut through the tree sometimes you can see where you cut through a gallery
K. E. Zylstra
Finely packed frass in the tunnel

11. Larval Galleries
K. E. Zylstra

12. K. E. Zylstra
K. E. Zylstra
Larval galleries

13. Adult male chewing his way out…
K. E. Zylstra

14. Symptoms of Attack Resin beads Browning/thinning crown
Woodpecker damage
Exit holes
***The Sirex wood wasp can attack living trees, while native wood wasps attack dead or dying trees***

15. Resin Beading Looks Different On Different Pine Species…
Red Pine
Scots Pine
White Pine
Resin beads
K. E. Zylstra

16. Infested Scots Pine
K. E. Zylstra
K. E. Zylstra

17. Infested Red Pine
K. E. Zylstra
K. E. Zylstra

18. Infested White Pine
K. E. Zylstra
K. E. Zylstra

19. K. E. Zylstra
Exit Holes Perfectly circular, size ranging from 1/8 to 3/8 inch diameter
K. E. Zylstra

20. K. E. Zylstra

21. Which holes are Sirex wood wasp
exit holes?
J. Hodge, Univ. of Kentucky, Bugwood.org
R.. Billings, TX F.S., Bugwood.org
D. Haugen, U.S. F.S., Bugwood.org

22. K. E. Zylstra
K. E. Zylstra