Standardized Sampling for Detection and Monitoring of Hemlock Woolly Adelgid in Eastern Hemlock Forests prepared by Dr.

1. Standardized Sampling for Detection and Monitoring of Hemlock Woolly Adelgid in Eastern Hemlock Forests prepared by Dr. Scott Costa, University of Vermont

2. Presentation Goals • Introduce Hemlock woolly adelgid (HWA) • Train HWA samplers

3. Hemlock Woolly Adelgid, Adelges tsugae • Invasive Species • No Effective Natural Predators or Diseases • Explosive Population Outbreaks • Tree Death Shortly Follows

4. Consequences of Hemlock Loss Hemlock is Important • Protects Riparian Zones • Water quality • Water temperature • Provides Animal Habitat • Replaced By • Invasive plants • Less desirable trees • Poor Stand Recovery • Short-lived seeds

5. HWA Lifecycle – Explosive Population Growth • 2 generations/yr • 100+ eggs/adult • Crawlers crawl! • Nymph and adults immobile • Winged adult dead-end

6. Very Small in Summer And very hard to see!

7. A Woolly Eggmass Uncovered

8. Crawlers, Crawlers, Everywhere! • Abundant • Very Mobile • Nearly Invisible

9. Abundant Populations Develop Quickly

10. THE ULTIMATE CONSEQUENCE

11. How do HWA Spread? • Human Activity • Nursery crops • Hemlock logs • Natural • Wind dispersed • Animals: Birds, deer and small mammals

12. How can we find HWA?

13. The Sampling Plan • Monitor spread and level of infestation • Decision making for management action • Assess management success • Research tool

14. A Good Plan • Simple to Use • Practical and Efficient • Has Defined Reliability

15. Specific Goals for Sampling HWA Within a Stand • Detection – Are they out there? • Characterization – What is the level of infestation?

16. Sample Lower Branches • Inefficient to sample above ground level • Data indicates lower branches are suitable

17. COUNTING IS NOT PRACTICAL

18. Woolly Masses - Present or Absent

19. Presence or Absence Sampling Plan Presence or Absence White Woolly Masses Lower Branches NOT Tree Condition

20. Hemlock Woolly AdelgidSampling Plan • Examine 2 branches on up to 100 trees. • HWA can be detected with 75 % reliability when > 2 % infested trees. • Efficient determination of % trees infested using defined precision (0.25).

21. The Hemlock StandLimited stand information requiredStands 10 acres or more, but smaller OK tooStronger Hemlock component is better

22. Where to Sample on Trees • 2 Branches you can reach • Underside of last 1 meter • Ignore foliage quality • Base of needles – follow twigs

23. What to Look For • Any evidence of woolly masses • Large egg sacks • Immature HWA • Scars of woolly masses • No counting • Not the typical HWA picture – initially have fewer HWA

24. The Typical PhotoNOT what you typically see

25. Search Image is Everything

26. Woolly masses Pop out at you

27. Older, Ragged Wool

28. Rapidly Scan Along Twigs

29. Lighting is Important

30. Spittle Bugs Caterpillar Webbing Scale Insects Spider Webbing Mite Webbing Only at base of needles, usually Only on underside, usually If it doesn’t look like HWA it probably isn’t HWA Bag Questionable Samples Especially in Low density Areas

31. Spittle Bug

32. Spider Egg Sacks

33. Scale Insect Floss

34. Pine Aphid Wool Drops of Pine Sap Oak Skeletonizer Spider Egg Sack

35. How to Sample • Pick 4 general areas to sample (blocks) • Go into first block and pick a tree • Examine 2 branches (1 meter long end) • Limit your observation time (<1 min.) • Put results on survey sheet • Go to next tree and sample • Head in random cardinal direction • Go roughly 25 (2 step) paces • Go to next tree >>>>> Next Block

36. THE LAW Once you find ONE HWA on a tree, you are done with that tree!

37. Semi-random Cardinal Path N

38. Sampling Path Flexibility • Straight line vectors • Zigzag vectors • “W” paths • Any tree you can find paths • Object is to get a representative sample by moving through the stand

39. How Many Trees Get Sampled • Detection – Sample until you find HWA or 100 trees, whichever comes first. • Characterization % trees infested – 8 to 100 trees depending on infestation. • Stop thresholds on data sheet.

41. Limits of Minimum Detection

42. When to Sample? Summer Sisten Difficult to Detect

43. How Long Does it Take?

44. Stand is long and narrow A lake in path! 25 (2 step) paces and no tree Low foliage quality The stand ended No opposite branch Blocks overlapped Why avoid summer Stopped sampling before threshold What if HWA dead What if I’m wrong FAQ’s

45. Use a Compass Bug Repellant Water and Snack Dress Properly Be Smart No heroes Know your limits Sample together Stay Safe

46. Forest TrainingPractice in HWA Infested Stand • Raises Questions • Builds Confidence • Develops Proficiency • Fosters Consistency

47. Hope for Hemlock’s future! Biological Pest Management • Insect-killing Fungi • Lecanicillium muscarium • Predators • Sasajiscymnus tsugae: Japan • Laricobius derodontid: British Columbia • Scymnus lady beetles: China

48. Sampling Plan Development • Developed by Scott Costa, Department of Plant and Soil Science, University of Vermont • Research support from Joe Brown and the Harvard Forest Summer Ecology Internship • In collaboration with Bradley Onken, USDA Forest Service Northeastern Area State and Private Forestry • With support and funding from USDA-Forest Service Northeastern Area