Biological Control of Tamarisk Dan Bean Colorado Department of Agriculture Biological Pest Control

1. Biological Control of Tamarisk Dan Bean Colorado Department of Agriculture Biological Pest Control Palisade, Colorado

2. Tamarisk Biocontrol • What is biocontrol and what can we expect from it? • A brief history of tamarisk biocontrol • Monitoring tamarisk biocontrol • Is biocontrol compatible with SWWF habitat?

3. Why are some plants invasive? • Absence of natural enemies. • Unusual genetics, unique strains and hybrids

4. 1 2 Classical Weed Biological Control Tamarix spp The reunification of host specific natural enemies with invasive plants 1850? Saltcedar Leaf beetle 2001 Diorhabda elongata

5. The results of weed biocontrol are a new equilibrium between plant and herbivores herbivore added

6. Weed Biocontrol: what can we expect from it? • Not as good as some believe (or hope for). “No biocontrol agent has exterminated the target weed…” Harris 1988, Bioscience 68 introductions, 24 cases of substantial damage, 6 cases where impact was great 1988

7. Weed Biocontrol: what can we expect from it? • Not as good as some believe (or hope for). • Not as bad as some fear. “No biocontrol agent has exterminated the target weed or a desirable plant” Harris 1988, Bioscience Rhinocyllus conicus The evil weevil

8. Weed Biocontrol: what can we expect from it? • Not as good as some believe (or hope for). • Not as bad as some fear. • Environmentally and ecologically sound, sustainable, cost-effective St. Johnswort suppressed in Northern California

9. Chemical, Biological Cultural, Mechanical balance Weed Biocontrol: what can we expect from it? • Not as good as some believe (or hope for). • Not as bad as some fear. • Environmentally and ecologically sound, sustainable, cost-effective • A valuable tool in an IPM program

10. Tamarisk Biocontrol Timeline Identification of target/background research Overseas exploration and research to find agent or agents (D. elongata and Trabutina mannipara are promising) 1987 Jack DeLoach 1989-1994 TAG approval for both species, 1994 1998-2000 field cage tests and monitoring plan put into place 2001, limited open releases!

11. First Saltcedar Biological Control Agent Released in North America in May 2001 Egg Larva Adult Saltcedar Leaf Beetle, Diorhabda elongata deserticola from China

12. Status of Fukang/Chilik Releases

13. Approved Experimental Release Sites

14. The day length problemThe China population stops reproducing at day lengths less than 14hr 40 min(the bottom line from many experiments)

15. 14hr40min Fukang beetles have a narrow reproductive window in Pueblo and will not reproduce during the summer in Texas

16. Status of Fukang/Chilik Releases 38th parallel

17. Status of Fukang/Chilik Releases 38th parallel Chilik critical day length- 14hr 29min

18. Status of Fukang/Chilik Releases 38th parallel Chilik critical day length- 14hr 29min

19. First ‘implementation’ releases of Diorhabda elongata in the US: early August 2005 Northern California and Texas have beetles from Crete 38°N

20. Short term maintenance of 60,000 beetles at the Palisade Insectary Packaging and shipping to cooperators

21. Successes in Tamarisk Biocontrol

22. Acres Defoliated – 2006(Released in 2001) Lovelock, NV ~85,000 Schurz, NV ~30,000 Delta, UT ~30,000 Lovell, WY ~10,000 Pueblo, CO ~100 Total ~155,100

23. Lovelock Site August, 2003 Point of initial release Photo by A. Brinkerhoff

24. Swarming adults/ defoliating larvae

25. July 2004 10,000 acres defoliated High winds blow dust and Diorhabda over the West Humboldt range

26. Moab, Utah

27. Moab, Utah 2006

28. Potash, 16 miles downstream from Moab. Beetles released in 2004-2005 Initial release point June 17, 2006

29. Williams Bottom, 10 miles downstream from Moab. Beetles released in 2004-2005 Initial Release Point June 24, 2006

30. 6/24/06 First summer generation larvae defoliate at Williams bottom

31. 7/14/06 First summer generation larvae expand across road, photo taken from Amasa Back

32. 7/24/06

33. 7/24/06 Original defoliated zone with regrowth

34. 8/22/06

35. Adult beetles move up and down the canyon, larvae infest most trees

36. Beetles moved out of the canyon and found isolated plants up to 2 kilometers away

37. Beetles defoliate tamarisk, leave willows and other natives to stand out as green foliage

38. Mapping and Monitoring in Tamarisk Biocontrol

40. Navajo Wash Mancos River

42. GPS screen – Knowles Canyon Monitoring ProtocolTamarisk • Site layout: • 25 marked trees • Release Tree • 12 trees 0-100 meter radius • 12 trees 100-200 meter radius • Height, width, tree health, beetle/larval/egg presence, predators, date, person recording data, and a comment field

43. 200 meters

45. “Apparent” Whole-plant MortalityLovelock, NV T. Dudley

46. Birds and Diorhabda in Tamarisk B. Longland, D. Hitchcock Diorhabda present Diorhabda absent 6 3 0 3 Mean No. per Transect

47. Canyonlands by Night Release Site William’s Bottom Release Site Potash Release Site Kane Creek Moab - Defoliated AreaJune - September 26th, 2006 • Total Defoliated Area between Potash and Williams bottom for 2006 • 593.43 acres (240.2 hectares) *Does not include Dewey Bridge or Canyonlands by Night Release sites • Defoliation – September 26,th 2006 • 513.04 total acres defoliated • 18.5 Total river miles Canyon Mouth

48. Mapping and monitoring the spread of Diorhabda. The beetles will enter Colorado, from Moab, in 2007 Pheromone based monitoring GPS/GIS based mapping

49. Release of Diorhabda beetles throughout the range of tamarisk 1. Need beetles that will reproduce at southern latitudes 2. Need to resolve SW willow flycatcher issue

50. Release of Diorhabda beetles throughout the range of tamarisk 1. Need beetles that will reproduce at southern latitudes OK 2. Need to resolve SW willow flycatcher issue