Sapsucking Insects

1. Sapsucking Insects

2. OBJECTIVES OF SAPSUCKING INSECTSAt the end of this section students should be able to:1) Describe the symptoms and damage of sapsucking pests.2) List the major types of sucking pests and give example of one of each type that is important in commercial or urban forests.3) Explain why control of these pests is so difficult.4) Describe the relationship between some sapsucking pests and forest pathogens.5) Describe control approaches used in management programs for these pests.

3. Sapsucking Pests Sapsucking pests are Homoperta & Hemiptera Sapsucking pests are also Arachnida (mites) Sapsucking pests have piercing-sucking mouthparts Sapsucking pests are difficult problems Because they are: 1) Inconspicuous 2) Hard to control Sapsucking pests rarely kill trees Scale insects, some adelgids are the exceptions

4. Population Dynamics – P/S Insects Insect populations are affected by: 1. Destruction of natural enemies 2. Dust accumulation 3. Very cold weather 4. Dispersal (wind, people, quarantines) 5. Plant Resistance

5. 1.Numbers increase dramatically when insecticides are used as often they kill beneficial insects more effectively than the pest. 2. Numbers increase when dust accumulates on plants as dust interferes with natural enemies searching ability 3. Plant Resistance reduces population numbers. Sometimes only reasonable approach to controlling sapsucking pests 4. Numbers decrease in very cold weather as this kills individuals and reduces quantity quality of food supply 5. Natural dispersal by wind, crawling, flight. Most major pests introduced on infested nursery stock so quarantines significantly reduce spread

6. Symptoms and Damage 1) Damage from removal of nutrients and toxic saliva Discolored and/or curled foliage

7. 1) Damage from removal of nutrients and toxic saliva Abnormal shoot growth

8. 1. Damage from removal of nutrients and toxic saliva Premature leaf drop

9. 1) Damage from removal of nutrients and toxic saliva Branch and/or tree mortality

10. 1) Damage from removal of nutrients and toxic saliva Adelgid Caused Mortality on Fir

11. 2. Damage from excretions Honeydew and/or black mold on foliage

12. 3. Damage from oviposition activities Cicadas, tree hoppers, sawflies Tree crickets

13. Cicada oviposition damage

14. 4. Disease Transmission Aphids and Leafhoppers

15. 4. Disease Transmission Elm Phloem Necrosis my kill more elms than Dutch Elm Disease Cause: A Phytoplasma Vector: Leafhoppers Characteristic “butterscotch” Discoloration of inner bark

16. Common & Important / Unimportant Sapsucking pests • Asian Hackberry Woolly Aphid • Gall Forming Insects • Hemlock Woolly Adelgid • Spruce Adelgid • Beech Bark Scale • Saratoga spittlebug

17. Hemiptera Aphids - Many species and types Alate (winged) aphid Apterous (non-winged) aphids Cornicles

18. Asian Woolly Hackberry Aphid

19. Pine Aphids (Cinera spp) White pine aphids

20. Spruce Aphids

21. Spruce aphid damage

22. Gall Forming Insects • Tend to be host specific • Interesting life cycles • Leaves, twigs, stems, petioles • Unsightly • Urban vs Forest settings

23. Hackberry gall psyllid

24. Aphid Galls on Hickory

25. Vagabond gall aphid Poplar Petiole gall aphid

26. Oak Sower Gall (a Wasp Gall)

27. Spruce Gall Adelgid

28. Hemiptera: Adelgids - many species Once called aphids Differ in insect: Morphology - no cornicles Life Cycle - always lay eggs Hosts - only conifers

29. Adelgids Hemlock Wooly Adelgid Accidentally introduced to PNW - 1920’s Found in Virginia in 1953

30. Adelgid Bole infestation

31. Hemlock Woolly Adelgid Feeding causes needle drop. Complete defoliation & death of tree. Can kill a tree in a single year

32. Introduced Predator of Hemlock Woolly Adelgid

33. Video – Hemlock at Risk

34. Management - Hemlock Woolly Adelgid Private vs Public Lands

35. Balsam Woolly Adelgid • Another conifer pest killing trees • Imported pest from Europe • Weakens and/or kills true firs • 1 of most important sucking pests • 2- 4 generations / year • No Males Known to exist • Few economical controls

37. Balsam Woolly adelgids – Feeding on tree trunk

38. Feeding Damage Bole infestations cause formation of reddish colored compression wood Poor H2O conduction qualities Toxic saliva causes increase in cell number cell size thickened cell walls and tracheids

39. Butterscotch wood of a balsam woolly adelgid infested tree

40. Feeding Damage Heavy crown infestations cause formation of twig gouting and reduces new shoot growth and eventual death of the tree

41. Impact on true firs in North America is severe • Complete stand mortality • Significant timber losses • Reduced tree growth • Reduced seed production • Killed millions of board feet • Management & Control in US • Few controls available

42. Pine bark adelgids – native insect Found throughout North America Attack Scots, jack, pitch, white and Ponderosa pines Stunt growth, produce honey dew, & occasionally kill trees Spread is slow due to reduced mobility

43. Pine bark adelgid

44. Hemiptera - Scale Insects Soft Scales – cottony, waxy Armored Scales – hard covers Eriococcid Scales Margaroid Scales

45. Cottony Maple Leaf Scale

46. Cottony Cushion Scale

47. Tortoise Scale and Sooty Mold

48. Pine Tortoise Scale and Sooty Mold

49. Striped pine scale and sooty mold

50. Hemiptera The Armored Scales: covered with a hard wax or protective coating