General Turf Insects – Stem and Thatch Pests

1. General Turf Insects – Stem and Thatch Pests David J. Shetlar, Ph.D. The “BugDoc” The Ohio State University, OARDC & OSU Extension Columbus, OH © October, 2003, D.J. Shetlar, all rights reserved

2. Stem & Thatch Pests Chewing Pests (feed on stems, clippings & leaves) Cranberry Girdler Crane Flies March Flies (borers of stems & crowns) Billbugs Annual Bluegrass Weevil Frit Fly Sucking Pests Chinch Bugs Spittlebugs Mealybugs Scales

3. Cranberry Girdler (=subterranean sod webworm) Chrysoteuchia topiaria (Zeller) Notes: This pest is technically a crambid type sod webworm, but it has a very different larval behavior. The larvae tend to feed on the stems and crowns of turf, when large, rather than feeding on leaves. Infested turf tends to die in irregular patches, often at the time that white grubs would be causing similar damage. In thick turf, the dead canopy can be pulled back to reveal considerable amounts of straw colored frass pellets on the soil/thatch surface. With grubs, the entire turf canopy with the thatch can be pulled back to reveal grubs in the soil/thatch interface.

4. Cranberry girdler adults are small crambids with distinctive bands of silver scales along the wing tip. The adults tend to fly from late June through much of July. There is only one generation per year. Cranberry girdler larvae have the typical sclerotized plates that all sod webworms have, but the plates are the same color as the rest of the integument. Therefore, the typical spots are not apparent!

5. Cranberry Girdler Distribution Cranberry girdler most commonly reaches pest status in the northern part of this range. It is also a common pest in the Canadian Provinces. Damage is a perennial occurrence in Utah, Washington, Oregon, Wisconsin and Minnesota.

6. Crane Flies (=leatherjackets) European Crane Fly, Tipula paludosa (Meigen) European Marsh Crane Fly, Tipula oleracea L. Native Crane Flies, Tipula & Pedicia spp. Notes: The European and European marsh crane flies are imported pests that are well established in British Columbia, Washington and Oregon. Recent reports indicate that either or both species are also in the eastern Canadian Provinces and perhaps bordering states. Native species of crane flies can also be found infesting turf, especially turf that has been damage from snow mold or overly wet soils. The larvae are often called leatherjackets because of their tough exoskeletons, and the adults are called daddy-long-legs in Europe.

7. Adult crane flies tend to emerge in the fall or spring, depending on the species. The European crane fly emerges in September and October. The large mosquito-shaped flies often scare people, but they have non- functioning mouthparts. Eggs are usually oval and shiny black. The larvae feed on grass blades, clippings and thatch. Most crane fly larvae have gray to brown bodies with conspicuous caudal projections and a black to dark brown head capsule. Both the caudal projections and head can be withdrawn into the body when the larvae are disturbed.

8. Stem Borers Billbugs Annual Bluegrass Weevil Frit Fly

9. Billbugs Bluegrass Billbug,Sphenophorus parvulus Hunting Billbug,S. venatus vestitus Phoenician (=Phoenix) Billbug, S. phoeniciensis Chittenden Rocky Mountain (=Denver) Billbug, S. cicatristriatus Fahraeus

10. Blugrass billbug adult Hunting billbug adult Phoenician billbug adult Denver billbug adult

11. Billbug Distribution Maps Bluegrass billbug Hunting billbug Phoenician billbug Denver billbug

12. Billbug damage to lawn © HDN Bluegrass billbug adult on sidewalk © HDN

13. Bluegrass Billbug Adult and larva Larva in crown, note frass filled stem.

14. The “Tug Test” To detect and confirm bluegrass billbug activity, grasp suspect stems and tug lightly. If billbug larvae have been feeding, damaged stems will break off easily. Inspect the broken stems for sawdust like frass.

15. Bluegrass Billbug Life Stages © HDN small larva mature larva fresh pupa mature pupa callow adult mature adult Most believe that billbugs have five to six larval instars. The first two or three instars are usually small enough to burrow within stems, but eventually they have to chew their way out and feed externally on crows, stems and rhizomes. When ready to pupate, the mature larva burrows into the soil and forms a compact pupal cell. The pupa is first cream colored and gradually turns a reddish brown at maturity. Newly emerged adults often have this brown color and they are called “callow adults.” Eventually, the adults turn blackish gray.

16. Bluegrass Billbug Life Cycle in Ohio

17. Notes: Bluegrass billbugs overwinter in the adult stage. The adults may hide in taller grasses nearby the turf, along sidewalks, stone walls and building foundations. Adults have also been found in thatch and old worm holes. When the soil surface temperature reaches 68ºF, the adults become active – seeking grass stems on which to feed, mating and laying eggs. Most females have mated the previous fall, but they can mate again in the spring. Females seek the thickest stems, often the seed stem, in which to excavate a hole and insert a bean shaped egg. The eggs hatch in a week or more and the small larvae burrow up and then down the stems, leaving the stems filled with sawdust like frass. By the third instar, most larvae are too large to remain within the stems. They then feed in the larger crowns or externally on the crowns, roots and rhizomes. Adults lay eggs over a long period of time. Larvae mature from mid-June to early July at which time they dig deeper into the soil to pupate. The pupal stage takes about two weeks to complete and new adults are commonly found in mid-July into August. Occasionally, summer adults will lay eggs for a partial second generation. Any larvae or pupae that haven’t finished development by the time of the first freeze appear to die. The adults are commonly seen walking about on sidewalks and driveways in September and October. Billbug control with pesticides uses one of two tactics – adult elimination before egg lay and/or larval control. Surface insecticides applied in early May usually eliminate sufficient adults to prevent damage. Larval control insecticides should be applied from mid-May into early June. Billbugs can also be easily controlled by using endophytic grasses.

18. 1999 Ohio Billbug Curative Treatment Rate % Control 87.5 4.00 Scotts 3.2% diazinon on 28-4-6 4.36 68.8 VIGRO 3.34% diazinon on 28-4-6 Ortho Diazinon (5%G) 4.36 58.3 Ortho Dursban (1%G) 0.87 16.7 0.10 20.8 0.2%G Bifenthrin Intercept H&G (0.1% deltamethrin) 0.13 16.7 Spectricide 3X (0.25 permethrin) 0.27 45.8 MACH2 2LTI 1.50 20.8 appl - 11 Jun; Wooster, OH; read - 30 Jun(19DAT); 24.4 BBs/sq.ft. check

19. 1999 Ohio Billbug Preventive Treatment Rate Date Appl % Control 7 May 67 DeltaGard 0.4SC 0.13 Merit 75WP 0.40 7 May 96 Scimitar 0.88GC 0.06 7 May 81 MACH2 2LTI 1.50 7 May 81 MACH2 2LTI 1.50 11 Jun 89 0.26 7 May 100 Meridian 25W 0.20 11 Jun 81 Meridian 25W appl - 6May; Columbus, OH; read - 25June(48DAT); 32.0 adults/sq.ft. check

20. 2000 Ohio Billbug Preventive Test Treatment Rate % Control Diazinon 3.34G 4.36 92 Diazinon 3.2G 4.0 95 Talstar PL 0.2G 69 0.1 Talstar Fert 0.2G 72 0.1 Tempo 0.1G 0.13 67 appl - 16 May; Wooster, OH; read - 5July; 24.7 larvae/sq.ft. check

21. Talstar 0.147G 0.2 64 Talstar 0.086G 0.1 43 Tempo 0.1G 50 0.087 Permethrin 0.25G Merit 0.5G 32 86 0.4 0.272 MACH2 1.5G Diazinon 3.2G 4.0 1.5 36 68 2001 Ohio Billbug Preventive Test Treatment Rate % Control appl - 24 May (late preventive); Wooster, OH; read - 12July; 17.8 larvae/sq.ft. check

22. Annual Bluegrass Weevil Listronotus (=Hyperodes) maculicollis This weevil was included in the genus Hyperodes for many years and many still refer to this pest as the “Hyperodes weevil.”

23. Annual Bluegrass Weevil Distribution

24. Annual bluegrass weevil (left to right): adult, pupa, annual bluegrass stem, larva. H. D. Niemczyk

25. Notes: The annual bluegrass weevil is so named because it attacks annual bluegrass, Poa annua. This pest is found in northeastern North America, including most of the New England States and eastern Canadian Provinces. Its damage is most evident where Poa annua is intensively managed (e.g., golf course greens and tees, lawn bowling ranges, and lawn tennis courts). In the past, it was stated that this pest exclusively feeds on P. annua, but recent investigations indicate that the larvae will also damage bentgrass, especially when bentgrass is mixed with the P. annua. The adult weevils feed on the margins of grass leaves, causing a ragged appearance and general thinning of the turf cover. This can often be mistaken for disease. Adults overwinter in leaf litter, especially pine needle duff, surrounding managed turf. In early spring, when Forsythia first blooms to the time that flowering dogwood begins to bloom, the adults move back into the turf to feed and begin laying eggs. Females insert small bean shaped eggs into leaf sheaths and the typical weevil larvae burrow into the stems. The larvae move down to the crown and can entirely consume the crown and surrounding tillers. By early June, the first generation is completed and new adults can be seen by mid to late June. Over most of its range, a second generation is completed. The first generation is usually the most damaging one, but if there is a cool, moist summer, the second generation can cause significant damage also.

26. Annual bluegrass weevils commonly kill Poa annua at the time that it may normally die (the true annual forms) or go into summer dormancy. H. D. Niemczyk

27. Early damage from annual bluegrass weevils can look like disease or other malady. H. D. Niemczyk

28. Close up of annual bluegrass weevil damage to Poa annua on green. H. D. Niemczyk

29. Annual bluegrass weevil larvae feed at the crown, causing the top portion of the plants to die. H. Tashiro

30. Annual Bluegrass Weevil in NY Redrawn from P. Vittum & H. Tashiro, 1987 data

31. Annual Bluegrass Weevil in NY (with control windows) Adult Control Curative Control Severe Damage Redrawn from P. Vittum & H. Tashiro, 1987 data

32. Adulticide controls are usually applied from the time that Forsythia is in full bloom to the time that flowering dogwood begins to bloom. This technique uses a technique called phenological indicators – coordination of pest activity with visual cues given by various plants. Using these phenological indicators only works for the first generation. Second generation adults and larval populations have to be monitored using visual inspections of the turf.

33. ABG Weevil Management • Sampling (watch for adult weevils when forsythia is in bloom) • Keep Records (which tees & greens get hit and damaged?) • Preventive Applications (recommended – Dursban or pyrethroid when adults move) • Curative Applications (not very effective)

34. rate ave Insecticide lb.ai . /a. % control # tests Carbaryl 8.0 55.6 2 (= Sevin) Chlorpyrifos 1.0 53.6 7 (=Dursban) 2.0 73.3 32 Isofenphos 2.0 51.2 7 (=Oftanol) Bendiocarb 2.0 28.6 13 (=Turcam) 3.0 78.4 5 Trichlorfon 8.0 33.5 7 (=Dylox, Proxol) Ranked Efficacy of ABGW Insecticides (used as preventives) - 1989 – 2000a OPs & Carb a Data from ESA publications (1989-2000) using annual bluegrass weevil data where timing of application was stated to be “preventive.”

35. rate ave Insecticide lb.ai . /a. % control # tests Bifenthrin 0.05 88.2 12 (=Talstar) 0.1 95.5 24 Cyfluthrin 0.14 87.6 15 (=Tempo) Deltamethrin 0.06 62.0 6 (=DeltaGard) 0.13 90.0 11 lam-Cyhalothrin 0.03 92.8 8 (=Scimitar) 0.06 97.3 8 Ranked Efficacy of ABGW Insecticides (used as preventives) - 1989 – 2000a Pyrethroids a Data from ESA publications (1989-2000) using annual bluegrass weevil data where timing of application was stated to be “preventive.”

36. rate ave Insecticide lb.ai . /a. % control # tests Halofenozide 1.5 48.5 10 (=MACH2) 2.0 41.1 8 Imidacloprid 0.3 39.7 23 (= Merit) 0.4 59.7 7 Imidacloprid + 0.3 Cyfluthrin 0.14 87.4 12 Thiamethoxam 0.2 (= Meridian) 0.26 Ranked Efficacy of ABGW Insecticides (used as preventives) - 1989 – 2000a NeoNs & IGR a Data from ESA publications (1989-2000) using annual bluegrass weevil data where timing of application was stated to be “preventive.”

37. Frit Fly Adult frit flies are commonly attracted to light colored surfaces like golf balls, caps, tee markers, etc. Close up of the frit fly on a grass blade.

38. Notes: There are several species of flies in the family Chloropidae that have larvae that burrow into the stems of grasses and small grain crops. This often damages the seed stems, causing the developing seeds to wither. These withered seeds are called frits, which is where the name frit fly comes from. The true frit fly, Oscinella frit (Linnaeus), is a native of Europe, but it has been spread around the world. Other chloropids may also be infesting turf. Young frit fly larvae overwinter within a grass stem. In the spring, the larvae continue to burrow down the stem, killing everything outward from where they are feeding. The affected stems first turn yellow and then brown. Up to four generation can occur during a season, and adults are most common in mid-May, late June, late July and mid-September, in Ohio. The adult flies are attracted to light colored surfaces and often alight on golf balls, thereby causing the golfer to lose concentration. Damage is often misdiagnosed as disease or drought problems. Only careful inspection of stems that are turning yellow will reveal whether the malady is being caused by frit fly maggots or some other reason.

39. Chinch Bugs Hairy CB, Blissus leucopterus hirtus Common CB, B. l. leucopterus Southern CB, B. insularis Buffalograss CB, B. occidus

40. Hairy chinch bug adults - long wing & short wing forms Hairy chinch bugs in thatch

41. Hairy Chinch Bug Damage to Lawn

42. Hairy chinch bug Common chinch bug Chinch Bug Distribution Maps Southern chinch bug

43. Hairy Chinch Bug Life Stages egg 1st 2nd 3rd 4th 5th normal winged short winged instar nymphs adult adult

44. Hairy Chinch Bug Life Cycle in Ohio

46. Notes: The hairy, common and buffalograss chinch bugs appear to overwinter as adults. In the spring, the adults seek out suitable places to feed and lay eggs. For the hairy chinch bug, most of May is spent laying eggs and the nymphs develop from late May into early July. The later instar nymphs cause severe damage by clogging up the vascular bundles within stems and even at the crown. Damaged crowns often die. Chinch bug populations are highly regulated by rainfall and moisture. The small nymphs are susceptible to drowning in saturated thatch and all stages appear to be susceptible to the white fungus of insects, Beauveria. In normal years, a second generation is produced in late July through August. Occasionally, this second generation can be larger than the first with significant turf damage appearing in late August to mid-September. In Canada, the hairy chinch bug completes only one generation with damage being most evident in July and August. Where turf is at risk of chinch bug damage (e.g., previous experience indicates that chinch bug damage is a regular occurrence), applying controls to eliminate overwintered adults is a useful strategy. Otherwise, if visual inspection in early to mid-June and again in August reveals numerous chinch bugs and early signs of damage, curative insecticide applications are in order. Chinch bugs are rarely a problem in regularly irrigated turf or in turf containing endophytes.

47. Hairy chinch bug life cycle in Ohio with damage and control windows

48. Merit 75WP 0.3 92 96 Exp NN 0.3 90 87 Exp NN 0.4 78 81 Tempo Ultra 0.1 83 63 Tempo 20WP 0.2 22 0 Talstar SC 0.1 98 98 2001 Ohio Hairy Chinch Bug Control % Control Treatment Rate 7DAT 14DAT appl. 30 Aug., Springboro, OH; 943.5 & 418.6 hcb/sq.ft. checks @ 7, & 14 DAT

49. Southern chinch bugs often damage St. Augustine grass, but they can also infest bermudagrass and zoysia. In the midwestern states, the buffalograss chinch bug seems to be the most common species attacking zoysia. To the untrained eye, southern chinch bug damage often appears to be drought stress or improper irrigation distribution. The only way to tell is to look in the thatch for chinch bug nymphs and adults.

50. % Control Treatment 6DAT Rate Talstar PL 0.2G 99 0.10 “ 100 0.26 69 DeltaGard 0.1G 0.09 “ 86 0.13 Dursban 1G 86 1.00 Meridian 0.33G 98 0.20 2000 FL Southern Chinch Bug Control appl. 7 Sep., Boca Raton, FL; 515.1 scb/sq.ft. checks @ 6 DAT; St. Augustinegrass