general turf insects – stem and thatch pests david j. shetlar, ph.d. the “bugdoc” the ohio...
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General Turf Insects – Stem and Thatch Pests
David J. Shetlar, Ph.D. The “BugDoc”
The Ohio State University, OARDC & OSU Extension Columbus, OH
John RoyalsCPCC
Chewing Pests
Cranberry Gridler Crane Flies March Flies
Sucking Pests
Chinch Bugs Spittlebugs Mealybugs Scales
Stem & Thatch Pests
Chinch Bugs
Hairy CB Blissus leucopterus hirtus
Common CB B. l. leucopterus
Southern CB B. insularis
Buffalograss CB B. occidus
Hairy Chinch Bug Damage to Lawn
Hairy chinch bugs in thatch
Hairy chinch bug adults - long wing & short wing forms
Chinch Bug Distribution Maps
Hairy chinch bug Common chinch bug
Hairy Chinch Bug Life Stages
© HDN
egg 1st 2nd 3rd 4th 5th short winged normal winged instar nymphs adult adult
Chinch Bugs
• All similar in appearance; adults black with white, ca. 3 mm in length; each folded-back wing has a black spot on costal margin with conspicuous Y extending towards head
• Brachypterous adults predominate• Nymphs first two instars bright red with white
band on anterior abdomen• Orange in third instar (wing pads appear)• Brown in fourth instar (wings to abdomen region)• Black in fifth instar (wings to abdomen region)
Chinch Bugs
• Damage from sucking on plant juices from crown and stems
• Aggregations of chinch bugs cause localized injury which slowly coalesces to larger patches
• Symptoms include yellowing dwarfing, browning, death
• Prefer sunny locations and sandy soils
Hairy Chinch Bug
• Adults over winter in thatch, tall grasses near edges and plant debris;
• In spring adults crawl or fly to host plants, feed and mate
• Females lay eggs in leaf sheaths and crown areas
• Nymphs found by mid-summer, adults in late summer
• Only adults can survive over wintering• One or two generations per year
Southern Chinch Bug
• Adults over winter in thatch, tall grasses near edges and plant debris;
• In early spring adults crawl or fly to host plants, feed and mate
• Female lays eggs in crevices of grass nodes and at junction of stems and blades
• Four or seven generations per year
Billbugs Annual Bluegrass Weevil Frit Fly
Stem Borers
Billbugs
Bluegrass Billbug Sphenophorus parvulus Hunting Billbug S. venatus vestitus Phoenician (=Phoenix) Billbug
S. phoeniciensis Chittenden Rocky Mountain (=Denver) Billbug
S. cicatristriatus Fahraeus
Billbug Distribution Maps
Bluegrass billbug Hunting billbug
Billbug damage to lawn
© HDN
Bluegrass billbug adult on sidewalk© HDN
Bluegrass Billbug
Adult and larva
Larva in crown
The “Tug Test”
© HDN
Bluegrass Billbug Life Stages
small larva mature larva fresh pupa mature pupa callow adult mature adult
BillBugs
• Billbugs are weevils of many species that feed on the crowns of many grasses and grass crops
• Bluegrass Billbug
• Hunting Billbug
Bluegrass Billbug
• Pest of home lawns with cool-season grasses, particularly bluegrass
Hunting Billbug
• Pest of warm-season grasses in the southeast, particularly zoysia and bermuda
• Whereas turf damaged by white grubs may be spongy underneath, turf damaged by billbugs is firm underneath
• In spring, adult bullbugs come out of their over wintering sites (ditch banks, litter, etc)
• Adults feed on the grass stems by chewing into the center of the stems
Hunting Billbug
• After this period of feeding, females deposit their eggs into the stems
• The young larvae start feeding in the stems, then the crowns
• By the critical period of mid summer, when the grass is under stress, the larvae are in their ultimate third instar where they do the most damage feeding on the crown and roots
• Stems can easily be pulled off by hand with a little tug test
• Frass can often be seen in the area of heavy feeding
Hunting Billbug
• Damage first appears as wilting that does not respond to watering, then spotty brown patches, particularly along paved areas
• In late summer pupation occurs and adults emerge again in the fall before seeking a place to hibernate
• 1- year life cycle
Hunting Billbug
• The best stage to detect the insect is the adult stage during there spring migrations
• Adults can be flushed from the grass with a detergent flush
• You must actively search for larvae in the root/crown areas
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.”
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Annual bluegrass weevil (left to right): adult, pupa, annual bluegrass stem, larva.
Annual Bluegrass Weevil Distribution
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Annual bluegrass weevils commonly kill Poa annua at the time that it may normally die (the true annual forms) or go into summer dormancy.
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Early damage from annual bluegrass weevils can look like disease or other malady.
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Close up of annual bluegrass weevil damage to Poa annua on green.
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Annual bluegrass weevil larvae feed at the crown, causing the top portion of the plants to die.
Two Lined Spittlebug
• Eastern US, mostly warm season grasses and ryegrass
• Spittle masses in grass
• Localized wilting
• Adults are pest of hollies