general turf insects – stem and thatch pests david j. shetlar, ph.d. the “bugdoc” the ohio...

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