Southern Chinch Bug Management

5/23/2012
Outline…
A. What’s the problem?
p
Southern Chinch Bug Management
B. Which biological, cultural, and chemical factors may have contributed to the problem?
C. What do we know?
Eileen A. Buss, Ph.D.
Associate Professor & Extension Specialist
Entomology & Nematology
UF/IFAS, Gainesville
Office: 352‐273‐3976
Email: eabuss@ufl.edu
D
can we do?
D. What
What can we do?
L. Buss
A. What’s the Problem?
This is all chinch bug damage!
• Southern chinch bug nymphs and adults feed in phloem of St. Augustinegrass leaf sheaths
phloem of St. Augustinegrass
leaf sheaths
• Plant growth declines; grass blades turn yellow then brown; patches of grass die
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All Turf Damage is Not Caused By Bugs
How Do You Know If Bugs are Present?
Vi
l
li
Visual sampling
Scalping damage
Herbicide damage Untreated Edge
Accurate
diagnosis
is critical!
Drought stress
Vacuum sample
Flotation or turf sample
Dog “toilet” area
Insecticide Resistance Track Record
1953: Chlordane ((Wolfenbarger
g 1953))
1957: DDT (Kerr & Robinson 1958)
1960: Parathion (Kerr 1960)
1976: Chlorpyrifos, Diazinon, Trichlorfon
(Reinert & Niemczyk 1982)
1983: Propoxur (Reinert & Portier 1983)
2005: Bifenthrin (Cherry & Nagata 2005)
2007: Deltamethrin, Imidacloprid (Cherry & Nagata 2007)
2011: Permethrin (Vazquez et al. 2011)
Bifenthrin‐‐resistant
Bifenthrin
Deltamethrin‐‐resistant
Deltamethrin
Permethrin‐‐resistant
Permethrin
Imidacloprid‐‐resistant
Imidacloprid
Sanibel Is.
Locations of Locations of Resistant Resistant Southern Chinch Bugs
Southern Chinch Bugs
Cherry & Nagata (2003), Cherry & Nagata (2007), Vazquez et al. (2011, in review)
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5/23/2012
What is the Southern Chinch Bug Doing?
• It is detoxifying the insecticides (metabolic resistance)
• We suspect that these enzymes are involved:
– Cytochrome P450
– Glutathione‐S‐transferase
– Esterase
There is a Cost to Being Resistant
• We’re not sure how to define this, but maintaining resistance is not “easy” for the chinch bugs
• We know this because, in the absence of selection pressure, pyrethroid resistance is lost
• Example: a highly resistant population was put into colony; lost resistance ≤ 8 generations
– Could it be like exercising? As soon as you stop, your metabolism might change?
1. Biological Factors: Southern Chinch Bug
B. WHAT MAY HAVE CONTRIBUTED TO THE PROBLEM?
Lyle Buss, UF/IFAS
• Tiny
Tiny piercing
piercing‐sucking
sucking insect that insect that
attacks St. Augustinegrass
• Active year‐round in S. FL, from Apr to Nov in N. FL.
• Overlapping generations
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How Many & Often Are Eggs Laid?
• A female starts laying eggs ~1 wk after becoming an adult
an adult
• Eggs hatch within 7‐14 d (Kelsheimer &Kerr 1957, Eden &Self 1960)
• 4‐5 eggs are laid singly/female/day for 8‐9 wks
• If 5 eggs/day for 60 days = 300 eggs/female
• Development from egg to adult takes 5‐8 wk (Vázquez et al. 2010).
(Burton and Hutchins 1958, Kerr 1966, Leonard 1966, Sweet 2000). Effect of Migration on Resistance
• Immigration of susceptible individuals into treated areas can slow resistance development by increasing the frequency of
slow resistance development by increasing the frequency of susceptible alleles in a treated population (Comins 1977, Georghiou & Taylor 1977, Curtis et al. 1978, Taylor & Georghiou 1979, Tabashnik & Croft 1982, Roush & Daly 1990, Tabashnik 1990)
• Emigration of resistant individuals from treated areas can also speed the resistance development in the untreated area (Comins
1977, Sutherst & Comins 1979)
Population 1
Population 2
Pure susceptible
No insecticide use
Pure resistant
Frequent insecticide use
How Far Can a Chinch Bug Move?
• Long‐winged
Long winged adults fly on hot days and adults fly on hot days and
overcrowded conditions
• Nymphs and short‐winged adults walk
• If a property = a chinch bug population
– Then encroachment by/interbreeding with a /
neighboring population can either increase or decrease the level of resistance
(Kerr and Kuitert 1955, Kelsheimer and Kerr 1957, Kerr 1966, Reinert and Kerr 1973)
2. Maintenance Factors
• Maintenance practices should be integrated with chemical control in a chinch bug management program a. Proper irrigation practices
b. Proper fertilization
c. Thatch management 4
5/23/2012
2a. Irrigation
2b. Nitrogen (N)
• Drought stress is often misdiagnosed as chinch bug damage
• N content in host plants influences insect survival, development time body size and reproduction (Mattson development time, body size, and reproduction (M tt
• Make sure the irrigation system is working
• Increased N reduces plant resistance to some insects (esp. beetles & moths) (Barbour et al. 1991)
• Southern chinch bug damage seems related to increased ammonium nitrate use (Horn and Pritchett 1962, Busey and Snyder 1993)
• Makes turf more succulent, so insects can more easily Makes turf more succulent so insects can more easily
pierce the plants
• More N  more southern chinch bug eggs
– Stressed turfgrass may not tolerate a pest damage
– If post‐treatment irrigation is needed, but not available, then consider increasing the spray volume or using a granular
2c. Thatch
• Thatch provides dark, humid habitat for some pests
Th t h
id d k h id h bit t f
t
• It reduces the penetration of pesticides, so more spray volume is needed
• Some pesticides bind with the organic matter, making them unavailable to control the target pests
g
g p
1980, McNeill & Southwood 1978)
2d. Soil pH
• L
Length
th off pesticide
ti id residuals
id l may b
be
affected by soil pH
• Some pesticides may lose effectiveness
when mixed with alkaline water
• Especially true for OPs and Carbamates
• pH may need to be corrected using
acidifiers or buffering agents
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5/23/2012
3. Chemical Factors
• The more often you treat a site, the stronger the resistance is to bifenthrin at that site.
– Georghiou 1986, Rosenheim and Hoy 1986, Croft et al. 1989, He et al. 2007, Magana et al. 2007)
Getting the Best Chemical Control
C. What Can We Do Now?
• Reduce the selection pressure (# of applications) on the pest.
Possible Rotation Products
• Pyrethroids (Group 3)
• Properly calibrate and maintain equipment
• Rotate insecticides with different modes of action
• Use enough spray volume to penetrate thatch
• Add an adjuvant to improve coverage, if needed
• Don’t spray if rain could wash product off or if
wind is gusting too much
– Bifenthrin (Talstar/Onyx), Beta‐cyfluthrin
(Talstar/Onyx) Beta‐cyfluthrin (Tempo), (Tempo)
Deltamethrin (DeltaGard), lambda‐cyhalothrin (Scimitar)…
• Carbamates and Organophosphates (Groups 1 A and B)
– Carbaryl (Sevin) and trichlorfon (Dylox)
• Neonicotinoids (Group 4A)
– Clothianidin (Arena), thiamethoxam (Meridian), imidacloprid (Merit)
• Premix products
– Bifenthrin + imidacloprid (Allectus)
– Bifenthrin + clothianidin (Aloft)
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5/23/2012
We Need to Conserve Current Products
•M
Manufacturing development of new f t i d l
t f
insecticides has slowed – there are no great chinch bug products on the near horizon • Need a rotation partner to conserve the neonics
• Avoiding constant chinch bug exposure to pyrethroids
th id should
h ld restore their usefulness t
th i
f l
Possible Control Program
• Apply
Apply a neonicotinoid
a neonicotinoid in the spring, followed in the spring followed
by a pyrethroid spot treatment in summer • Avoid doing >2 pyrethroid applications per year
• Do
Do NOT add a NOT add a “little
little bit
bit” of bifenthrin
of bifenthrin to a to a
fertilizer application, just because the insecticide is cheap How Do the Neonics Work?
• Effective against both pyrethroid susceptible and pyrethroid resistant chinch bugs. • Stops chinch bug feeding (starting within 24 hrs), but affected chinch bugs may live and walk around for several days after application
– New users often assume that failure to see quick knockdown = lack of control. Not true. • If you stop chinch bug feeding, you stop chinch bug damage Consider a Spring Neonic Treatment
• Advantages:
Advantages: – If control failures occurred the previous fall, rotation is essential
– Knocks back any growing chinch bug populations and prevents turf damage
– Best timing for grub control • Should slow the buildup of ant populations
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5/23/2012
Other Considerations…
D. Potter, UKY
Go Gators!!
• Check your application techniques and make
improvements, if needed
• Educate your clients so they don’t add more
pesticide to their yards
• Consider additional training
– ID cardholders: “Basics of Turfgrass Pest
Management” program through county Extension
– Landscape Pest Management certificate or nonthesis masters programs in Entomology
– Take the “Turf and Ornamental Entomology” online
course (fall or spring semesters)
Eileen Buss
Entomology & Nematology Dept.
352352
-273
273-3976
eabuss@ufl.edu
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