Southern Chinch Bug Management
Transcription
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: [email protected] 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 1 5/23/2012 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) 2 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 3 5/23/2012 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 5 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) 6 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 7 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 [email protected] 8