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Introduction. Turfgrass value: functional, aesthetic, and economicAll values adversely affected by pestOver 300 million acres of turf in the US81 percent in more than 50 million lawns19 percent in parks, golf courses, athletic fields, cemeteries, sod farms, roadsides, other sitesTurfgrass cultu
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1. Turf Insect Pest
2. Introduction Turfgrass value: functional, aesthetic, and economic
All values adversely affected by pest
Over 300 million acres of turf in the US
81 percent in more than 50 million lawns
19 percent in parks, golf courses, athletic fields, cemeteries, sod farms, roadsides, other sites
Turfgrass culture a 25 plus billion dollar per year industry in the US
3. Introduction 500,000 plus people make their living directly from the establishment and maintenance of turf
25 to 30 million households use pesticides at least once yearly on lawns to control insect pests @ cost > 1 billion dollars
4. Driving Factors in Turfgrass Pest Management Increasing demand for high quality turf
Increasing public concern about potential risks to human health and environment
5. Diagnosis and Sampling of Insect Pests Damage caused by insects can often be confused with diseases, drought, or pesticide injury
Therefore, proper diagnosis is the first step in any successful control program
6. Diagnosis and Sampling of Insect Pests Specific pest identification (start with ‘suspects’)
Sampling (based on suspected causes of damage)
7. Diagnosis Guided by the Use of the Knowledge Regarding Type of damage
Location of habitat
Season of occurrence
Other clues
8. General Indications of Potential or Actual Insect Pest Problems Surface Feeding
Large numbers of birds feeding on turf area
Small moths flying zigzag patterns over the turf surface, especially in late evening
Rapid loss of green color similar to fertilizer burn or drought injury, even though the area is adequately irrigated
Frass at or near the soil surface
9. General Indications of Potential or Actual Insect Pest Problems Subsurface feeding
Loose turf surface indicated by poor footing or excessive traffic injury
Damage to turf by insect feeding mammals (moles, skunks, and raccoons)
Overall thinning of turf
Chlorotic areas/ patches of browning turf
10. Three Major Habitat areas for Insects in Turf Leaves and stems
Thatch
Soil
11. Insect Pest in/on Leaves and Stems Most easily controlled because treatments may be applied directly; timing of application is the most important criterion
Detected by careful examination of stems, leaf sheath and leaves (May require magnification)
Bermudagrass mite
Winter grain mite
Rhodesgrass mealybug
Greenbug
Fruit fly
12. Insect Pest in Thatch Thick thatch (grater than ˝ inch) attracts chinch bugs and others. May impede penetration of pesticides into the soil
Chinch bugs
Sod webworms
Cutworms
Armyworms
Fiery skipper
13. Insect Pest in ThatchDetection Flotation primarily to determine the presence or absence of chinch bugs
Detergent flushes for caterpillars, weevils, mole crickets and other insects
With either of these techniques, it is important to sample at the edges of heavily damaged areas since the highest insect populations are often located here rather than in areas already exhibiting severe damage
14. Insect Pest in the Soil Much more restricted in movement
Mole crickets
Ground pearls
White grubs
Billbugs
European cranefly
Primary sampling by examination of the root zone and the soil and sod
Soap flushes work well for mole crickets
15. Types of Damage Chewing insects most common type among turfgrass insects
They have strong mandibles which bite or sever tissues
Damage symptoms exhibit physical removal of plant tissues
Stripping away of the epidermis of leaves
Notching of leaves and stems
Complete severing of plant parts
16. Types of DamageChewing Insects Cont. Hollowing out of stems and crowns
Pruning of roots
Most chewing insects of turf are immature forms (larvae and nymphs) but a few adults are also included
Common chewing pest: White grubs, armyworms, mole crickets, sod webworms
17. Types of DamageSucking Insects Sucking insects pierce and suck plant tissue with modified mouthparts that form a beak which surrounds needle-like mandibles and maxillae
Salivary secretions (sometimes toxic to the plant) are pumped into the plant to aid in sucking up plant sap and cell contents
Plants injured by this method of feeding generally remain completely intact
18. Types of DamageSucking Insects Cont. The entire plant starts to deteriorate because of the loss of plant sap or in the response to the injection of toxic salivary secretions
Early symptoms: Yellowing, wilting, blasting of leaves, necrosis, followed by browning and death of plant
Both adults and nymphs of piercing sucking insects damage turf
Common insects in this group include chinch bugs, greenbugs, and ground pearls
19. Seasonal Occurrence Differences in seasonal occurrence of insects and damage provides diagnostic clue
Winter: only the winter grain mite causes damage during winter
Spring: European crane fly, mole crickets in warm humid regions, and the single generation scarabaeids may cause damage in the spring
Summer: everything else (for example multiple generations of scarabaeids)
Fall: Mole crickets and white grubs
20. Value of early Detection Early symptoms frequently evident before the actual pest is observed
Damage can progress rapidly when large numbers of insects are present
Some insects easier to control in early stage of development
21. Early Symptoms First symptom of damage caused by leaf and stem-feeding insects is yellowing of leaves in small isolated patches
Root feeders cause a gradual thinning of the turf
Positive attribution of symptoms to a pest requires determination that the pest is present in a damaging stage
Dead or brown turf may no longer be harboring the pest responsible
Proper identification is important for proper treatment and prevention
22. Insect Control Strategies for TurfCultural Control Host plant resistance
The underling susceptibility or suitability or the lack thereof… principle method of control…exhibits constant pressure of each pest generation…immunity is the ultimate level but rarely obtainable…exhibition of various degrees of resistance or susceptibility to best
Endophytes sometimes contribute to resistance
23. Insect Control Strategies for TurfCultural Control Turf Vigor
Vigorous, steadily growing stands can deter permanent turf damage
Rapidly growing rhizomes and stolons quickly fill in small localized dead patches
High nitrogen fertilizer can help recover a generally thinned stand
24. Insect Control Strategies for TurfCultural Control Soil Moisture
In high temperature and moisture stress, two groups of insects, chinch bugs and sod webworms, do most of their damage, with the grass going into dormancy, making damage difficult to detect
When adequate moisture is present, symptoms of damage are easier to detect in the form of yellow leaves and small brown patches
25. Insect Control Strategies for TurfCultural Control Thatch Management
Affects some insects directly (chinch bugs), also affects the efficacy of insecticide applications
Many organic insecticides adsorb to organic matter
Dursban is very readily bound to thatch
Many registered pesticides are broken down readily in UV light, and so they must penetrate quickly to do their job
26. Insect Control Strategies for TurfBiological Control Predators, parasites, and pathogens that attack pest species. Predators include other insects and sometimes vertebrates
Advantages of natural controls include their safety, relative permanence, and relative economy, although all of these don’t apply in all cases
27. Insect Control Strategies for TurfBiological Control Predators
Free-living organisms that consume a prey; relatively non-specific such as:
Ground beetles, spiders, some ants, big-eyed bugs, phytoseiid mites and staphalinids common
28. Insect Control Strategies for TurfBiological Control Parasitoids
Insects that have a parasite-like relationship to their host, resulting in host death, develop inside host; quite host-specific, include a number of Hymenoptera and Diptera
29. Insect Control Strategies for TurfBiological Control Pathogens
Fungi, viruses, and bacterial organisms, with some nematodes and protozoans; host specific, potentially self-sustaining, depend heavily on environmental conditions to work
milky disease (bacterial disease of Japanese beetle grubs)
B. thuringiensis, a commercially used pathogen of lepidoptera and others
Nematodes , commercially inoculated with a bacterial pathogen, used against a number of soil-dwelling turf pests
30. Insect Control Strategies for TurfChemical Controls Pesticides (see current state recommendations)
Important to follow label directions accurately
Adherence to legal requirements may be necessary
Most must be watered in after application