November 1 , 2007

1. Hunting Billbug Damage
2. Newly Revised: 2008 Turfgrass Weed Control for Professionals

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November 1, 2007

1. Hunting Billbug Damage

I recently took a trip to a golf course in Arkansas to help diagnose some damage to Meyer zoysiagrass fairways.
The damage was not evident until a recent dry spell in which it appeared quickly (A). Further inspection of the soil and the turf revealed a couple of things. First, the turf easily pulled up when tugged. Second, small legless larvae were present in the soil. These legless larvae are characteristic of billbugs. A closer inspection of the turf revealed characteristic feeding patterns of billbug larva at the base of the zoysiagrass stems (B). Both billbug adults (C and D) and larva (D) are small and often go unnoticed. Damage to this golf course fairway was likely caused by hunting billbug which is a common best in bermudagrass and zoysiagrass.

Hunting Billbug 

Billbug adults chew holes into the base of the stem where they insert their eggs. The eggs hatch inside the stem and begin to feed around the base of the stem and ultimately enter the soil. Different than the bluegrass billbug, hunting billbugs often overwinter as larva and they feed on the turf even after winter dormancy. Symptoms of damage can occur in the fall or spring. Billbug damage is typically found in sunny, warm areas. Symptoms in bermudagrass and zoysiagrass may appear similar to damage from many other pests and environmental stress (i.e. drought). In bermudagrass damage can also appear similar to spring dead spot. Finding billbug larva and damage from feeding is the only true way to diagnose this pest.

Research by Brent Young and Dr. Jerry Musick, University of Arkansas, tracked the activity of hunting billbugs in Arkansas and found that adult activity was greatest in late March and April, but that there was some level of activity over the entire year. They also found that female adults lay the majority of their eggs (ovarian maturity) anytime between April and October.

Control strategies for the hunting billbug include cultural and chemical. Cultural control in zoysiagrass can be accomplished through good cultivar selection. Dr. James Reinert, Texas A&M University, recently researched hunting billbug tolerance among zoysiagrass cultivars. His data shows that Z. matrella cultivars have a higher level of resistance as a group compared to Z. japonica cultivars. He ranks hunting billbug susceptibility of the cultivars available in Arkansas as follows:

Z. matrella
Zorro - Resistant
Royal - Resistant
Cavalier - Moderately Resistant  
Diamond - Moderately Resistant  

Z. japonica
Crowne - Susceptible     
Palisades - Susceptible     
El Toro - Susceptible     
Meyer - Most Susceptible

Chemical control of the larvae can be achieved preventatively by applications of imidacloprid (Merit), imidacloprid + bifenthrin (Allectus), halofenozide (Mach2), thiamethoxam Meridian), or clothianidin (Arena) in May or June. Applications of pyrethroids (Tempo, Talstar, DeltaGuard, Scimitar, Battle, and others) or chlorpyrifos (Dursban) can be used in April or May to control adults. An application of imidacloprid + bifenthrin (Allectus) can be used in May to control adults present and preventing damage from eggs already laid. Curative applications of carbaryl (Sevin) can be used once damage is found. Follow label instructions.

For a complete list of products see MP144 Insecticide Recommendations for Arkansas

References:
Musick, J. 2007. Personal communication.
Reinert, J. 2007. Personal communication.
Shetlar, D. 2003. Good billbug hunting. Golf Course Management 71(4):107-112.

Aaron Patton

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2. Newly Revised: 2008 Turfgrass Weed Control for Professionals


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