Phoenician billbugSphenophorus phoeniciensis

Bermudagrass fairwaySymptoms first appear during spring greenup

Billbug damage to kikuyugrass

Damage on stems and stolons

kikuyugrass

kikuyugrass

kikuyugrass

Phoenician billbugs in California

• Causing more damage than previously thought on kikuyu and bermudagrass fairways, sod

• 1st Symptoms during spring green-up, in stressed areas

• Multiple generations: year-round?

• Symptoms mimic dollar spot, spring dead spot, delayed green-up, drought stress

TriggerLas

VegasBakers-

fieldSan

Diego

Billbugs Greenup 4/1 4/15 6/1

BTA 2-4 wks after 65F

5/1-5/15 5/15-5/30 6/1-6/15

Chafers July 7/1 7/1 7/1

Soil moisture andwhite grub management

Soil moisture sampling: TDR 300 soil moisture meter & Trimble Ag GPS 132

Soil moisture determined in 95 areas that showed signs grub damage

After testing for soil moisture, sampling for grubs occurred

Pasadena masked chafer, Cyclocephala pasadenae

Higher soil moistures favored the presence of chafer grubs

Higher soil moistures favored the presence of chafer grubs

1.6% chaferdamage

Role of irrigation distribution and soil moisture in chafer damage

3 in/hr

4 in/hr

5 in/hr

6 in/hr

Lack of irrigation uniformity is a given

3 in/hr

4 in/hr

5 in/hr

6 in/hr

3 in/hr

4 in/hr

5 in/hr

6 in/hr

3 in/hr

4 in/hr

5 in/hr

6 in/hr

3 in/hr

4 in/hr

5 in/hr

6 in/hr

GrubArea damage

GPS Mapping Data

Precip in/hr

Areasq ft

%Area

Damagesq ft

% damagedarea

3 2,484 33.7 11.0 0.4

4 3,287 44.6 50.8 1.5

5 1,464 19.9 53.8 3.7

6 136 1.8 1.0 0.7

Total 7,371 116.6 1.6

Use maps and sensors to:

• Identify, illustrate, quantify complex problems

• Scout high risk wet areas first– Irrigated by multiple heads– Low spots– Poorly drained spots

• Spot treat with more precision• Track progress• Identify and fix wet areas

The future: passive data acquisition

Equipment:

• Geonics EM38 sensor (soil moisture)

• NTech NDVI sensors (turf quality)

NDVI sensors for turf quality

• LED light sources

• Modulated a high frequencies

• Allows sensors to ignore ambient light

• NIR 770 nmRed 656 nmGreen 525 nm

Soil moisture, Fairway 9

Altitude variations, Fairway 9

Turf quality, Fairway 9

www.paceturf.org

Dealing with year-round grubs

• Split application of Merit (4.3 oz/A), 2 – 3 months apart

• Split application of Allectus (4.5 pint/A) 2 – 3 months apart

• Spring application of Merit at higher rate (6.4 oz/A) followed by a different systemic only if needed

Problem: Allectus, Merit and Mach 2 have yearly application limits