scales found in walnut: identification, life cycles ... · scales found in walnut: identification,...
TRANSCRIPT
![Page 1: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/1.jpg)
Scales found in Walnut: Identification, Life Cycles, & Management Timing
Dani Lightle UCCE Farm Advisor, Glenn, Butte & Tehama Cos. February 6, 2015
![Page 2: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/2.jpg)
Botryosphaeria lesions under walnut scale
Scale populations are increasing
Photos: T. Michailides
![Page 3: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/3.jpg)
Outline:
1. Scale species common in walnut
2. Scale lifecycles
3. Management timings and options
![Page 4: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/4.jpg)
Most common scale species: walnut scale
Daisy-like scalloped margins
![Page 5: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/5.jpg)
Most common scale species: walnut scale
Tree symptoms with high populations: • Branch dieback • Splitting bark • May appear water stressed
![Page 6: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/6.jpg)
Frequently encountered scale species:
European fruit lecanium Frosted scale
Rounded, army-helmet shape
![Page 7: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/7.jpg)
European fruit lecanium versus frosted scale:
Identical most of the year White waxy coating on Frosted scale only during March-April
![Page 8: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/8.jpg)
Lesser common scale species:
San Jose Scale Circular with raised ‘nipple’
![Page 9: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/9.jpg)
Lesser common scale species:
Italian Pear Scale
San Jose Scale Circular with raised ‘nipple’
Associated with Lichens
![Page 10: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/10.jpg)
Generic scale lifecycle: eggs
abundantnature.com
![Page 11: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/11.jpg)
Generic scale lifecycle
Unhatched eggs
![Page 12: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/12.jpg)
Generic scale lifecycle
Eggshells
![Page 13: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/13.jpg)
Generic scale lifecycle
Crawlers
![Page 14: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/14.jpg)
Generic scale lifecycle: crawlers
Adult spider mite
Scale crawler
![Page 15: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/15.jpg)
Generic scale lifecycle: nymph development
Lose: ‒ Legs ‒ Eyes ‒ Antennae
Gain: + Scale cover + Rudimentary eye
spots (if male)
![Page 16: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/16.jpg)
Generic scale lifecycle: females versus males
Female: no eye spots, legs, or antennae Male: eye spots, penile sheath
![Page 17: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/17.jpg)
Generic scale lifecycle: females versus males
Adult male: Winged, flies to females
![Page 18: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/18.jpg)
Walnut Scale Lifecycle
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Walnut Scale Males
Crawlers
Males
Crawlers
Development Nymph
Development 2nd instar
• 2 generations per year • Overwinter as 2nd instar nymph
Adult females
![Page 19: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/19.jpg)
Frosted Scale / European Fruit Lecanium Lifecycle
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Eggs
Rapid
growth
into
adults Frosted Scale
2nd instar 2nd instar
1st instar rs Crawlers Crawlers
• 1 generation per year
![Page 20: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/20.jpg)
Frosted Scale / European Fruit Lecanium Lifecycle
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Eggs
Rapid
growth
into
adults Frosted Scale
2nd instar 2nd instar
1st instar rs Crawlers Crawlers
• 1 generation per year • Overwinter as 2nd instar nymph
![Page 21: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/21.jpg)
Managing scale: in-season monitoring
Have monitoring tapes out by early May
Double-sided tape
![Page 22: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/22.jpg)
Check regularly with a hand lens
Managing scale: in-season monitoring
Scale tape under more powerful magnification
Often high densities at margins of tape
![Page 23: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/23.jpg)
Scale Monitoring: Red Bluff 2014 – Walnut Scale
0
10
20
30
40
50
60 A
vg. #
of
Cra
wle
rs /
Day
Average Number of Crawlers per Day
![Page 24: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/24.jpg)
Scale Monitoring: Red Bluff 2014 – Walnut Scale
0
10
20
30
40
50
60 A
vg. #
of
Cra
wle
rs /
Day
Average Number of Crawlers per Day
![Page 25: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/25.jpg)
0
10
20
30
40
50
60 A
vg. #
of
Cra
wle
rs /
Day
Average Number of Crawlers per Day
Aug. 23rd Assail, 8oz/ac
Scale Monitoring: Red Bluff 2014 – Walnut Scale
![Page 26: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/26.jpg)
0
10
20
30
40
50
60 A
vg. #
of
Cra
wle
rs /
Day
Average Number of Crawlers per Day
Aug. 23rd Assail, 8oz/ ac
Sep. 22nd Harvest
Scale Monitoring: Red Bluff 2014 – Walnut Scale
![Page 27: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/27.jpg)
0
1
2
3
4
5
6
7
8
Avg
. # o
f C
raw
lers
/ D
ay
Average Number of Crawlers per Day
Aug. 23rd Assail, 8oz/ ac
Sep. 22nd Harvest
Scale Monitoring: Red Bluff 2014 – Frosted Scale
![Page 28: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/28.jpg)
Managing scale: treatment timings & options
Timings: Delayed dormant (bud swell until flowering) Crawler stage - research suggests may be more effective timing
![Page 29: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/29.jpg)
Managing scale: treatment timings & options
Timings: Delayed dormant (bud swell until flowering) Crawler stage - research suggests may be more effective timing
Organic treatment options: Organic option: oils -Don’t apply when dormant! Narrow range oils during summer: -Watch for phytotoxicity
![Page 30: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/30.jpg)
Managing scale: Current Research into Control Options Lead researchers: B. Van Steenwyk, C. Wise, J. Hasey
Methods: • 4 replicates in Vina walnuts • Each tree monitored with sticky tape -- March 25th – June 2nd - First crawlers: April 23rd • Treatments applied:
- Post Delayed Dormant – April 8 - Crawler stage: May 6
![Page 31: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/31.jpg)
Study treatments
Treatments: Post Delayed Dormant (April 8): Centaur 70 WDG Seize 35 WP Crawler Stage (May 6): Movento 2SC Assail 30SG Assail 30SG Brigadier 2EC Closer 2SC Centaur 70 WDG Untreated check
Rate Form/ ac: 46.0 oz 5.0 oz 9.0 fl. oz 9.6 oz 5.3 oz 12.8 fl. oz 5.75 fl. oz 46.0 oz ---
![Page 32: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/32.jpg)
Results: Mean Crawlers / Day: May 12 – June 2, 2014
0
5
10
15
20
25
Untreated check
Centaur 70 WDG
(delayed dormant)
Seize 35WP (delayed dormant)
Assail 30SG Assail 30SG Movento 2SC
Brigadier 2EC
Closer 2SC Centaur 70 WDG
Mea
n c
raw
lers
/ cm
/ d
ay a a
a
bc
c
b
(5.3 oz/ac) (9.6 oz/ac)
a
d
bc
![Page 33: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/33.jpg)
0
1
2
3
4
Untreated check
Centaur 70 WDG
(delayed dormant)
Seize 35WP (delayed dormant)
Assail 30SG Assail 30SG Movento 2SC
Brigadier 2EC
Closer 2SC Centaur 70 WDG
# liv
e sc
ale
/ cm
ab
c c
bc
c
a
bc
c c
Results: Live Scale / cm: Jan 21, 2015
(5.3 oz/ac) (9.6 oz/ac)
![Page 35: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/35.jpg)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Eggs
Rapid growth
into adults
Walnut Scale
Frosted Scale
Males
Crawlers
Males
Crawlers
Nymph development
2nd instar
Nymph Development 2nd instar
2nd instar
1st instar Crawlers Crawlers
![Page 36: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/36.jpg)
0
10
20
30
40
50
60
Avg
. # o
f C
raw
lers
/
Day
Aug. 23rd Assail, 8oz/ ac
Sep. 22nd Harvest
Scale Monitoring: Red Bluff 2014 – Walnut Scale
![Page 37: Scales found in Walnut: Identification, Life Cycles ... · Scales found in Walnut: Identification, Life Cycles, & Management Timing Dani Lightle UCCE Farm Advisor, Glenn, Butte &](https://reader033.vdocuments.us/reader033/viewer/2022050517/5fa138904f9e0a452f3f9702/html5/thumbnails/37.jpg)
0
2
4
6
8
Avg
. # o
f C
raw
lers
/ D
ay
Aug. 23rd Assail, 8oz/ ac
Sep. 22nd Harvest
Scale Monitoring: Red Bluff 2014 – Frosted Scale