Upload
macadamiasociety
View
933
Download
4
Embed Size (px)
DESCRIPTION
Citation preview
Towards Understanding the Economic Impact
of Thrips in South Africa: Preliminary Findings
Colleen Hepburn¹, Michael Stiller² & Martin Villet¹ ¹Department of Zoology & Entomology, Rhodes University, Grahamstown, South Africa
²Agricultural Research Council - Plant Protection Research Institute, National Collection of
Insects: Biosystematics, Roodeplaat, Pretoria, South Africa 1
Aims and objectives:
• Thrips complex - identify and
assign to guilds (damaging /
predatory / beneficial).
• Phenology of thrips causing
damage.
• Develop practical monitoring
and scouting strategies.
• Ascertain damage to flush,
blossoms, nut-set, small &
mature nuts.
• Determine % premature nut
drop and abscission
attributed to thrips.
2
Aims and objectives:
• Does thrips damage affect pre- and
post-zygotic development of nut?
• Does cosmetic damage (bronzing)
affect photosynthesis and / or
kernel characteristics (size / weight
/ oil content)?
• Are some cultivars more
susceptible to thrips damage?
• Begin working on IPM programme
which is ecologically sound.
• Determine % economic loss of
yield.
• Thrips complex distribution in macadamia-growing areas. Photos: Michael Stiller, ARC-PPRI (2012)
3
Order: Thrips (Thysanoptera)
• 2 suborders – Terebrantia and Tubulifera
• 9 families
• 750 genera
• 8000 extant species (> 5500 described)
50% - feed on fungi
40% - feed on dicotyledonous plants
(i.e. grasses)
9% - predatory or feed on mosses,
gymnosperms or cycads
1% - identified as serious pests
(+ transmission of viruses)
4
Average Thrips Life Cycle
(2½ - 4 days)
(1 - 2 days)
(1 - 3 days)
(Longevity
30 - 45 days
150 - 300
eggs)
(1 - 2 days)
(2 - 4 days)
(Immature stages = max.
15 days)
5
Field work (over 33 weeks) - sampling
protocol
• 13 cultivar sites
• 5 data trees in each
cultivar site (n = 65)
• 20 racemes / growth
points on each tree
sampled weekly
(n = 1300)
In total n = 42900
6
Study sites (13) and variety of cultivars
LOCALITY CULTIVAR AGE TREATED
ARC-ITSC Nelmak D Orchard Nelmak D 8 yrs No
ARC-ITSC Variety Orchard Beaumont 13 Yrs No
ARC-ITSC Variety Orchard Nelmak 2 13 Yrs No
ARC-ITSC Variety Orchard 788 13 Yrs No
ARC-ITSC Variety Orchard A4 13 Yrs No
ARC-ITSC Variety Orchard 816 13 Yrs No
ARC-ITSC Variety Orchard A16 13 Yrs No
ARC Friedenheim Farm Beaumont 6 yrs Yes
Commercial Farm 788 4 yrs Yes
Commercial Farm Nelmak D 6 yrs Yes
Commercial Farm 816 4 yrs Yes
Commercial Farm Beaumont 12 yrs Yes
Commercial Farm Nelmak D 12 yrs Yes 7
20 growth points per tree (i.e. new
flush, blossoms, nut set, small
nuts, mature nuts) sampled weekly
8
Photos representing raceme developmental stages
and abscised nuts for each site were taken weekly
(phenology)
9
During the last 7 weeks of sampling, abscised nuts
with and without thrips damage + 20 random nut
sample from trees were tested for maturity (i.e.
dehusked, dried, cracked & floated)
10
AVERAGE # OF THRIPS COLLECTED FROM DATA TREES AT
ALL 13 SITES OVER THE 33 WEEK PERIOD
0
5
10
15
20
25
30
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
ARC NELMAK D 8YRS
ARC VARIETY ORCHARD BEAUMONT 13YRS
ARC VARIETY ORCHARD NELMAK 2 13YRS
ARC VARIETY ORCHARD 788 13YRS
ARC VARIETY ORCHARD A4 13YRS
ARC VARIETY ORCHARD 816 13YRS
ARC VARIETY ORCHARD A16 13YRS
ARC FRIEDENHEIM BEAUMONT 6YRS
COMMERCIAL FARM 788 4YRS
COMMERCIAL FARM NELMAK D 6YRS
COMMERCIAL FARM 816 4YRS
COMMERCIAL FARM BEAUMONT 12YRS
COMMERCIAL FARM NELMAK D 12YRS
AVERAGE TEMPERATURE (°C)
AV
ER
AG
E #
TH
RIP
S F
RO
M A
LL
SIT
ES
W
EE
KL
Y A
VE
RA
GE
TE
MP
ER
AT
UR
E °C
11 WEEKS
COMMERCIAL FARM SPRAY DATES: BEAUMONT
(12 yrs) & NELMAK D (12 yrs) SITES [N.B. Sprays based on
weekly scouting records]
0
5
10
15
20
25
30
0
50
100
150
200
250
300
COMMERCIAL FARM BEAUMONT 12YRS
COMMERCIAL FARM NELMAK D 12YRS
AVERAGE TEMPERATURE (°C)
AV
ER
AG
E #
TH
RIP
S
Acephate
Cypermethrin
Cypermethrin
Cypermethrin
Cypermethrin
WE
EK
LY
AV
ER
AG
E T
EM
PE
RA
TU
RE
°C
WEEKS 12
Defining thrips damage:
Only green, shiny nuts on
tree and green abscised
nuts as at 11 November
2011
13
Two weeks later (26 November 2011), there
was a change in colour of some of the nuts
14
Abscised nuts: different types of husk damage
15
TOTAL # ABSCISED NUTS OVER 33 WEEK
SAMPLING PERIOD
16
0
5
10
15
20
25
30
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
2400
2600
2800
3000
3200
3400
3600
3800
4000
4200
ARC NEL D 8YRS
ARC VAR ORCH B'MONT 13YRS
ARC VAR ORCH NEL 2 13YRS
ARC VAR ORCH 788 13YRS
ARC VAR ORCH A4 13YRS
ARC VAR ORCH 816 13YRS
ARC VAR ORCH A16 13YRS
ARC F'HEIM B'MONT 6YRS
COMM FARM 788 4YRS
COMM FARM NEL D 6YRS
COMM FARM 816 4YRS
COMM FARM B'MONT 12YRS
COMM FARM NEL D 12YRS
AVERAGE TEMPERATURE (°C)
TO
TA
L #
AB
SC
ISE
D N
UT
S
WE
EK
LY
AV
ER
AG
E T
EM
PE
RA
TU
RE
WEEKS
AVERAGE NUMBER OF ABSCISED NUTS SHOWN BY
STUDY SITE IN DESCENDING ORDER
17
RATING
STUDY SITE
AVERAGE #
ABSCISED
NUTS
1. Commercial Farm Beaumont 12 Yrs 391
2. Commercial Farm Nelmak D 12 Yrs 222
3. Commercial Farm 816 4 Yrs 170
4. ARC Variety Orchard Nelmak 2 13 Yrs 139
5. ARC Variety Orchard A16 13 Yrs 135
6. ARC Variety Orchard A4 13 Yrs 94
7. ARC Variety Orchard 816 13 Yrs 93
8. ARC Nelmak D Orchard 8 Yrs 62
9. ARC Variety Orchard 788 13 Yrs 61
10. Commercial Farm Nelmak D 6 Yrs 54
11. ARC Variety Orchard Beaumont 13 Yrs 53
12. Commercial Farm 788 4 Yrs 44
13. ARC Friedenheim Farm Beaumont 6 Yrs 25
TOTAL # ABSCISED NUTS WITH THRIPS DAMAGE
OVER TIME.
18
0
5
10
15
20
25
30
0
200
400
600
800
1000
1200
ARC NEL D 6YRS
ARC VAR ORCH B'MONT 13YRS
ARC VAR ORCH NEL 2 13YRS
ARC VAR ORCH 788 13YRS
ARC VAR ORCH A4 13YRS
ARC VAR ORCH 816 13YRS
ARC VAR ORCH A16 13YRS
ARC F'HEIM B'MONT 6YRS
COMM FARM 788 4YRS
COMM FARM NEL D 6YRS
COMM FARM 816 4YRS
COMM FARM B'MONT 12YRS
COMM FARM NEL D 12YRS
WEEKLY AVERAGE TEMPERATURE (°C)
TO
TA
L #
NU
TS
WIT
H T
HR
IPS
DA
MA
GE
WEEKS
WE
EK
LY
AV
ER
AG
E T
EM
PE
RA
TU
RE
°C
AVERAGE # ABSCISED NUTS WITH AND WITHOUT
THRIPS DAMAGE – ALL SITES
19
0
5
10
15
20
25
30
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
AVE # ABSCISED NUTS
AVE # ABSCISED NUTS NO THRIPS DAMAGE
AVE # ABSCISED NUTS WITH THRIPS DAMAGE
AVERAGE TEMPERATURE (°C)
AV
ER
AG
E #
AB
SC
ISE
D N
UT
S
WE
EK
LY
AV
ER
AG
E T
EM
PE
RA
TU
RE
°C
WEEKS
0
20
40
60
80
100
120
140
160
180
200
# NUTS ABSCISED
# NUTS (No thrips dam)
# MATURE (No thrips dam)
WEEKS
0
20
40
60
80
100
120
140
160
180
200
# NUTS ABSCISED
# NUTS (Thrips dam)
# MATURE (Thrips dam)
ARC NELMAK D: MATURITY COMPARISON OF
ABSCISED NUTS WITH AND WITHOUT THRIPS DAMAGE
20 WEEKS
ARC VARIETY ORCHARD 816: MATURITY COMPARISON OF
ABSCISED NUTS WITH AND WITHOUT THRIPS DAMAGE
0
10
20
30
40
50
60
70
80
90
# NUTS ABSCISED
# NUTS (No thrips dam)
# MATURE (No thrips dam)
# N
UT
S
WEEKS
0
10
20
30
40
50
60
70
80
90
# NUTS ABSCISED
# NUTS (Thrips dam)
# MATURE (Thrips dam)
# N
UT
S
WEEKS 21
ARC VARIETY ORCHARD A16: MATURITY COMPARISON OF
ABSCISED NUTS WITH AND WITHOUT THRIPS DAMAGE
0
20
40
60
80
100
120
140
160
180
200
220
240
260
280
300
320
# NUTS ABSCISED
# NUTS (No thrips dam)
# MATURE (No thrips dam)
# N
UT
S
WEEKS
0
20
40
60
80
100
120
140
160
180
200
220
240
260
280
300
320
# NUTS ABSCISED
# NUTS (Thrips dam)
# MATURE (Thrips dam)
# N
UT
S
WEEKS 22
a b c
ARC NELMAK D: Photos of damage to nuts with thrips
damage, without thrips damage and 20 nut sample
tested for oil content and maturity (N.B. Stinkbug damage)
23
Identification
During the 2011-2012 season a
total of 44 062 specimens
collected and counted
A number of morphological
characters are used to identify to
species (i.e. setae, surface
sculpture, detail on antennae,
wing venation and setation)
Adults 1.0 – 1.6 mm long
24
Some of the thrips species being identified by Michael Stiller, ARC-PPRI National Collection of Insects: Biosystematics, Pretoria, South Africa
So far no S. aurantii (citrus) or Heliothrips haemorrhoidalis (greenhouse)
Thrips gowdeyi (Bagnall)
Thrips tenellus Trybom
Thrips pusillus Bagnall
Taeniothrips sp.
Scirtothrips ?combreti Fauré
Megalurothrips sjostedti Trybom
Hercinothrips sp.
Helionothrips sp.
25
Identification/Photos: Michael Stiller, ARC-PPRI Biosystematics, Pretoria, SA
26
Species of mites identified by Eddie Ueckermann, ARC-PPRI National Collection of Insects: Biosystematics, Pretoria, South Africa
Agistemus africanus (Stigmaeidae) Red Velvet Mite Photo: Edublogs.org
Anystis baccarum (Anystidae) Whirligig mite Photo: BugGuide.net
Hexibdella sp. (Bdellidae)
Snout Mite
Photo: Tom Murray
ALL PREDATORY MITES
Phytoseiidae Amblyseius herbicolus
Typhlodromus (Anthoseius) vescus
Typhlodromus (Anthoseius) celastrus
Neoseiulus barkeri
Bdellidae Hexibdella sp. near singula
Anystidae Anystis baccarum
Stigmaeidae Agistemus africanus
Tetranychidae Eutetranychus sp.
Mononychellus nr, heteromniae
So far no broad mite or citrus mites 27
Aims & Objectives: 2012-2013 Season
13 July 2012: Set up study sites and
began scouting and monitoring.
Continuing with identification of thrips
species and sorting into guilds,
incorporated temperature and rainfall in
data, working out phenology of
macadamia cultivars from photo data.
Aug: Soil application of Metarhizium
(entomopathogenic fungi) at some of
the sites.
Field collections: thrips complex
distribution of thrips in macadamia
growing areas of South Africa. Photo Source: Wikipedia.org
Metarhizium on cockroach 28
Acknowledgements:
SAMAC (Research Project Funding 2011-2012, 2012-2013)
Rhodes University, Grahamstown, South Africa (Scholarship 2011)
National Research Foundation, Pretoria, South Africa (Scholarship 2012-2014)
Ernst & Ethel Eriksen Trust, Bryanston, South Africa (Scholarship 2011 & 2012)
Mr Johannes Ngomane, Dr Schalk Schoeman, Prof Randall
Hepburn, Dr Eddie Ueckermann, Messrs Gerhard Nortjé,
Andrew Sheard, Alwyn du Preez and Len Hobson
Subtrop, Tzaneen, and ARC-ITSC, Nelspruit, South Africa
ERNST AND ETHEL ERIKSEN TRUST
29