Transcript Document

Advances understanding the
relationship between flower-thrips
and blueberries in Florida
H. Alejandro Arevalo and Oscar Liburd
University of Florida
Gainesville
2006
Flower thrips & blueberries
• Small insects ~1mm long
• Usually yellow-cream color
• Feed and lay eggs in flowers
• Petals
• Ovaries
• From egg to adult in 15 days
• Present only during
flowering period in
blueberries
General information
Flower thrips & blueberries
Sampling
Flower thrips & blueberries
Dispersion behavior
day 3
day 9
day 7
Day 1
6
0
1
2
5
3
3
2
1
1
1
0
0
1
2
3
4
5
6
1
2
3
4
5
6
7
1
0
0
1
2
3
X Data
X Data
Day 1
3
2
0
0
7
4
3
2
0
5
10
15
20
25
5
4
2
0
0
5
10
5
Y Data
4
Y Data
Y Data
0
5
10
15
20
25
30
35
5
4
6
6
Y Data
6
4
5
6
0
7
1
2
3
Day 3
Day 5
day 13
4
5
6
7
X Data
X Data
Day 7
day 17
day 21
day 15
Y Data
4
3
2
1
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
> 100
5
4
3
2
1
0
1
2
3
4
5
6
X Data
Day 13
7
5
4
3
2
1
0
0
0
6
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0
1
2
3
4
5
6
X Data
Day 15
7
0
5
10
15
20
25
30
35
5
4
Y Data
5
6
6
Y Data
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
Y Data
6
3
2
1
0
0
1
2
3
4
5
6
X Data
Day 17
7
0
1
2
3
4
5
6
X Data
Day 21
7
Dispersion
Size of thrips populations in relation to flower phenology
1
Percentage of open flowers
70
90
20
10
250
Average # of Thrips captured
200
 x 13.68  2
0.5  

 2.53 
f(y)  4.16 x column
192.9 1 vs
e y column 1
Col 1 vs Col 2
150
100
50
0
0
5
10
15
20
25
Days after blooming
R=0.9908; F = 107.8; df = 3,9; P < 0.0001
Flower thrips & blueberries
Management
E.I.L.
EIL
Number of insects
ET
Time
Flower thrips & blueberries
E.I.L.
% of fruit formed
75
y = -0.4032x + 62.726
R2 = 0.9377
70
65
60
55
50
0
5
10
15
No. of thrips per flower
20
25
Flower thrips & blueberries
E.I.L.
% of fruit damaged
2.5
2
1.5
1
0.5
0
0
1
2
3
4
No. of thrips per flower
5
6
Flower thrips & blueberries
EIL = 3 thrips / flower at flower opening
30 thrips / 10 flowers
Traps =
107 thrips in 16/63 of a trap
421 thrips/trap
E.I.L.
Flower thrips & blueberries
Conclusions
• White sticky traps and flower sampling are the best monitoring
methods for flower thrips
• Thrips are present in blueberry fields for about 25 days from
flower opening to ‘petal fall’.
• 7 days after bloom initiation the hot spots are defined.
• Once the hot spots are defined the population growth is
exponential for the next 10 days until ‘petal fall’ starts.
• The ELI is about 3 thrips per flower at the start of the flowering
period or 400 thrips per trap
Acknowledgements
• Florida Blueberry Association
• Miller’s, Straughn’s, Paine’s, Southland, and Mixon
Family Farm
• S- EPA grant #: X8-96424405-0
• Southern Region SARE #: GS05-12
• Small Fruit and Vegetable Lab at UF