Advances understanding the relationship between flower-

thrips and blueberries in Florida

H. Alejandro Arevalo and Oscar Liburd

University of Florida Gainesville

2006

• 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

Flower thrips & blueberries General information

Flower thrips & blueberries Sampling

Flower thrips & blueberries Dispersion behavior

Day 1 Day 3 Day 5 Day 7

Day 21Day 17Day 15Day 13

Dispersion

R=0.9908; F = 107.8; df = 3,9; P < 0.0001

Size of thrips populations in relation to flower phenology

Days after blooming

0 5 10 15 20 25

Ave

rage

# o

f Thr

ips

capt

ured

0

50

100

150

200

250

x column 1 vs y column 1 Col 1 vs Col 2

22.5313.68x0.5

e192.94.16f(y)

10 70 20901Percentage of open flowers

Num

ber o

f ins

ects

Time

ManagementEILET

Flower thrips & blueberries E.I.L.

y = -0.4032x + 62.726R2 = 0.9377

50

55

60

65

70

75

0 5 10 15 20 25No. of thrips per flower

% of

frui

t for

med

Flower thrips & blueberries E.I.L.

Flower thrips & blueberries E.I.L.

0

0.5

1

1.5

2

2.5

0 1 2 3 4 5 6No. of thrips per flower

% of

frui

t dam

aged

Flower thrips & blueberries E.I.L.

EIL = 3 thrips / flower at flower opening

30 thrips / 10 flowers

Traps = 107 thrips in 16/63 of a trap421 thrips/trap

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