Post on 17-Jul-2015
Life history of a generalist predator on mixed and single prey: Studies of a red velvet mite (Balaustium
leanderi) showing big-bang reproduction
Karen Muñoz UNIVERSITY OF AMSTERDAM
IBED
Generalist predators
Balaustium leanderi fed on mixed diets
Messelink et al. Toft et al. Evans et al.
METHODS
Predatory mites collection
PREY COLONIES Greenhouse Whitefly Trialeurodes vaporariorum
Two-Spotted-Spidermite Tetranychus urticae
Western Flower Thrips
Frankliniella occidentalis
W S
T
COLONIES OF PREDATORY MITES
Experimental units Arenas for adults (Obtention of
Balaustium eggs) When eggs were obtained they were
kept on wet cotton wool
Experimental arenas to asses Juvenile development
When prelarvae hatched they were transferred to experimental arenas to asses Juvenile development
EXPERIMENTAL SETUP
Oviposition arenas
Juvenile development
TREATMENTS (Based on preliminary research Muñoz et al.
2009)
I) W 80
II) S 80
III) T 20
IV) W+S 40+40
V) W+T 40+10
VI) T+S 10+40
VII) W+T+S 30+30+6
Taken from the rearing and transfer with a fine brush
Prepared in advance: Clip cages on leaflets with whitefly aldults ovipositing
Larva
Nymph
Adult • Duration of each
individual • Fecundity • Mortality
RESULTS
LIFE CYCLE Average egg to egg development: 63.3 days
(22.1°C ± 2, RH= 75%)
7 d 6 d 8 d
7d
9d 8 d 17 d
0
10
20
30
40
50
60
70
80
W W+T T T+S S W+S W+T+S
Life
spa
n (d
ays)
bc bc a
cd
ab
d
abc
Immature development Preoviposition period
LIFE CYCLE DURATION
W W+T T+S T S W+S W+T+S
OVIPOSITION: Reproduction strategies
ITEROPARITY
SEMELPARITY (big –bang reproduction)
FECUNDITY
0
10
20
30
40
50
60
W W+T T T+S S W+S W+T+SNo.
egg
s/ in
divi
dual
b ab b
ab a
ab ab
W W+T T+S T S W+S W+T+S
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
W W+T T T+S S W+S W+T+S
Non
-rep
rodu
ctiv
e in
divi
dual
s (%
)
b a
a a
a
a
b
W W+T T+S T S W+S W+T+S
SURVIVORSHIP
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
W T S W+S W+T T+S W+T+S
Surv
ival
(%) W+S
W W+T T T+S S W+T+S W+S
W
S T+S
W+T T+S
T
LIFE
TAB
LE
0
5
10
15
20
25
30
35
40
35 40 45 50 55 60 65 70 75
l Tm
T
00.010.020.030.040.050.060.070.080.09
35 40 45 50 55 60 65 70 75Egg-to-egg developmental time
Other prey and combinations T S+W
r m
Net reproduction rate (R0 = lTmT)
Intrinsic rate of increase rm = ln(R0)/T
T W+S
• Reproductive performance increased on mixed diet of whitefly eggs and spider mite eggs
• Mixed diets may boost populations of erythraeid predators
• Future research: alternative foods/prey to boost erythraeid predator populations in the litter layer
CONCLUSIONS
ACKNOWLEDGMENTS
Luz Stella Fuentes Universidad Jorge Tadeo Lozano
Fernando Cantor Universidad Militar Nueva Granada
Arne Janssen University of Amsterdam IBED
Daniel Rodríguez Universidad Militar Nueva Granada
Maurice Sabelis University of Amsterdam IBED
Eudoro Mora Research assistant Universidad Jorge Tadeo Lozano
Biological control research group in Colombia
Population biology research group in The Netherlands