1. Assessment of Spider Families
Clubionidae, Lycosidae & Theridiidae
as Potential
Biocontrol Agents of
Brassica Pests
Madaline HealeyMadaline Healey

2. Project Aim
“to determine the potential of Clubionidae,
Lycosidae and Theridiidae to control
Plutella xylostella,
Crocidolomia pavonana &
Myzus persicae
in Brassica vegetable crops….”

3. Brassica Vegetable Pests
• Diamondback moth
Plutella xylostella
• Cabbage Cluster
Caterpillar
Crocidolomia pavonana
• Green Peach Aphid
Myzus persicae

4. Brassica Vegetable Pests
• Diamondback Moth
P. xylostella
• Cabbage Cluster
Caterpillar
C. pavonana
• Green Peach Aphid
M. persicae
Diamondback larvae damage

5. Brassica Vegetable Pests
• Diamondback Moth
P. xylostella
• Cabbage Cluster
Caterpillar
C. pavonana
• Green Peach Aphid
M. persicae Cabbage cluster larvae damage

6. Brassica Vegetable Pests
• Diamondback moth
Plutella xylostella
• Cabbage cluster
caterpillar
Crocidolomia pavonana
• Green Peach Aphid
M. persicae
Green peach nymph damage

7. Background
• Chemical resistance
• South East QLD Lockyer
Valley survey
– 70% utilise IPM
– 30% consciously protect
natural enemies
• Spider dominant natural
enemy in Brassica
vegetables

8. Spiders in Brassica
Vegetables
Clubionidae
-hunting plant dweller
Lycosidae
-hunting ground dweller
Theridiidae
-tangle web-weaver

9. Spiders in Brassica
Vegetables
Clubionidae
-hunting plant dweller
Lycosidae
-hunting ground dweller
Theridiidae
-tangle web-weaver

10. Spiders in Brassica
Vegetables
Clubionidae
-hunting plant dweller
Lycosidae
-hunting ground dweller
Theridiidae
-tangle web-weaver

11. Spiders in Brassica
Vegetables
Clubionidae
-hunting plant dweller
Lycosidae
-hunting ground dweller
Theridiidae
-tangle web-weaver

12. Spiders in Brassica
Vegetables
What impact will these spiders have in
reducing pests?

13. Objectives
• determine the ability of three spider families to
reduce pest populations
• determine if a connection exists between spider
and prey preference
• determine spider predation potential as a
naturally occurring biocontrol agent in Brassica
vegetables

14. Laboratory Experiments
Exp 1
No choice Lepidoptera
predation
Diamondback & Cabbage cluster
Five larvae per trt
Six trts, 2 controls
Consumption after 24 hours
Exp 2
Lepidoptera prey preference
Diamondback & Cabbage cluster
One larva of each prey
Three trts, one control
First prey attacked
Exp 3
Lepidoptera prey
preference
by Lycosidae
Diamondback & Cabbage cluster
One larva each prey
One trt, one control
First prey attacked
Exp 4
Prey species preference
Cabbage cluster & Aphid
One larva each prey
Three trts, one control
First prey attacked

15. Experimental Collection
• Colonies
– Diamondback moth
– Green peach aphid
• Organic broccoli
plantings
– Spiders
– Cabbage cluster egg
rafts
Cabbage cluster egg raft

16. Experimental Arena
Caged arena with broccoli
seedling

17. Experiment One
Lepidoptera predation
• Two-factor ANOVA
• No significant difference
between prey mortality
P = 0.715
• No interaction
P = 0.195
• Spider families will
readily predate both
prey
• No significant difference
between treatments
LSD = 1.361
Mean live larvae after 24 hours
0
0.5
1
1.5
2
2.5
3
3.5
4
Clb&DBM
(Trt1)
Clb&Croc
(Trt2)
Lyc&DBM
(Trt3)
Lyc&Croc
(Trt4)
Thr&DBM
(Trt5)
Thr&Croc
(Trt6)

18. Experiment Two
Lepidoptera prey preference
• Chi-square analysis
• Significant prey
preference
– Clear choice of prey
dependant on spider type
χ² = 0.010
DBM – Diamondback moth
CCC – Cabbage cluster
87.5
12.5
25
75
17
83
0 00
10
20
30
40
50
60
70
80
90
Clubionidae Lycosidae Theridiidae Control
Total % of larvae
consumed first
DBM
CCC

19. Experiment Three
Lycosidae prey preference
• Chi-square analysis
• No significant prey
preference
– Prey choice independent of
spider type
χ² = 0.157
33.5
66.5
0
10
20
30
40
50
60
70
Diamondback
moth
Cabbage cluster
caterpillar
Total % of larvae consumed
first

20. Experiment Four
Prey species preference
• Chi-square analysis
• No significant prey
preference
– Prey choice independent of
spider type
χ² = 0.117
CCC – Cabbage cluster
GPA – Green peach aphid
37.5
42.5
33.5
66.5
77.5
12.5
0
10
20
30
40
50
60
70
80
Clubionidae Lycosidae Theridiidae
Total % of prey consumed
first
CCC
GPA

21. General Discussion
• All spider treatments will consume three
Brassica pests
– Generalist predator more effective than
selective
• Prey preference
– Physical and behavioural characteristics
• Diamondback larvae active
• Cabbage cluster larvae sluggish
• Green peach aphid nymphs passive

22. Future Research
• Repeat experiments
– increase experimental
units
• Lycosidae on plant

23. Future Research
• Cage exclusion
trials
• Spider thresholds
– No. spider per metre²
Semi-excluded cage

24. Summary
• Clubionidae, Lycosidae &
Theridiidae will predate
Plutella xylostella
Crocidolomia pavonana
Myzus persicae
• Potential naturally occurring
biological control agent

25. Acknowledgements
Dr. Graham Brodie
University of Melbourne
Dr. Lara Senior
Agri-Science Queensland
Ms. M. Firell
Agri-Science Queensland