This document summarizes research assessing the potential of three spider families - Clubionidae, Lycosidae, and Theridiidae - to control pests in Brassica vegetable crops. Laboratory experiments showed that all spider families readily preyed on diamondback moth, cabbage cluster caterpillar, and green peach aphid, with some spider types exhibiting preference for certain prey. The research aims to determine if these spider families can effectively reduce pest populations and serve as naturally occurring biocontrol agents in Brassica vegetables.

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