The aim of this project is to develop multispecies trapping strategies for the stored grain beetles Rhyzopertha dominica, Cryptolestes ferrugineus, Tribolium castaneum, Sitophilus oryzae (all established in Australia) and Prostephanus truncatus (not present in Australia) in outdoor environments.

1. biosecurity built on science
Project 2113 Combining monitoring and
incursion surveillance for grains
Mark Stevens
Principal Research Scientist, NSW DPI, Yanco
Plant Biosecurity Cooperative Research Centre

2. biosecurity built on science
The original objectives
• Can we monitor multiple species of stored product beetles on a single trap
without adverse pheromone interactions (Rhyzopertha / Tribolium /
Sitophilus / Cryptolestes)?
• Can we monitor simultaneously for an exotic pest (larger grain borer
Prostephanus truncatus)?
• WHY? If we can, then we get more efficient population monitoring /
sampling for assessment of phosphine resistance / early detection of a PT
incursion.

3. biosecurity built on science
The evolved (additional) objectives
• Can we make the Cryptolestes ferrugineus pheromone lure work
more effectively?
• Can we make commercial Sitophilus oryzae pheromone lures work
outdoors AT ALL ?

4. biosecurity built on science
Strategy and results - interactions
• Interactions: Lindgren 4-unit
funnel traps, 300 m circle, 4
groups of 4 or 6. Pairwise
comparisons then individual lures
vs 4 lures together.
• Commercial Trécé lures for
Rhyzopertha, Tribolium and
Prostephanus, Research Directions
lure + 3 release tubes of ‘volatile
X’ for Cryptolestes.

5. biosecurity built on science
Strategy and results: 2-way interactions
• Most pairwise comparisons look
like this:
• Except this one:

6. biosecurity built on science
Strategy and results: 4-way interactions
• A component of the Cryptolestes
combined lure seems to increase
the attraction of Rhyzopertha.
• Nothing much else going on in
terms of interactions.
• But we don’t have Prostephanus
here – so work to start in South
Africa this spring.

7. biosecurity built on science
Better performance from the Cryptolestes lure
• Volatile X caught > 11 times
the number of C. ferrugineus
than the pheromone lure.
• Combining volatile X and the
pheromone lure led to > 2.8
times the catch of volatile X
alone.

8. biosecurity built on science
• More units on the LFT didn’t make a difference.
• More C. ferrugineus caught on the panel trap, probably dues to higher volatile X
emission rates.
Better traps for Cryptolestes

9. biosecurity built on science
• Trials in South Africa to be run by Prof. Johnnie van den Berg
this season – do Rhyzopertha / Tribolium / Cryptolestes
pheromones affect the response of Prostephanus to its
pheromone?
• Can we make Sitophilus oryzae lures work? Two choice pitfall
data suggests it may be possible.
What happens next?

10. biosecurity built on science
What happens next?
Table 2. Response of adult S. oryzae to volatile organic compounds in two-choice pitfall bioassays.
Compound Response Index (Mean ± SE)a
Total Males Females
Control (pentane vs blank) -1.84 ±11.39 -0.98 ±11.41 -6.58 ±12.38
1-octen-3-ol +32.02 ±7.99* +31.31 ±11.01* +35.80 ± 9.37*
trans-3-octen-2-one +31.57 ±11.24* +36.61 ±13.28 +30.77 ±12.12
hexanoic acid +7.17 ±13.14 +14.51 ±13.71 -2.74 ±15.77
nonanal +13.59 ±9.01 +19.36 ±11.83 +11.09 ± 8.54
2-ethyl-1-hexanol +19.92 ±9.46 +23.60 ± 9.04* +14.32 ±12.37
4’-ethylacetophenone +1.26 ±13.03 +3.07 ±16.29 +4.16 ±12.69
3-methyl-1-butanol +43.91 ±8.60** +44.45 ±10.23** +42.14 ± 7.97**
3-octanone +7.54 ±10.43 +9.68 ± 7.68 +4.09 ±14.52
2-phenylethanol +9.44 ±10.82 +13.50 ±10.88 +4.83 ±11.90
valeraldehyde -30.42 ±7.02*** -30.14 ±6.63** -29.57 ±10.78**

11. biosecurity built on science
End-users?
• For more information, please email
mark.stevens@dpi.nsw.gov.au
• Grain growers and handlers wanting to monitor pest populations to
optimise timing of grain handling operations and/or sample
populations for resistance testing, whilst also contributing to incursion
surveillance (Prostephanus).
• Researchers conducting ecological studies wishing to monitor multiple
species more efficiently (by avoiding the need to use one trap per
species).
• The future – efficient incursion monitoring for multiple exotics on single
traps?