Innovative Solutions to Management of Tospoviruses of Vegetable Crops
4 April 2019Strengthening Biosecurity for the Australian Vegetable Industry – Phase 2
4 April 2019Post‐harvest residues of most leafy vegetables rot within days after harvest and provide an ideal
environment for stable flies to complete their development. The resultant adult flies that emerge
seek blood meals several times a day and significantly affect any livestock nearby. Numerous
methodologies have been tried to reduce stable fly development from vegetable crop residues left in
situ after harvest but have either had limited success or are neither practical nor economically viable
for vegetable producers to adopt. The option of burying crop residues and/or compacting the sandy
soil above the residues offers a unique physical solution to preventing the emergence of adult stable
flies from the residues without the need to use pesticides.
Large‐scale field trials at commercial vegetable producers confirmed that burial and compaction of
post‐harvest residues is the most effective option for controlling stable fly. Compacting sandy soil
using a landroller almost totally prevents adult stable fly emergence from the soil. The hard barrier of
soil near the surface prevent the newly‐emerged stable flies from digging their way to the soil surface.
When the adult fly emerges from its pupal case in the soil, their outer exoskeleton hasn’t hardened,
hence they are quite feeble and unable to dig through compacted soil. By contrast, house flies are
bigger and more robust than stable flies, and are not affected by soil compaction (N.B. house flies
rarely develop from crop residues).