Azalea Lace Bugs
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Lace Bugs on underside of leaf
Bug Central released Lacewings to control Lace Bug at the Mt Lofty Botanic Gardens near Adelaide last spring. This was very successful, and coming soon will be an updated page for this pest reflecting this work.
A range of Lace Bugs is found in Australia, with the Azalea Lace Bug (Stephanitis pyrioides) a major pest of Azaleas & Rhododendrons.
Lace bugs have between 2 and 4 generations each season. Juvenile lace bugs, or nymphs, are dark in colour and go through at least 4 instars or growth stages, before developing into adults. The adults are small, 4–6 mm in length, and have clear wings, giving them their common name of ‘Lace Bugs’.
Damage
Both adults and nymphs pierce the leaf surface and feed on the plant’s sap, causing mottling of the leaf surface. Whilst this is unsightly in low levels, under high pest pressure damage can cause defoliation and ultimately death of the plant.
Monitoring
Check the underside of leaves for nymphs and adults lace bugs. These will start to appear in spring and early summer.
Damage is similar to that of other sap-sucking insects such as mites and even thrips, although the damage tends to appear as coarser mottling compared to these other pests.
Control Options
‘Soft’ spray options such as oils and insecticidal soaps may be of some value, but are generally only effective in very low pest populations.
Broad-spectrum pesticides will have more control, but re-infestation can easily occur again, as the pesticide will also kill all of the predators and parasites in the garden, and a vicious cycle of infestation and chemical applications can start.
Predators may offer an effective alternative!
Lacewings - A Potential Solution
Adult Lacewing
Lacewings are an effective and efficient predator of a wide range of common pests in the garden, including Lace Bugs!
Lacewings & Lace Bugs are not the same insect!!
Whilst limited work has been done in Australia on using Lacewings against Azalea Lace Bug, a considerable amount of work has been carried out in the United Sates using similar lacewing predators to control this pest, with good results.
The Green Lacewing is a native to Australia and is found throughout all states. It has been used successfully by olive growers to control the Olive Lace Bug, and has shown in laboratory trials to also feed on other lace bugs.
Bug Central is confident this predator has the potential to solve one of the major problems Azalea and Rhododendron growers face.
The advantage of using these predators is they do the work of finding and killing the Lace Bugs for you. The need to apply a spray to every surface of every plant in the garden is time consuming.
Are you interested in trying Lacewings to control Lace Bugs in your Azaleas or Rhododendrons?
If so, contact Stuart Pettigrew: stuart@bugcentral.com.au
