Olive lace bugs are sap seeking insects that feed on the underside of leaves. They cause a yellow mottling to the leaves surface, which usually turns brown and drops off. They can cause severe loss of energy, defoliation and reduced fruit yield. The pest is native to New South Wales and South Queensland, but are also found in other states. New infestations of the pests can occur regularly throughout the growing season and may have 3-4 generations per year.
The resulting stress and damage to plants from loss of tissue, fluids and nutrients can shock the plant out of production for 2-3 seasons, and may be longer if the plant is left untreated.
One way to treat this problem is with pyrethrum or you can choose an organic product to apply at the most critical time. If applied too early, eggs will not be killed and if applied too late, insects may fly and populate other trees. It is best to spray when 95% are hatched and 5% are flying. This gives a window of about 36-48 hours. The amount of time between hatched eggs to flying adults is between 7 and 10 days. When spraying, contact must be made directly with the pest, which are on the underside of the leaf.
Spot spraying is best used if only a few trees are infested, although regular grove inspections are required to stay on top of the problem. This method may postpone major intervention for extended periods.
For large infestations, spraying the entire grove at the onset will permit a baseline population point. Follow up treatments should be conducted as close to 10 days after the first treatment to allow unhatched eggs to hatch.
Mixing foliar nutrients, like seagold with the spray is beneficial, as olive leaves respond well to the rapid replacement of nutrients lost, thus reducing plant stress. Records of egg numbers and infestations should be kept as a future reference for further problems and outbreaks.
Don’t let pests get the best out of your grove!.
Contact The Olive Centre today and get the right advice and the best preventative methods to protect your grove.
NOTE: I have seen some sources which recommend the use of Mineral oils to ‘effectively’ control olive lace bug: Mineral oils (and plant-based oils such as Eco-oil based on canola oil) can work on newly-emerged Olive Lace Bug nymphs in the same way they work on scale nymphs. They suffocate them. But they are entirely useless on larger nymphs and adults eat the stuff! HIPPO is a combination of plant-based volatiles that can attract a number of beneficial species such as ladybirds and parasitoids. There is evidence that when plants are attacked, they give off various volatile compounds that are attractive to certain beneficials, and this is the technology that is being used in HIPPO-advanced Eco-Oil. Eco neem is the canola oil containing azadirachtin, the major active from Neem oil. Neem isn’t registered for food crops in Australia, and almost certainly won’t be- so cannot be legally used in olives. ( as at 13/8/15)
In relation to products to help prevent Olive Lace Bug, please check out the APVMA Website for the PERMITS: latest approvals OTHER APPROVALS: check pubcris database. Please note that Victoria already has a swag of chemicals already approved for use but the application rates as recommended on the label must be adhered to.
*** Please note: it is a legal requirement that label instructions are followed, if olives are not listed on the label of the pesticide, it is either not registered for use on olives or an off label permit is required.