Last year, after returning from a 6-week holiday, we noticed our Tahitian lime tree infested with black aphids. We have had small outbreaks before which are easily controlled but nothing like this. Here is how we control them.
What are aphids?
Aphids are small soft-bodied sap-sucking insects that suck all the nutrients out of your plant, leaving nothing for the plant. Aphids multiply quickly with each aphid producing up to 80 new aphids. An aphid’s life span is about 25 days.
How to Control Aphids
The best way the control aphids is to catch them early when they have only infested a few leaves or a young shoot. When we find aphids in small numbers, we just squish them, then give the area a high-pressured blast of water. Inspect the plant frequently for the coming weeks for them reoccurring.
Sometimes due to life, business, or just being away on holidays, aphids can take over a plant in a matter of weeks. When we left for our holiday the lime tree had no aphids on it and by the time returned home it was covered on every branch with aphids and the lime tree was looking sad. The first thing we did was to check the plant over for signs of any beneficial insects, such as ladybirds that would take care of the aphids. In our case, we didn’t find any.
We then sprayed the lime tree on dark with a horticulture oil, waited a week and resprayed. This had taken care of most of the aphids and by this time spring was on the approach and the ladybirds and wasps had moved in were taking care of the aphids.
There are a couple of other ways you can control aphids, some of these are soap spray, garlic spray, chilli spray, neem oil or sucking them off with a vacuum cleaner. You will also find ants working in conjunction with aphids, they harvest honeydew directly from them. If you can identify these ants they will be on the same plant and stop them.
My citrus tree looks sick after the aphids
After an infestation has been bought under control on your citrus tree, it will be lacking nutrients and looking quite unhealthy, so we recommend foliar feeding your tree once a week for 3 weeks, as well placing some slow-release organic fertiliser around the base of the tree and watering this in. This will help your tree recover.
How can I prevent aphids in the future?
The truth is aphids will always be there, so there is no way to prevent aphids but you can develop a healthy ecosystem in your backyard to give a home for beneficial insects like the ladybirds, wasp and lacewings to live.