Hoya plants add a homey feel to your house with earthy greens and clusters of star-shaped flowers. It can be disheartening when you find your plant’s growth disturbed and its greens tainted black with mold.
If your Hoya plant is losing its radiance, it may be suffering from a common pest known as aphids. How do you identify aphids? And, most importantly, how do you get rid of aphids on a Hoya plant? Let’s find out.
What Are Aphids and How Can You Identify Them?
Aphids are tiny, soft, pear-shaped insects that suck on the sap in the plant’s stem. There are many species of aphids, and they come in red, green, black, or brown.
Despite their many species and colors, you can always identify aphids by their cornicles. These typically look like two short, thick antennas on their backside.
What Damage Do Aphids Cause?
Aphids thrive on the plant’s sap. Because of their high reproduction rates, they gradually start to drain the plant. This leads to a dwarfed growth, wilting leaves, and galls formation.
Also, aphids secrete a sticky layer called honeydew while feeding. Honeydew causes sooty mold growth that turns the leaves and roots black.
Finally, aphids can infect Hoya plants with mosaic viruses. They also increase the risk of infecting other insects like ants and ladybugs.
How to Get Rid of an Aphid Infestation?
There are two different approaches to aphid infestations on all varieties of Hoya plants.
The Non-Chemical Approach
First, check all your plants regularly and look for honeydew on the underside of leaves.
Once you spot even a tiny infestation, start applying aphid control. You don’t want them spreading from one plant to another and complicating the matter.
They can move from one plant to another if plants are close together. And even with plants kept apart, they can develop wings and find their way.
If your plant shows signs of a small infestation, prune out the infected parts. Then, try spraying the plant with a stream of water or a soapy water solution. That can be enough to throw off the aphids.
Always make sure you spray entire plant and the undersides of leaves as aphids can hide. Do so every two to three days for two weeks to combat the rapid reproduction rate.
If the water doesn’t work, you can try attacking them with lady beetles. They are natural enemies and can end the aphids problem once and for all.
Ladybugs have no damaging effect on your plant; their only preys are sap-feeding insects. They’ll only hang around until the aphids are gone.
Other natural enemies that can help you out are larvae, parasitic wasps, and green lacewings. You can buy the beneficial bugs online or from vendors.
Another thing you should do is make sure ants aren’t crawling up your hoya plant. Ants and aphids have a win-win relationship. Ants feed on the aphid’s honeydew and, in exchange, they protect aphids in their nests and provide them with some hygienic services.
You can trap wandering ants by using ant stakes or a band of sticky substances to stop them before they reach your plant.
You can opt for insect-killing fungus, too, such as Naturalis-O and Botanigard. They have both proven competent at wiping out aphids, even better than insecticides!
Last, one precaution to keep in mind is not to overuse nitrogen fertilizers. They’ll only increase the rate of aphid reproduction. Use slow-release fertilizers with a low nitrogen percentage.
The Chemical Approach
The chemical technique can be a bit aggressive, killing off beneficial insects along with harmful pests. So, it’s best not to use it.
An Aphid population is hardly ever deadly for mature plants. But, severe infestations that refuse to budge can demand the use of insecticides.
The mildest and best options are insecticidal neem oil, insecticidal soap, and horticultural oils. These dense substances work by stifling the aphids. So, make sure the substance reaches and covers all areas.
An option is to mix liquid soap, neem oil, and water. Or, you can replace the neem oil with alcohol. The alcohol dissolves the insect’s waxy covering.
Don’t use it concentrated or in large quantities, though, as it could burn the plant’s leaves.
Dilute the oils, soap, and alcohol with water and reapply a couple of times as their coverage isn’t long-lasting.
Other harsher options are sprays that contain pyrethrins, imidacloprid, acephate, or pyrethroids. But, these cause environmental harm in the long run and kill pests beneficial for your plant.