Preventing and Reacting to Mealy Bugs

(In a new feature, Maximum Yield will help you concentrate on preventing and reacting to insects and disease that threaten your growing area)

There are many different reasons a hydroponic system can fall prey to insects or disease. The nitrogen balance might be completely off, there might be undetected water stress, or maybe it’s just too dry or humid. Plants can be very finicky, depending on factors that sometimes seem completely out of your control. As frustrating as that can be, it’s even more frustrating if you could have done something to prevent that problem.

When it comes to mealy bugs, prevention can be a bit tricky. Because a surefire way to prevent mealy bug infestation has not yet been discovered, one of the best prevention methods is simply a watchful eye. A simple inspection of the underside of the plant leaves should be sufficient. As soon as signs of infestation are seen on one plant, you must keep a close eye on the rest of the plants in the system. If you bring new seedlings or plants into your grow area, carefully inspect them to ensure that you’re not causing any unwanted stress.

Coated with a white, powdery, wax-like substance that makes them look like specks of cotton or common fungus, mealy bugs can sometimes be mistaken for spider mites. The difference is that spider mites appear more web-like. In hydroponic systems a mealy bug population can quickly build, thanks to ideal breeding conditions. Each female can give birth to over 200 young at a time, rapidly leading to plant damage.

The mealy bugs have a piercing and sucking apparatus that sucks the sap directly out of your plant. The plant will gradually die as it weakens. Leaves may turn yellow and drop off or disfigure, depending on the extent of the infestation. Mealy bugs also leave honeydew in their place, which can then turn into a black fungus known as sooty mould. If sooty mould is present, the upper side of the leaves will be covered with tiny dark speckles.

If infestation looks likely, you do have a couple of options for control. An oil-based spray or a natural predator should be enough, in most cases, to protect your plants. Oil sprays will suffocate the insects if combined with a good wetting agent. For the agent, you can use a synthetic or organic base. Neem oil is probably your best bet if you’re concerned with staying organic. Your local indoor gardening store should be able to direct you to some popular alternative sprays. Conventional sprays are very difficult to use because adult mealy bugs are water repellent, thanks to their waxy covering.

Your other option is to introduce a predator or parasite into your grow area. This is especially effective in areas where there is an established population of mealy bugs in a confined growing space. Common predators that you can bring into the environment effectively are the mealy bug predator ladybug Cryptolaemus, Laceworm larvae, or the Hypoaspis mite. Although you can try to bring in just one of the predators to deal with the infestation, pairing the Cryptolaemus with either the Laceworm or Hypoaspis will create a one-two punch that should knock out the persistent infestations.

Sadly, for heavy infestations, the only solution is to throw away the plant and growing media and start all over again. However, by taking precautions and acting at the first sign of infestation, you should be able to handle almost anything the pesky bug can throw at you.