hydrangeas (Hydrangea) are flowering shrubs that are often cultivated as bedding and solitary plants. They bloom around mid-summer and have different shades of flowers depending on the pH of the soil: for example blue, pink or white. Depending on the species and variety, some shrubs are hardy, but most species do best in full or partial sun and well-drained, moist soil. Hydrangeas are generally healthy, but pests such as mealybugs occasionally eat the leaves. Find out below how you can fight mealybugs on hydrangeas!
Fighting mealybugs on hydrangeas – identification
Mealybugs, also mealybugs (Pseudococcidae) are a type of scale insect. The adult females, which measure between 1 mm and 12 mm in length, are wingless and have a soft, oval and segmented body. They are grayish in color and their bodies are covered with a fine layer of wax. The males look like tiny flies. Young mealybugs, called nymphs, have pink or yellowish bodies when they hatch, but shortly after they begin feeding, they produce a protective wax that coats their bodies.
Hydrangea Pests: Mealybug Life Cycle
Adult male mealybugs do not have functional mouthparts, so they cannot eat and usually only live long enough to mate. Females lay up to 600 eggs at a time and the eggs hatch within one to two weeks. The hatched females, called “crawlers,” go through four stages of development before maturing into adults. The males go through five instars and can only eat during the first two stages of development. Multiple generations of mealybugs can be found on a hydrangea.
Damage to hydrangeas
Mealybugs have slender, narrow, tubular mouthparts and feed by inserting their mouthparts into hydrangea leaves and sucking out the plant fluid. They tend to colonize in large numbers on the undersides of hydrangea leaves. Severely infested plants may die or lose their foliage if the infestation persists for a long period of time. Scale insects typically eat more plant fluid than they can digest and excrete the undigested fluid as a sticky, sweet substance called honeydew, which drips onto the foliage and flowers. An unattractive black fungus called sooty mold forms on the honeydew deposits and impairs the plant's ability to photosynthesize.
What to do about mealybugs on hydrangeas?
Get rid of mealybugs with home remedies: homemade insecticidal soap
Combining a small amount of dish soap or isopropyl alcohol with a large amount of water to make homemade sprays and solutions is usually enough to kill mealybugs.
Get rid of mealybugs with natural remedies – neem oil
If the infestation is severe enough or you don't feel like making an insecticidal solution yourself, there are many products you can purchase to solve a mealybug problem. You canUse neem oil. Neem oil disrupts the growth and development of insect pests and has repellent and anti-rot properties. Best of all is thatit for honey beesand many other beneficial insects is non-toxic. Mix 30ml oil with 4L water and spray every 7 – 14 days as needed.
Assess the size of the mealybug infestation
Once you know how large the mealybug infestation is, you can decide how best to proceed. For a smaller infestation, it may be enough to dip a cotton ball in a solution of rubbing alcohol and water and clean the limited area they have occupied.
To combat mealybugs on hydrangeas: Repeat the treatments
No matter how large the infestation is, repeat the treatment daily for at least a week: there are almost always more mealybugs than you think once you notice an infestation. Repeated spraying or blotting will eliminate them all.
Eliminate mealybugs naturally
If you prefer to take the mealybug problem lightly, you can introduce the mealybugs' natural enemies into their environment. Beneficial insects such as lacewings and ladybugs eat mealybugs andother plant pests. Wasps also attack mealybugs.
Removing the infected plant
Unfortunately, sometimes it is best to sacrifice the parent plant to prevent further spread. Once you have removed the plant, inspect pots, tools, and other materials that came into contact with the plant for mealybugs and their egg sacs. Clean or discard any items that show signs of infestation.
Avoid problems with mealybugs by carefully inspecting hydrangeas before purchasing. Make sure there are no mealybugs or mealybug eggs on the foliage. Keep your hydrangeas healthy by providing them with the right amount of water and nutrients so they can survive occasional mealybug feedings without major damage. Do not overwater or overfertilize shrubs – mealybugs are attracted to plants with high nitrogen content and soft growth.
Spray hydrangea bushes with a steady but strong stream of water,to drive away the insects.
