Hibiscus Sawfly Control

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What Insecticides Kills Sawfly Larvae

Hibiscus Sawfly Control-white-hibiscus-flowers
White Hibiscus Flowers

Hibiscus are tropical/sub-tropical plants that produce an abundance of flowers that come in an array of colors, these perennials will enhance your garden with their many colorful blooms that come in all sorts of shapes and sizes. The hibiscus plant belongs to a mallow family Malvaceae and comprises some 679 species.

Besides their beautiful flower blooms, hibiscus are hardy plants that can withstand harsh conditions but like other garden plants hibiscus also have their share of garden pests issues that can reduce a beautiful hibiscus to a nightmare. Some of these pests are mealybugs, the pink hibiscus mealybugs, thrips, aphids, scales, whiteflies, leafhoppers, fungus gnats, and the hibiscus sawfly. We will be discussing however the hibiscus sawfly and how we can bring control.

Hibiscus sawfly biology

The hibiscus sawfly is a fly-like insect that belongs to the family Argidae, the adult fly is black  (316 inch) small, the top of the thorax is reddish. The larvae are 3/8-inch long spiny and green with dark or blackheads. There are several generations of this pest every year that are active during the warmer months

Signs of the hibiscus sawfly

The adult sawfly lays its eggs on the leaf’s underside, once the eggs hatch the larvae emerge and begin feeding on the undersides of the plant’s leaves, moving to the leaves uppersides as they become larger. Because of their huge appetite, they will consume the whole leaf except for the veins. The leaves and the flowers because of the mass feeding takes on a lace appearance. The life cycle of the hibiscus sawfly starts all over again as they pupate in debris around the base of the plants.

How to control the Hibiscus sawfly

There are several methods in which to control these sawflies, below we will be looking at some of these methods.

1. One method of control is by handpicking and throwing them into a container of soapy water. This method may require a bit of work but the end result is that you would have eliminated them.

2. Insecticidal soap has also proven to be effective, before applying insecticidal soap however read and follow the manufacture’s direction for the best results.

3. Soldier beetles are natural predators to sawflies, although the soldier beetle varies in color depending on their zone, one way to identify some of them are color spots that are black and large on each wing, the beetle also has a tan or yellowish color.

The larva hatch in the fall and begin feeding on soft-bodied insects along with the eggs of garden insect pests. During the colder months, they overwinter or hibernate in the fallen leaves or soil until spring arrives where they pupate or enter adulthood as a beetle. Soldier beetles are said to be among insects that pollinate plants as they can be seen flying among flowering plants such as zinnias, marigolds, hydrangeas, catnip, milkweed, goldenrod, etc… having these beetles in your garden is a win for you so installing some of these plants along with letting some of your herbs flowers will attract them to your garden.

4. Parasitic wasp is another means of biological control to control sawflies, the female wasp will deposit her eggs on the inside of garden pests. Once the eggs hatch the larva of the wasp will feed on the internal organs of garden insect pests causing them to die. After a while, the wasp will emerge from the dead body of the host insect.

These wasps can control many garden insect pests some of which include leaf miners, whiteflies, scale, caterpillars, cabbage worms, aphids, ants, cabbage loppers, European corn borers, codling moths, and tomato hornworms.

Some of these wasps are so small that they are difficult to spot except for the signs that they are present (dead garden insect pests). These wasps can be purchased from your nursery or garden center or you can attract them to your garden by installing plants that produce nectar and pollen. some of these plants include dill, fennel, cilantro, Queen Anne’s lace, yarrow, zinnias, Anise Hyssop, cosmos, etc…

5. Soapy water is also an inexpensive way to get rid of sawflies, just add this solution to a spray bottle and make contact by getting total coverage of the leaves. It’s also good to rinse the leaves with fresh water after an hour or so.

6. It’s also been recommended that a strong spray of water from your garden hose can also knock the larva of plants causing elimination.

7. The use of neem oil has proven to be effective against sawfly, read and follow the manufacture’s direction for the best results.

8. Diatomaceous earth is a favorite of many home gardeners that works well in the elimination of garden pests. Read and follow the manufactures direction for the best results.

9. A portable hand vacuum is said to be effective in manually removing the larva from garden plants.

10. The presence of lizards and birds will help in reducing the sawfly population.

11. Cultivate around shrubs and trees in the early spring and again in the fall to reduce overwintering populations.

12. Horticultural oils will bring elimination to the sawfly larva, before applying oil read and follow the manufacturer’s direction for the best results.

The final word on hibiscus sawfly control

Hibiscus are beautiful flowering plants that will give that color pop and the feel of the tropics, these garden beauties are widely used in many home gardens. I have worked with hibiscus on many garden projects and have never been disappointed, these flowering plants will go to work for you sprucing up your summer garden giving you flower bloom almost year-round. Don’t let the sawfly turn your dream hibiscus into a nightmare. Following this guide will help you to win the war on the hibiscus sawfly so your hibiscus can go to work for you by providing beautiful colorful flower blooms.

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About the author

+ posts

Norman loves being in the garden, both at home and for his job....
he is 'Natures Little helper' being outdoors, growing his vegetables and flowers from an early age.
Now having spent over 22 years in the profession he want to give some of his knowledge to others...
his vast array of hints and tips you will find scattered over this site will help you no end growing plants in your garden.

6 thoughts on “Hibiscus Sawfly Control”

  1. Thanks for sharing with us all this well written and very informative article here. I have always been more fond of wildflowers than garden flowers, but this has still been a very interesting read. However, i wouldnt have thought that soap water would have done any plants any good. Wont this kill them?

    Reply
    • You are so welcome and I am so happy to help, soapy water is a safe approach it won’t harm the plant if you apply it at the right dosage and the right time. It is also good to rinse the plant thoroughly with fresh water an hour to an hour and a half after applying the soap solution.

      Reply
  2. I had no clue that the sawfly posed a threat to hibiscus plants. You definitely went into great detail explaining what they are, why they are bad, and a variety of ways to go about getting rid of them. I feel like I would try using some of the water methods to eliminate them before deciding to introduce a different bug as a predator.

    Reply
    • I am so happy to help and it is best to use the most inexpensive safe methods first before moving to chemicals. Wishing you all the best of success.

      Reply
  3. Wow, talk about information…

    I’m not a gardener at all… my mother and grandmother were really big into it for flowers and small crops back in the day… so I had no idea that hibiscus sawfly was a thing.

    As far as ways to keep them away or reduce them, I’d go with the soapy water or the “lizard and bird” approach. I’m just not a fan of the others as I’m not a huge fan of bugs, haha.

    But this article is well written with great information. Although I didn’t know about these sawfly before I read the article, I’m glad I learned a little something today. 

    Thanks for the article, Norman! Great job. 

    Reply
    • It is always good to use the safe and natural approach when getting rid of insects pests, I am so happy to help, and thanks so much for your kind words. 

      Reply

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