Bug of the Week: Rosemary Spittle Bug

Today the bug of the week should really come with “Smell-o-vision.” To really get the whole experience, pull out your jar of rosemary, slide off the lid and take a deep whiff. Ummm….

Okay, back to bug of the week. I was looking at our rosemary plant this morning. Rosemary grows great here as a landscape plant.

rosemary plant

It has tiny blue flowers that grow in clusters. The flowers are attractive to honey bees.

rosemary spittle bug

This morning what I spotted wasn’t a rosemary flower, however, it was a soft, white ball on the stem.

rosemary spittle bug

Any guesses?

rosemary spittle bug

This is the frothy home of the spittle bug. Or in this case, two spittle bugs. The bugs are relatives of aphids. They feed by sticking their straw-like mouthparts into the plant and sucking out the plant juices. They also excrete a bubbly material to hide in while they are feeding. The two insects in this photo are nymphs. When they become adults they will have wings and look like leafhoppers.

Don’t worry about me exposing the bugs for a picture. I actually had taken a picture of this one first.
rosemary spittle bug
Within seconds, it was already producing froth to cover itself back up again.

rosemary spittle bug

Wonder what it would be like to live in a froth house? Sure smells good, I bet.


  1. Lynnea

    I’ve been using Safer Insecticidal Soap on my rosemary spittle bugs.
    They are all nymphs.
    The froth washes right off and exposes the insect (half black, half cream) as shown in your photos.
    Will the soap kill the nymphs or must I remove them by hand?

  2. Roberta


    It has been my experience that the spittle bugs are seasonal and will disappear all on their own. If you have a particularly heavy infestation, you might want to look at whether your plant(s) are healthy. Rosemary plants grow best in full sun. As with many plants, they do not tolerate severe pruning or sheering very well.
    Good luck.

  3. Wingfoot

    Can spittlebugs kill rosemary if heavily infested and nothing is done to get rid of the bugs?

  4. Roberta

    They go away naturally here. Don’t know about anywhere else. It could be they are heavier on stressed plants, so make sure the plant is getting enough sun, water, etc.

  5. Debra Woods

    I have 100 rosemary plants that seemed to thrive when planted 6 months ago. I have had the spittlebugs for several months. I started with the organic solutions found online, now, Neem Oil & Take Down. I treated immediately when the first dozen or so showed up. I have sprayed, washed off, changed products. When I finished this last time two days ago, they were all gone. today there are hundreds again, more than ever. Is this a losing battle?

  6. Roberta

    It’s possible the rosemary plants are weak due to being planted recently. Try to keep your plants as healthy as possible with proper sunlight, water and nutrition.

    Here the spittlebugs disappear without treatment, but things may be different where you are. Check with your county Cooperative Extension office. They may have Master Gardener volunteers who can give you local advice.

  7. Maureen

    I just discovered these spittlebugs in NC in a particular type of pine tree. They certainly are gross looking!

  8. Virgi

    I have a beautiful rosemary plant for a few years, this is the first year it has been getting the spittle bugs. I use it for cooking, now I am not sure if it’s safe?

  9. Roberta

    The spittlebugs don’t really cause any harm. Just wash them off. If you think about it, they’ve only been feeding on rosemary.

  10. Virgi

    Thanks for your response, I used a spray bottle with water and dawn soap and it diminished a lot of the spittlebugs almost gone.

  11. Roberta


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