Ask the Experts

My garden has had a serious ’bout of thrips infestation this summer. I have been removing all flower buds, sealing them in plastic bags, and disposing of them in the garbage container. I’ve tried spraying with spinosad, but thus far, it’s diminished their numbers, but they’re still present. Suggestions? I’m at my wit’s end.

– Sonoma County


Your approach is a good one. Good cultural control (such as removing the infested flowers) and using least-toxic insecticides (such as spinosad) are part of a well-rounded integrated pest management approach. You also might consider using reflective mulch or mesh around the infested plants, using row covers over your plants, and replacing the most thrip-prone plants with those that are less susceptible. UC Davis’ pest note about thrips has some excellent information.

– UCCE Master Gardeners of San Mateo/San Francisco Counties

I have a 1967 grand banks 32-foot wooden boat. It did have termites but I think I got rid of them, I will be checking again today to see if there are any droppings. I have these very small little round bugs and they either make a hole or they are going in and out of the holes made by the termites. I have been trying to put epoxy in the little holes. I will continue to spray termite spray and inset spray. Do you have any ideas how to get rid of them?

You would be best served by having a professional thoroughly evaluate your boat. From your description, you may have powderpost beetles, which lay their eggs in wood. The larvae eat through the wood, emerging from the holes they make. They often are present in the original wood. It may or may not be harmful, so that is another reason to get a good assessment. Visit the UC Davis pest note on wood-boring beetles for more information.

– UCCE Master Gardeners of San Mateo/San Francisco Counties

We have a black, sticky larvae-like substance on our pole green beans, and there are large holes in the leaves. We were not successful with the beans using Gardensafe fungicide 3.

We also have a cork screw willow tree that had small black insects on the bark that seemed to attract yellow jacket wasps, and they seemed to grow in size. When crushed they had a brown juice like tobacco. We used an insecticide and were successful in killing them, and the tree is recovering.

It is always good to bring a sample of your plant to your local Master Gardener or county extension office.

It sounds as if your beans may have aphids. The black sticky substance could be sooty mold, which develops on their excretions from chewing on the leaves. If the problem is aphids, a fungicide would not help.

Aphids are eaten by yellow-jackets and some other insects, and that could be why you noticed wasps on your willow tree.

Here is a link to information about treating aphids: Visit the UC Davis pest note for more information about treating aphids.

– UCCE Master Gardeners of San Mateo/San Francisco Counties

I have a problem with small gnats that look like small mosquitoes. I can not figure out where they are coming from. They seem to hang around the water faucets inside of my home. They are annoying and seem to be growing in number. The closest thing that I have found to match a description of these gnats is a picture of what is called a fungus gnat. What can be done to get rid of them and where do they come from? Are they coming from the pipes in my sinks?

Although it is always best to bring your pest to a local Master Gardener or County Extension office for identification, it sounds like you have Clogmia Albipunctata or bathroom bug. It is a tiny fly that does look a little like a mosquito. It can be found in trash, drains and other wet spots. The best solution is to remove all standing water, wet debris and sludge in drains. Any water leaks should also be repaired.

– UCCE Master Gardeners of San Mateo/San Francisco Counties

I have Land Planarians in my yard and they really give me the creeps when they come out on to the patio. Worse than that I understand that they eat the earthworms and I have seen some mutilated earth worms. How can I get rid of these, I think my whole lawn is infected. Also I heard that they like to come out when the lawn is watered during the heat of the day. Please help, I hate these creatures.

Land planaria are thin flat worms up to 20 inches in length, with a hammer-shaped head and varying color. They reproduce by eggs (up to four inches long) or by regenerating damaged parts of themselves. They like dark humid environments, and are seen mostly at night or under objects. They are most common in subtropical areas but have come to other places in contaminated container plants. They can become entangled and eat earthworms. Smashing them only causes the remaining parts to regenerate. Strong sprays of vinegar or orange oil may help.

– UCCE Master Gardeners of San Mateo/San Francisco Counties

About a month ago I began noticing some brown colored moths in my house, however I paid them no mind thinking just a few common moths got in the house. But now that it has been a month I have noticed that the moths have multiplied rapidly and now I would call it no less than an infestation. After looking at your web site I realized the moths in my house look strikingly similar to the “Brown Apple Moth” depicted on your web site. I thought this would be important to bring to your attention seeing that your map of locations or infestations may be a bit off as of now. Oh yeah, it seems that we have been having white colored small fruit flies with red eyes in our house as well but I am unable to identify them. Thought this would be helpful.

– Fresno, California

It’s highly unlikely that it is the light brown apple moth inside your house, given that they primarily feed on landscape plantings, oaks, and agricultural crops, but since the light brown apple moth is a quarantine pest, it would be best to have it confirmed. For positive identification of the moth inside your home, take one of them to your local Master Gardener office or contact the Fresno County Agriculture Commissioner office and have them check it out.

– UCCE Master Gardeners of San Mateo/San Francisco Counties

I believe I have Mexican fruit flies in my Granny Smith apple trees. I would like advice on how to get rid of them. They come back every year and spoil about 90 percent of the fruit. Do I need to spray? If so what do I use, and when do I use it? Are there any agricultural agencies that come out and do the spraying for you? The trees are mature and quite tall, so it would be hard for me to reach the tops.

Mexican fruit fly is a serious invasive species. To know for certain what pest problem you have, please contact your county agriculture commissioner to get help with identifying the problem and recommending treatment. Your local Master Gardener office is also a resource for dealing with this problem.

– UCCE Master Gardeners of San Mateo/San Francisco Counties

I have one grape vine in my backyard which I think is being attacked by the skeletonizers – banded yellow and green bugs on the underside of the leaves. What can I do to rid the vine of the pest?

It is always best to bring a sample of your plant to your local Master Gardener or county extension office, but it sounds as though your grapes may be infested with spider mites, which are green and black, but are almost microscopic. On the other hand, you could have grape leafhoppers, which are typically pale yellow with dark yellow and black markings. They are easier to see, and eat leaves until sections die. They can be controlled by fall cleanup and early spring monitoring. It can then be treated with insecticidal soap and the introduction of predator insects.

– UCCE Master Gardeners of San Mateo/San Francisco Counties

Which way is better in getting rid of pests, organic, conventional or GMOs?

Organic (or non-toxic) pest control, when possible, is always best for the environment and for the food chain. This method includes mechanical removal of pests or diseased vegetation, non-toxic applications, and generally healthy cultivation practices.

GMO refers to genetically modified organisms, which are controversial as a way to control pest sensitivities, and are not thought to be preferable to the “organic” methods or integrated pest management.

More information about the safe and effective use of pesticides in the home and landscape can be found at http://www.ipm.ucdavis.edu/PMG/PESTNOTES/
pn74126.html.

– UCCE Master Gardeners of San Mateo/San Francisco Counties

What do you suggest for treatment of mites in honey bee hives?

Honey bee hives may be affected by two different kinds of mites, and each is treated in a different way. Honey bees themselves are quite susceptible to pesticides, so it’s important to know which kind of mites you have and how serious the infestation is before proceeding.

Varroa mites are small parasites that feed on the blood of the honey bee. Their populations may be controlled through any of several treatments; however, there is evidence that some mites are becoming resistant to treatment.

Tracheal mites, as suggested by their name, are microscopic parasites that spend most of their lives inside the breathing tubes of adult honey bees. As a result, tracheal mites are not very susceptible to contact poisons and are best treated with fumigants or “grease patties” on which the bees feed.

Specific treatment information for both Varroa and tracheal mites (including best timing for treatment), can be found on the UC Davis Department of Entomology Bee Briefs web page.

– UCCE Master Gardeners of San Mateo/San Francisco Counties