- Author: Rosie D
Bugs!
Do I spray insecticides for them? Nope! I grow my roses in a no-spray garden. There are a couple of ways that I get rid of them. One, I hit the plant with a strong blast of water from my hose. Make sure you spray the underside of the leaves. That will knock the little buggers to the ground, and they are too lazy to climb back up. Two, I squish them with my fingers. Now don't go euuuwwwwww! It works! Use gloves if you wish. Three, I have California native plants in my yard. They attract beneficial insects like ladybugs who love to feast on aphids. So, try doing these things to help remove aphids in your garden.
Hoplia beetles start as grubs in the soil. They grow slowly over the winter and then come out of the soil in the spring. They love to eat the flowers of your roses (their preferred diet) but will attack other flowering plants as well. You know you have them if you see holes in the petals of your roses. They will often hide in the center of the flower.
The best way to handle them? Pick them off with your hand and squish them or drop them in a bucket of soapy water. I have never been able to master the soapy water trick (I need a third hand for that), so I don leather gloves and squish them! Since they like light-colored roses, planting dark-colored roses might be helpful. You can also just cut off the flowers and dispose of them.
Unfortunately, sprays don't work to kill these little buggers. They love to hide in the interior of the blossoms, so it is difficult for the spray to get on them directly. If you do choose to try to use an insecticide to kill them, do not do it when bees and other beneficial insects are present as it will kill them as well. In about six weeks or so, the beetles will be gone for another year. One must have patience as a gardener. Dealing with Hoplia beetles is a good lesson in patience. By the way, I do try to get out and squish them twice a day. Once in the morning and once in the evening. It's an effective way to check on my garden and it is a great way to unwind from the day.
If you choose to use a chemical for spider mites, both horticultural oils and soap will work. Insecticides don't work on spider mites. They are a mite which is different species. So, check the label to see if the designation, “miticide,” is present. Pesticides claiming they are “for mite suppression” are usually weak and will not perform well or will require multiple applications.
Do not use them when bees and other beneficial insects are present. Do not use a dormant or horticultural oil when it is going to be over 80 degrees that day as it can burn your plants. Don't use it if it is going to rain. If you are going to use these chemicals, you must dress the part and use eye protection, a face mask, gloves and preferably suit up. Dispose of any leftover chemical properly and wash up/shower afterward (including washing your hair).
Fungal diseases
Another fungal disease you might see on your rose bushes is black spot. It looks just like the name says, black spots with sometimes feathery margins on your rose leaves. The spores of this fungal disease spread by splashing water, so don't sprinkle your rose plants at night. There are also rose varieties that are black spot resistant. So, look for those if black spot is a problem in your garden.
When your roses have completed their first bloom, it will be time to deadhead and feed them. You should get a nice second bloom about six weeks after the feeding.
Alice Hamilton! This antique rose is named after Alice Hamilton who was an American physician, research scientist and author. She was a leading expert in the health field and is considered to be the mother of occupational health in this country. This during a time when women could not vote! She became an M.D. at age 24 in 1893 when she graduated from the University of Michigan Medical School. She was the first woman appointed to the faculty of Harvard University in 1919. I could go on and on about this amazing woman, but I hope you check out her bio and her rose.
Until Next Time…”Teaching you how to grow a garden is better than giving you a thousand roses.” Matshona Dhliwayo
- Author: Kathy Keatley Garvey
It lived--and quite hidden at that--through the freezing cold, the rain, and the wind. It surfaced today on a milkweed in our Vacaville pollinator garden.
Surprise, surprise! We neither saw it as an egg nor as a tiny caterpillar.
"Most larval mortality in monarchs occurs in the first 2 or 3 instars.. so they keep as hidden and low-key as possible," entomologist David James, an associate professor at Washington State University, told us. "Once they make it to the fourth instar, they are emboldened and are more likely to be seen exposed."
James, who studies migratory monarchs, earlier commented on the fall breeding: "The egg laying females you are seeing now are likely migrants that have eschewed reproductive dormancy for reproduction. This has probably always happened to some extent but is likely more significant now because of warmer falls. The lack of activity in summer in Vacaville was probably a function of most of the population having dispersed further east and north, maybe more than usual? They surely did pass through Vacaville in spring on their way north but clearly didnt stop to use your milkweeds. It does seem that some years they are more prone to frequent stopping/oviposition on their way north and east, yet in others they just keep flying. There's evidence that the latter was the case this year... with as many migrants making it to BC as to Washington...Normally they stop in Washington and only a handful make it to BC."
James is the author of a newly published book, The Lives of Butterflies: A Natural History of Our Planet's Butterfly Life (Princeton University) with colleague David Lohman of the City College of New York. The book, released in the UK on Oct. 3, 2023, will be available in the United States starting Jan. 9, 2024.
Irish scientist Éanna Ní Lamhna recently interviewed the WSU entomologist in a podcast on RTÉ, or Raidió Teilifís Éireann. The book, Lamhna said, "showcases extraordinary diversity of world's butterflies, while exploring their life histories, behavior, conservation and other aspects of these most fascinating and beguiling insects." (See Bug Squad blog). Listen to the butterfly podcast here:
https://www.rte.ie/radio/radio1/clips/22294525/
Meanwhile, we checked another milkweed plant in the garden today and spotted another caterpillar, this one a little smaller and less active than the first.
As UC Davis distinguished professor Lynn Kimsey, director of the Bohart Museum of Entomology, commented: "So much for diapause!"
Now our milkweed garden includes scores of hungry aphids, several species of milkweed, two 'cats, and maybe three (one 'cat went missing and is probably j'ing somewhere) and four chrysalids.
Will we have a Merry Chrysalis?
The past few weeks have been “fun” with pest challenges in our garden and home. In the kitchen we battled ant infestations and pantry moths. In the yard the milkweed plants have been covered with oleander aphids, the California lilac (Ceanothus) was attacked by mealybugs accompanied by ants, and paper wasps (Polistes) have been trying to build a nest on the front porch.
How to tackle each of these issues? UC IPM (University of California Integrated Pest Management) Pest Notes and Quick Tips is my go-to for all these issues.
Inside the House:
Pantry Moths
Ants
In the garden:
Milkweed and oleander aphids (Aphis nerii)
I hoped I had escaped getting the detested orange oleander aphids this year, since in recent years they usually showed up earlier in the summer, but ultimately, they appeared. Most established plants can tolerate some aphids, but all aphids produce honeydew, which can attract ants and sooty mold. Since milkweed is the sole food source for the Monarch butterfly caterpillar, pesticides are not recommended. Thus, using strong sprays of water every couple of days helps manage them. Based on previous experience, I know they will reach the end of their life and ultimately disappear. https://ipm.ucanr.edu/QT/aphidscard.html
Mealybugs (Pseudococcidae)
Paper wasps (Polistes gallicus)
Thanks to UC IPM, which provides information on garden issues and pests, along with giving scientifically researched options on how to deal with them, I have managed to either control or eliminate these pesky pests.
UC IPM Resources:
The above links are to Quick Tips, short, to-the-point cards on each topic. They are available for free at local UC Cooperative Extension offices. The references below are for Pest Notes, which may have multiple pages and offer more detailed information about each topic.
Ants: https://ipm.ucanr.edu/PMG/PESTNOTES/pn7411.html
Pantry Pests: https://ipm.ucanr.edu/PMG/PESTNOTES/pn7452.html
Aphids: https://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html; https://ipm.ucanr.edu/PMG/PESTNOTES/pn7410.html
Mealybugs: https://ipm.ucanr.edu/PMG/PESTNOTES/pn74174.html
Wasps: https://ipm.ucanr.edu/PMG/PESTNOTES/pn7450.html
Denise Godbout-Avant has been a UC Cooperative Extension Master Gardener with Stanislaus County since 2020.
/h3>/h4>/h4>/h4>/h3>/h4>/h4>/h3>- Author: Lauren Fordyce
It may be after Labor Day, but some of your plants may still be wearing white, breaking that long-standing fashion “rule”! While many of us don't adhere to this old rule for our wardrobes these days, you may care about white stuff on your plants this time of year.
There are several white colored pest insects and diseases that you could be noticing on your plants.
Scales
Several types of scale insects are white. Each has their own host preferences, or plants they feed on.
- Cochineal scales feed only on cacti, usually prickly pears. On the outside they are white and waxy but have bright red bodies. If you scrape them off, you'll notice a red stain left behind.
- Cottony cushion scale feeds on a variety of woody ornamental plants. Common hosts in California are citrus, cocculus, nandina, and pittosporum. Adult scales are elongated and fluted.
- Euonymus scale feeds on many different plants but can be a serious pest to Japanese Euonymus (Euonymus japonica). Immature males are white and elongated with a brownish-yellow area at one end.
See the UC IPM Pest Notes: Scales to learn more about these and other scales and how to manage them.
Mealybugs
Mealybugs are whiteish-gray, oval, wax-covered insects. They can be found on many different plants, from fruit trees to houseplants, often hiding in protected places like branch crotches.
Powdery mildew
Powdery mildew often appears as white powdery spots (fungal spores) primarily on the tops of leaves. It can infect fruits and fruit trees, vegetables, and landscape plants in shady conditions when temperatures are between 60 to 80 degrees.
Whiteflies
Whiteflies are tiny insects with white, waxy wings and yellow bodies. They feed in large colonies on the undersides of leaves and have a very wide host range, including trees, vegetables, houseplants, and flowers.
Hackberry wooly aphids
This introduced aphid species infests Chinese hackberry and other hackberry (Celtis) plants. Hackberry wooly aphid adults appear in white, fuzzy masses on shoot terminals and leaves.
Spittlebugs
Adult spittlebugs are often brown, but they produce a white, foamy excrement on plants that looks like spit. They are known to feed on just about any plant.
Mushrooms
Many fungi produce white fruiting bodies that may pop up in your lawn, mulched landscape beds, or on trees and stumps. Puffballs and other fungi in lawns are mostly just a nuisance. However fungi on trees can sometimes cause wood decay and harm trees.
For more help diagnosing a plant problem or identifying a pest, see the UC IPM Plant Problem Diagnostic Tool or contact your local UC Master Gardeners.
- Author: Help Desk Team
Aphids can be a scourge in the garden. There are over 4,000 species of aphids in the world, but fortunately only(!) about 250 species are attracted to the plants we grow in our gardens and landscapes.
Aphids are small, slow-moving insects that come in a variety of colors—green, yellow, brown, red, or black. They sometimes match the color of the plant they feed on, but not always. They have long legs and antennae, and usually have a pair of cornicles (tube-like structures) sticking out of their hind end. No other insects have cornicles. Some adult aphids have wings—this can occur when populations are high or during spring and fall—that can allow them to disperse to other plants.
Aphid reproduction is interesting. Adult females can give birth to up to 12 live offspring each day without mating. During warm weather, many aphid species can grow from newborn nymph to reproductive adult in a week. No wonder it seems like they appear overnight.
Aphids are attracted to plants on which they can feed. Plants that are actively growing are prime targets. Right now, these include plants in our winter gardens such as kale and broccoli and landscape plants such as roses, but also the many winter weeds growing abundantly in many neighborhoods.
Aphids have sucking mouth parts, somewhat like little straws. They use them to suck sap (which is a plant's sugar source). What they excrete is commonly referred to as ‘honeydew' which contains sugar and is therefore sticky. Ants are attracted to this honeydew and will actively “farm” the aphids and protect them against natural predators.
Many plants, especially trees and shrubs, can survive just fine with low to moderate numbers of leaf-feeding aphids. Damage can occur with larger populations. Yellowing leaves and stunted growth are common.
Aphids can also transmit viruses from plant to plant on many vegetable crops and ornamental plants. Symptoms can include mottled, yellow, or curled leaves, along with stunted growth.
Controlling aphids
Understanding their life cycle is key to their management. By checking plants twice a week while they are growing rapidly, you can catch infestations early. With small populations of wingless aphids, hosing them off with a strong stream of water works well. Once off the plants, aphids are unlikely to be able to return. You can also prune out the most infested parts. Make sure you also remove nearby weeds that can serve as a reservoir of new infestations.
Natural enemies are important for aphid control. Parasitic wasps lay eggs inside live aphids, causing them to turn into mummies. You can recognize these by light-colored aphid bodies with circular holes on top where the wasp has emerged. Lady beetles (especially the larvae), syrphid fly larvae, and green lacewings are voracious eaters of aphids. See this website: https://ipm.ucanr.edu/natural-enemies/
If spraying with water is not effective enough, insecticidal soaps and oils are the best choices for most situations. Oils include petroleum-based horticultural oils or plant-derived oils such as neem or canola oil. These products kill primarily by smothering the aphid, so thorough coverage of infested foliage is required. Soaps and oils kill only those aphids present on the day they are sprayed, so applications may need to be repeated. Although these products can kill some natural enemies that are present on the plant and hit by the spray, they don't leave a toxic residue.
It is easier to manage aphids earlier in an infestation than later when populations are high. Some aphids cause leaves to curl around them, protecting them from sprays and beneficial insects.
Prevention
- When you purchase new plants, inspect them carefully.
- Don't over-fertilize. Excess fertilizers, especially too much nitrogen, can stimulate plants to put out lush new growth that will entice aphids to set up home.
- Excessive pruning can also stimulate plants to put out attractive new growth.
- Use a row cover, especially on seedlings and new plants. This will keep out aphids but also protect from other pests.
- Control ants that can protect aphids.
For more information, check these websites:
https://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html#TABLE1
https://ipm.ucanr.edu/QT/aphidscard.html
Help Desk of the UC Master Gardeners of Contra Costa County (SEH)