Ghost ants aren’t all bad

Ghost ants are scavengers in the garden, eating dead insects and speeding the decomposition process. They also eat the larvae of small beetles, moths, and butterflies. Ghost ants will also put a significant dent in the local two-spotted mite population. In Venezuela, ghost ants eat the eggs of kissing bugs (Rhodnius prolixus). Kissing bugs are vectors for Chagas’ disease, which damages the heart and nervous system.

Ghost ant control

Ants are one of Earth’s most successful species. Controlling them is difficult, and it all starts with cleanliness. If ghost ants are haunting your home, put all foods into airtight containers and wipe up spills right away. Caulk cracks and other points of entry. These pests enjoy a little moisture, too, so eliminate leaks and condensation.

If you can control aphids, whiteflies, and other insects that produce honeydew, ghost ants will find your garden less attractive.

Ant baits are effective against ghost ants. The closer they are placed to the nest, the most effective they will be. Just follow the ant trail. Also, make sure outdoor plants are not touching your house. Those stems make excellent insect highways to your home.

Apparently, if you crush a ghost ant, they smell like rotten coconuts.

Note: If your ficus tree keeps dropping its leaves, give it more water and be sure it’s near a sunny window.

Now you know.

Rhizopus head rot is the most common fungal disease of sunflowers, and it can result in losses of up to 100%.

It starts with a tiny wound and ends with the entire head rotting where it stands. Three different fungi can cause Rhizopus head roti: Rhizopus stolonifer, R. oryzae (syn. R. arrhizus), and R. microsporus. These fungi are everywhere. They are found in the soil and are easily disturbed and spread by the wind. These are the same fungi that cause bread molds and soft rots in carrots, melons, raspberries, sweet potatoes, and many other crops. 

Rhizopus head rot symptoms

The fungal spores that cause Rhizopus head rot first make their way into your lovely sunflowers through wounds caused by birds, hail, rubbing, and insect feeding by head moths and other pests. At first, these wounds look like small holes or dark spots on the back of ripening heads. Those spots start to rot, eventually drying to a dark brown. As the disease progresses, heads dry prematurely, and the interiors look shredded.

You can differentiate this disease from others, such as bacterial head rot or Sclerotinia head rot, by the presence of gray threads (mycelium) and tiny black reproductive structures (sporangia) within the shredded tissue.

Pickleworm lifecycle

These moths are only active at night. Each adult female lays 300 to 400 tiny pickleworm eggs in small clusters on new buds, and flowers, and shoots. These tender plant tissues make the perfect meal for pickleworm caterpillars, who eat voraciously for two weeks, going through five instars. Then they curl themselves up in dead leaves where they pupate for 8 to 10 days and turn copper-colored. There can be up to four generations each year.

Pickleworm management

Pickleworms cannot handle extreme cold (yet), so winter weather often takes care of the problem for some regions. Pickleworms have several natural predators, such as soldier beetles and ground beetles, but these predators cannot eliminate the problem. Bacillus thuringiensis (Bt) can be used but is only marginally effective because of where these pests feed and hide. Pickleworm moths are not attracted to light and there are no pheromone traps available, so what’s a gardener to do?

Commercial growers facing pickleworm damage must resort to preventative sprays of insecticides. These sprays can also kill the honey bees needed to pollinate cucurbit crops. It’s a dilemma.

If pickleworms are a problem in your garden, you can buy Steinernema carpocapsae. These are parasitic nematodes that love to eat pickleworm larvae. Also, because these moths only fly at night and honeybees generally pollinate during the day, you can cover your cucurbits each evening with row covers and uncover them each morning.

I know it means more work, but those delicious cantaloupes and chocolate zucchini cake are worth protecting. And nobody wants wormy pickles.
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[Contact me if you'd like the chocolate zucchini cake recipe.]

​Dusky stink bug damage

Dusky stink bugs can damage several crops, but they seem to prefer fruit trees. Their favorites include apples, cherries, peaches, pears, and plums. As they feed, they create catfacing and dimpling in fruit. Those dimples allow other pests and diseases access to the fruit and rot quickly sets in. Early feeding can cause trees to abort fruit altogether. Your citrus, grapes, peppers, and tomatoes are also vulnerable to dusky stink bug feeding.


Dusky stink bug identification

All stink bugs have shield-shaped bodies. From above, dusky stink bugs look identical to brown stink bugs (Euschistus servus). They also look a lot like dreaded invasive brown marmorated stink bugs (Halyomorpha halys) and one-spotted stink bugs (E. variolarius). You can tell them apart, however. Dusky stink bugs are significantly smaller than brown marmorated stink bugs, and they have pointed shoulders (pronotum). Brown stink bugs have orange shoulder points and ‘duskies’ do not. Dusky stink bugs are smaller than most other stink bug species, ranging from ⅜” to ½” long and ¼” to ⅜ ” wide. They have long, slender antennae.


Dusky stink bugs tend to be dark brown to dark gray, depending on where they live and what they’ve been eating. And they have stripes on their sides. They get the tristimus part of their name from the three (sometimes four) spots found on their bellies, though they will struggle if you flip them over.

You can reduce stink bug habitat by eliminating weeds in the legume family. These pests fly, so it’s an ongoing battle. I recently had a stink bug fly up to my 7th floor balcony! Be on the lookout for stink bugs and stink bug eggs every spring and autumn.

Most other plants are referred to as passive selenium accumulators. These plants can absorb too much selenium and suffer toxicosis. This is especially true for grasses and cereals, such as barley.

Toxic soil can be corrected with something called phytoremediation. Phytoremediation takes advantage of the fact that some plants absorb toxins through their roots. Before plants can cough those toxins into the atmosphere through their stems and leaves (transpiration), the plants are harvested and disposed of safely.

Signs of selenium toxicity

Selenium toxicity appears as stunting, early leaf death, and chlorosis. Leaves of affected plants may wither and dry up. High selenium levels in the soil can also cause copper, iron, and zinc deficiencies. Of course, these symptoms can mean several other things, as well. You will have to consider symptoms, location, and the presence of the aforementioned plants in your analysis.

Too much selenium in the soil can make your edible plants toxic. This can be the result of native bedrock. It can also be caused by industrial runoff. If you suspect high selenium levels in your soil, contact your local County Extension Office or Department of Agriculture.

Predatory mite lifecycle

The life of a predatory mite is short. Once the eggs hatch, they quickly go through a 6-legged larval stage and two 8-legged nymph stages before reaching adulthood. In her 30-day life, an adult female predatory mite will lay up to 21 eggs on the underside of leaves, in flowers, and within the crevices of buds. Depending on the weather, those eggs will hatch in 1 to 4 days. There can be up to 10 generations each year.

It is difficult to know if predatory mites are present because of their size, but you can buy them. They will help protect your avocado, citrus, grape, plum, strawberry, and many other crops. Before you release your predatory mites, be sure to reduce dust in the area by giving everything a quick rinse with the hose. You’ll want to avoid broad-spectrum pesticides and miticides, as well.

Miticides are also known as acaricides. These pesticides specifically target members of the arachnid subclass Acari. If your garden plants are suffering from infestations of mites or spider mites, you may want to consider using miticides. Or you may not.

Organic mite control

Diatomaceous earth (DE) can also be used against mites and spider mites.  It desiccates them and kills them without leaving any chemical residue. Other food-grade dusts that also kill these pests without chemicals. These other dusts have an advantage over DE in that they do not contain silica. Breathing in silica dust is bad for us, too.

There are also predatory mites that prey on mites and spider mites.

Whichever treatment you decide to use, don’t apply it on a windy day. It and your money will simply fly away on the breeze. To be effective, sprays and dusts must coat the underside of all the leaves affected by mites or spider mites.

Now, about those rhinos

​Rhino poaching is being deterred by drilling holes in the horns of sedated rhinos and packing those holes with miticides. It doesn’t hurt the rhinos, but it brings on nausea, diarrhea, and convulsions in anyone who eats the horn, thinking it will provide them with some magical powers. And it won’t kill them. I think it’s the least punishment they should have to suffer for needlessly killing an endangered animal, don’t you?

Pea leaf weevil identification

Pea leaf weevil adults are one-fifth of an inch long, grayish-brown, and rather slender in physique. If you look closely, you may be able to see three pale lengthwise stripes down the thorax. Larvae are milky white with a dark head. Like other grubs, they tend to hold themselves in a C-shape. These larvae have no legs and are about the same size as adults. Eggs are white at first but turn nearly black just before hatching.

Pea leaf weevil lifecycle

These pests tend to have one generation each year. After overwintering in protected feeding grounds, adults fly and walk to new territories where female pea leaf weevils will lay 1,000 to 1,500 eggs on or near young legume plants. When those eggs hatch, the larvae enter the soil where they go through five developmental stages or instars. They feed heavily on the nodules that allow legumes to convert atmospheric nitrogen into a form they and neighboring plants can use for food. While these pests feed on all legumes, they only reproduce on peas and fava beans.

Pea leaf weevil management

Commercial growers apply insecticidal seed treatments before planting, but that’s probably not an option for the home grower. The good news is that black clock beetles, ground beetles, and rain beetles all love to eat pea leaf weevils. By mulching and applying aged manure and compost around your legumes, you can encourage these beneficial insects. This will also provide your legumes with any nitrogen they may need.

As always, avoid using broad-spectrum pesticides. Those chemicals end up killing off all your helpers. Bacillus thuringiensis (Bt) can also be used against these pests, but it only works on the weevils it touches. Eggs and larvae will be unaffected. These other tips can help protect your peas and other legumes from pea leaf weevil damage:

• Buy certified pest- and disease-free seeds and seedlings.
• Employ crop rotation.
• Reduce soil compaction with aged compost and mulch.
• Plant early-maturing varieties suitable to your microclimate.
• Grow peas away from other legumes, including alfalfa and clover.
• Use row covers.
• Keep plants properly fed and irrigated to help them recover from any damage that may have occurred.
• Completely remove pea plant debris at the end of each growing season and compost it or trash it.
• Handpick pea leaf weevils and drop them into a container of soapy water or feed them to your chickens.

​I hope that pea leaf weevils never find your garden.

I thought I saw a whitefly on my apartment windowsill, but I was wrong. It was a dustywing.

Unlike whiteflies, which can carry diseases and suck the sap from your garden plants, dustywings are beneficial predators. They prey on slow-moving invertebrates, such as aphids, mites, and scale insects. They also eat arthropod eggs, including corn earworms, mealybugs, and tomato hornworms.

Dustywing identification

These net-winged hunters are very tiny. Their wingspan can range from one-twentieth of an inch up to one-fifth of an inch wide. They are covered with a whitish or grayish powdery wax. They secrete that wax from glands on the abdomen, head, and thorax. [Imagine being able to create your wardrobe that way!] They have tan-colored translucent wings and short antennae. Eggs are oval, yellowish-pink to orangish, and somewhat flattened. Larvae are red and white.

Dustywing lifecycle

Dustywings are commonly found around woody plants. They are mostly active at dusk (crepuscular) and attracted to lights. Each female can lay up to 200 eggs. These eggs are laid singly on nearby leaves and on the bark. There are two generations each year. Each larva goes through four instars. And all that growing requires a lot of food. A single dustywing larva was recorded as eating 226 red mites. That’s what I call helpful!

​You can encourage dustywings to stay in your landscape by providing woody shrubs for them to live in and avoid using broad-spectrum pesticides. Have you seen dustywings in your garden? I released mine into the Seattle wilderness.

Do your cucumbers, melons, squash, and watermelons have spots? Do your pumpkins have warts? It may be papaya ringspot.

Barley yellow dwarf host plants

Barley, corn, and the ryegrass and fescue in your lawn are not the only plants that can become infected with this disease. All members of the grass family (Poaceae) are susceptible.This means that your millet, oats, rice, rye, ryegrass, sorghum, sugarcane, and wheat can also become infected with barley yellow dwarf.  It is the costliest disease worldwide of all cereal crops. ​

Barley yellow dwarf prevention

Fungicides are ineffective against barley yellow dwarf. Instead, good cultural practices are your best plan of attack. Since aphids are the vectors for barley yellow dwarf, planning your planting schedule around aphid migrations can help reduce the likelihood of disease occurring. I know that aphid migrations aren’t usually mentioned on the evening news. But regularly monitoring your plants for aphids will make it very clear when they arrive and start reproducing. Planting seeds at times when aphids and seedlings are less likely to occur at the same time will help reduce disease. These other tips will also help keep your garden plants healthy:

• Plant resistant cultivars.
• Eliminate grassy weeds and volunteer cereals.
• Spray heavy aphid infestations with insecticidal soap.
• Encourage beneficial predators and parasitic wasps with insectary plants.

All aphids are bad, but invasive black citrus aphids can kill your orange tree.

Well, not exactly.

Black citrus aphid identification

Also known as oriental citrus aphids and brown citrus aphids, they get the different color names because they change color as they develop. Adult black citrus aphids are black and shiny. Like other aphids, they can be winged or wingless. Nymphs are reddish-brown. And there are no eggs unless they live in Japan.

Black citrus aphid lifecycle

All black citrus aphids are female, and all of those females give birth to live young unless they live in Japan. For some bizarre reason, black citrus aphids occurring in Japan do lay eggs. In either case, those populations can explode in record time. It is estimated that a single black citrus aphid can produce more than 4,400 offspring in three weeks. Those offspring can start reproducing on their own when only one week old. You can see how things could quickly get out of hand. The network effect of all that reproduction can result in 600 billion aphids in a single season, all starting with one aphid.

Managing black citrus aphids

One way to reduce aphid problems is to only feed nitrogen to plants at the appropriate times and avoid shearing citrus trees. Shearing and nitrogen both stimulate vulnerable new tip growth. Also, ants protect aphids. You can eliminate that protection by wrapping the trunks of citrus trees with sticky barriers. You can also use sticky sheets hung in your citrus trees to monitor for winged aphids and other pests.

Natural predators, such as ladybugs, and parasitic wasps will help reduce aphid populations. You can attract these beneficial insects to your garden by installing insectary plants, providing water, and avoiding the use of broad-spectrum pesticides.

A powerful stream of water from your hose can dispatch large clusters of aphids which are then unable to return to the tree, but this treatment won’t get them all, and it only takes one. Insecticidal soap can also be used, but that treatment is only effective on the aphids it touches.

Monitor your trees regularly for signs of black citrus aphids and report any potential sightings to your local County Extension Office right away.

Citrus sadness is not a case of lemon tree depression. But citrus growers around the world are pretty sad about this plant pandemic.

Citrus sadness, more scientifically known as citrus tristeza virus (CTV), is the costliest citrus virus. It has killed more than 80 million citrus trees and made an added 40 million more citrus trees useless for growing edible fruit. And it spreads quickly.

First seen in South America in the 1930s, this disease was called “tristeza” which means sadness in Spanish and Portuguese. Citrus sadness attacks several citrus species and passion flowers (Passiflora gracilis).

If you suspect citrus sadness has found its way to your tree, contact your local County Extension Office right away.

Nobody wants scabby cucumbers, squashes, or melons, but sometimes it happens.