Goniozus wasps can sting, but you’ll never have to worry about that. Like many other parasitic wasps, adult Goniozus wasps mostly feed on nectar, sap, and other sweets. The benefit they provide is that they also parasitize pests of almond, apple, citrus, fig, pistachio, walnut, and coconut trees, as well as blueberries, blackberries, grapes, and strawberries.
Navel orangeworm, obliquebanded leafroller, and light brown apple moth caterpillars are favorite egg-laying hosts, giving Goniozus the common name of navel orangeworm wasp. Personally, I prefer Goniozus - in my mind, it’s the Gonzo wasp. These garden helpers also use banana scab moths and several insect pests associated with galls as hosts. Goniozus wasp description There are 20 different Goniozus wasp species, and they all look like tiny flying ants. Walking through the garden, you may simply see a very small, shiny brown or black wasp-waisted insect. Most insects who fit that description are beneficial, so resist the urge to swat them away. Instead, take a moment and see if you can tell what they are up to. Goniozus parasitism Similar to cuckoo bird species, which lay their eggs in the nests of other birds, Goniozus wasps are also known as cuckoo wasps because they lay their eggs in the bodies of other insects. Adult females use their stinging ovipositor (egg-laying tube) to paralyze their victims, injecting hosts repeatedly with venom. The venom of some Goniozus wasps is permanent, but not all. In those cases, the venom only lasts half an hour or so, so she has that much time to transport her victim, mostly by dragging the much larger host, to a good hiding spot. If necessary, she will continue to inject venom over several hours, if that’s how long it takes to get where she needs to go. Once tucked safely into a crevice somewhere, some females will feed on the juices of said caterpillar over the next few days, aiding in the development of her eggs. This does not always kill the host. In some cases, the host simply walks away, a little worse for the wear, until the eggs hatch and begin feeding from the inside out. Goniozus larvae go through several developmental stages over the next 2 or 3 days, attached to their host, ultimately spinning tiny cocoons around themselves before reaching adulthood. Apparently, Goniozus wasps have been observed paralyzing far more hosts than they can possibly use for egg-laying. No one knows why. How to attract Goniozus wasps Beneficial parasitic wasps can be attracted to your garden with insectary plants. Insectary plants provide the food and shelter needed by these garden helpers. Most insectary plants feature umbrella-shaped flowers commonly seen in carrot, dill, cumin, mint, and cilantro, or globe-shaped flowers, such as chives. Allowing these plants to go to seed not only attracts beneficial insects, but seeds then create perpetual, edible crops. Other insectary plants include cosmos, sweet alyssum, yarrow, dandelions, and borage. Adding these useful plants to your yard looks nice, too!
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Unlike beneficial parasitic wasps, hornets attack honey bees, steal honey, invade bat houses, girdle branches, and ruin summer picnics. So why would we want to tolerate hornets in the garden? What good can they do? Let’s find out! Hornet species Worldwide, there are 22 hornet (Vespa) species, including:
There are also 3 species of nocturnal Asian Provespa, which are not actually hornets. Despite their name, bald-faced hornets (Dolichovespula maculata) are not true hornets, either. There is only one true hornet found in North America: the European hornet (Vespa crabro). Introduced in the 1800s, this hornet is now found throughout the U.S. Hornet lifecycle Hornets are highly social insects. They live in large colonies, housed in papery hives, that are commonly built in dark crevices, such as dead tree trunks, under house eaves, and in your garage. Hives are made up of interconnected brood cells. Both the queen and workers can lay eggs. Fertilized eggs laid by the queen develop into sterile females, called ‘gynes’ while eggs produced by workers develop into males, called drones. Drones mate with the queen during ‘nuptial flights’. As a result, a hornet’s nest is largely populated by two nearly distinct gender-dictated populations. Workers care for the eggs as they move through larval and pupal stages, ultimately emerging as adult hornets. Hornet description Hornets and yellow jackets are both types of wasps, though yellow jackets tend to be smaller, with more yellow and black, while hornets tend toward more black and white or yellow and brown coloration. Most hornets average 3/4” to 1”, while queens can be 1-1/2” long. If you look closely, you might be able to see that a male hornet abdomen has six segments, while females have seven segments and a stinging ovipositor. Hornet stings and allergies Like many other stinging insects, hornets become aggressive when they feel accosted (swung at, stepped on, sat on, that sort of thing), or when they believe their food supply or the colony are threatened. Hornet stings are more dangerous to humans that other insect stings because they contain higher concentrations of acetylcholine. Hornet stingers are not barbed and can be reused many times. Also, when one hornet stings you, it releases chemicals that tell other hornets to sting you, as well. These same chemicals are also released when you kill a hornet or spray a hornet’s nest with poison, so be forewarned. If you are allergic to stinging insects, you should always carry antihistamines or an EpiPen with you. Signs of an allergic reaction include shortness of breath, swelling of the face, lips, or throat, severe itching, weak or racing pulse, nausea, wheezing or gasping. If any of these symptoms occur, get medical help immediately. Call 911, grab a family member, or a neighbor right away. These symptoms can quickly escalate into a life-threatening situation. Otherwise, follow these steps to ease your temporary pain:
You can also take aspirin or acetaminophen to ease the pain, just be cautious about mixing medications, as that can cause yet another medical problem. Generally speaking, you are going to feel really miserable for 30 to 45 minutes, moderately uncomfortable for the rest of the afternoon, and you may experience discomfort for a week or so. You may also want to apply hydrocortisone or calamine lotion to the area. Pastes made of baking soda or colloidal oatmeal can also sooth the area. If you haven’t had a tetanus shot in the past 10 years, that can be a good idea, as well. So, why would we want hornets in the garden? Hornet diet Adult hornets feed on sweets, such as fallen fruit, sap, and your lemonade. They also collect insects for their larvae. This is part of the reason why they cause us so much grief during picnic season. From a hornet’s point of view, it is simply defending a food source when it refuses to back down from your burger and fruit punch. In addition to your picnic, European hornets commonly chew up beetles, dragonflies, grasshoppers and crickets, katydids, locusts, mantises, moths, and other wasps. This pulp is then taken back to the colony, where it is fed to larvae in the nest. If you start having a hornet problem while dining outside, you can reduce the chance of stings by placing a plate of meat and fruit somewhat away from the picnic table.
If hornets become a problem around your home, try excluding them before poisoning them. Those chemicals tend to create more problems than they resolve. There is far more to wasps and hornets than you might expect. This group of insects is massive and it contains many beneficial insects. You may not be familiar with chalcidoid wasps, but odds are pretty high they’ve been working hard in your garden all along. The chalcidoid superfamily of wasps contains 22,500 known species, with an estimated 500,000 species yet to be named. One of those families in particular, the Chalcididae, gives us chalcid wasps. And figs. Chalcid wasp description Ranging from only 1.5 to 0.75 mm (1/50 - 1/100”), you could fit 12 to 24 chalcid wasps nose-to-tail across a dime, so you probably will never see one. If you could see them, you would understand how they got their name. The word ‘chalcid’ comes to us from the Greek word for ‘copper’ because most chalcid wasps are a metallic bronze or copper color, though some species are metallic blue or green, and some are the more classic black and yellow variety. Beneficial chalcid wasps
Most chalcids are parasitic wasps. They lay their eggs in several common garden pests. When the eggs hatch, larvae feed on the host insect before pupating into adult wasps. [I know, it’s sounds awful.] Those hosts include the eggs and larvae of flies, beetles, moths and butterflies, some spiders and nematodes, and true bugs. Since true bugs (Hemiptera) include aphids, leafhoppers, spittlebugs, thrips, whiteflies, and scale insects, I am all for more chalcid wasps! [Plus, I love figs!] Figs and tiny wasps While most chalcidoid wasps parasitize all those pests, a handful of them are phytophagous, which means the larvae hide and feed in stems, galls, seeds, and flowers. Fig flowers, in particular, are hidden clusters found inside a hollow structure called a syconium. Fig pollination is usually completed by tiny specialized wasps, such as chalcid wasps. But, not all chalcids are good. Chalcids as pests Other phytophagous chalcids are not so helpful. These tiny wasps are pests because they lay their eggs in seeds. When those eggs hatch, larvae eat the seeds of pistachios and alfalfa, among others, creating burrows and allowing fungal and bacterial diseases a point of entry. In many cases, sticky barriers can be used to reduce the damage caused by these pests. Most chalcids, however, are beneficial. You can attract chalcid wasps to your garden by installing insectary plants, such as yarrow. Wasps may have a bad reputation, but there are beneficial wasps, and ichneumon wasps [pronounced ick-NOO-mon] are one of those Good Guys. Well, mostly. Ichneumon wasps are parasitic wasps and they have been around for over 15 million years. There are somewhere between 60,000 and 100,000 different ichneumon wasp species in the world, with 5,000 species in North America. Clearly, with those numbers, there is significant variety in appearance. Ichneumon wasp description Like other wasps, the ichneumons have a narrow body and an even narrower waist. Some females have an especially long ovipositor, which is often mistaken for a stinger. Ranging in length from 1/10” to over 5” long, they can be black, brown, yellow, or some pattern combination of those colors. These wasps have 16 or more segments in their longer than average antennae. Ichneumons are solitary wasps. Common ichneumon prey Adult ichneumon wasps eat little or nothing. Their larvae, on the other hand, are voracious feeders of beetle, butterfly and moth, wasp, ant, fly, and sawfly larvae and pupae or chrysalises. This is what makes ichneumon wasps so helpful in the garden. They also parasitize beet armyworms, some spiders, and wood-boring grubs. Some ichneumon wasps do this by using their long antennae to detect prey, then inserting the ovipositor into the wood, plant, or soil, to strike their prey, piercing its skin and inserting an egg. Other ichneumon wasps crawl down the stems of aquatic plants to inject eggs into water-dwelling insects. Yet another ichneumon is the parasite of a parasite, making it a hyperparasitoid. This ichneumon lays its eggs in moth-eating ant larvae. She emits chemicals that confuse the ants as she does her deed. Ichneumon wasp lifecycle
Most parasitic wasps lay their eggs on, in, or near their prey, but ichneumon wasps kill their prey outright and then lay eggs. When the eggs hatch, larvae feed on the host’s body. After hatching and eating their host, ichneumon larvae spin cocoons and pupate in or near the exoskeletons of their first meal. When they emerge from their cocoon, they are adult wasps who go in search of a mate. These garden helpers do not sting and they are worth their weight in gold, so check before swatting at something just because it might be a wasp. [Swatting at wasps is usually a bad idea, anyway…} One of the best ways to attract and provide for beneficial ichneumon wasps is to plant coyote brush (Baccharis pilularis) and to maintain hedgerows. In 2015, dreaded chili thrips arrived in California from Texas and Florida. Originally from Southeast Asia or India, this pest first hit North America in 1991 and is expected to be a permanent part of our gardening experience from here on out. Let’s see what we’re up against. Before we do that, however, let’s get one thing clear. Whether you are talking about many thrips, or just one (and there is never just one), they are both referred to as “thrips”, with the “s” on the end. I know, it’s strange, but there it is. It comes from an 18th century word meaning “woodworm”, which is even more strange since these pests are disease-carrying sap-suckers. So, what does a thrips look like? Chili thrips description Like other thrips, chili thrips (Scirtothrips dorsalis Hood) are really tiny - often less than 1/20” long. That works out to 8 or 9 thrips, standing nose-to-tail, across the head of a dime. Their pale bodies are thin and they have dark wings, but you may never get that close. What you may see is light-colored flecks of movement as you walk past a plant. That’s your first clue there is a problem. Plants vulnerable to chili thrips Your habaneros and Scotch bonnets are not the only plants susceptible to these pests. In fact, over 100 species [no, make that 200 species], from 40 different plant families [rather, 70 families], have been identified. Host plants include fruit trees, such as apples, bananas, cashews, citrus, figs, lychee, mango, pears, and even the beloved cocoa bean. Other garden favorites include asparagus, basil, beans, blueberries, buckwheat, corn, eggplant, grapes, peanuts, sweet peppers, soybeans, strawberries, and tomatoes, as well as many popular ornamentals, including chrysanthemums, coleus, camellia, Gerber daisies, poinsettias, pyracantha, roses, snapdragons, and zinnia. Damage caused by chili thrips
Symptoms of chili thrips infestation are first seen as damage to the upper surfaces of leaves, creating yellowish-green or brown angular spots on the upper surface and a gray sheen on the under surface. Leaves may become thickened or start curling. As nutrients and water are pulled from the plant, stunting, bronzing, distorted or elongated leaves, and flower bud scarring are also seen. Severe infestation can lead to the complete defoliation of a plant and these pests can carry tomato spotted wilt virus, peanut necrosis virus, peanut chlorotic fan virus, and tobacco streak virus. Chili thrips lifecycle Female chili thrips insert eggs into leaves, petioles, fruits, leaf axils, in curled leaves, and in leaf litter. In other words, they can be anywhere. Those eggs hatch in about one week and go through two larval stages in the second week. A single adult female can lay 60 to 200 eggs in her lifetime. That works out to a lot of sap sucking, disease-carrying insects. Controlling chili thrips Fast moving, highly prolific, and devastating to many of our garden plants, chili thrips have already developed resistance to insecticides containing asbifenthrin, cyfluthrin, and permethrin, so don’t bother. As of 2016, chili thrips had not yet developed resistance to insecticides containing acephate, imidacloprid, and orspinosad, but that window of opportunity may already have passed, and who wants those chemicals on their food anyway? Spinosad is actually more effective and less damaging to the environment. Sticky barriers may be used to monitor for chili thrips, but they won’t control the problem. Your best defense against chili thrips is to encourage beneficial insects, such as green lacewings and minute pirate bugs. Certain predatory mites and thrips and parasitic wasps will also help in the battle against chili thrips. These garden helpers are all attracted to gardens with a wide variety of plants and flowers, a clean water supply, and the absence of broad spectrum pesticides. Sadly, releasing purchased predators into the garden rarely works out. If conditions are good, they will come to you. If conditions are not good, it doesn’t matter how many times you buy and release beneficial insects. They will simply leave or die. Dusty conditions should also be avoided. Give susceptible plants an occasional quick shower with the garden hose in the morning to make life more difficult for thrips of all sorts. Also, stressed plants are more susceptible to infestation than healthy plants. This is yet another reason for selecting resistant cultivars that are suited to your microclimate, putting them into quarantine until proven healthy, feeding and watering them when they need it, and then giving them a helping hand with row covers as they become hardened off to your garden. Since shearing cuts off the ends of all twigs, it should be avoided if thrips are suspected. It is simply too stressful for the plant. Reflective mulch may disrupt thrips flight, if you want to try that. Infested foliage should be removed, bagged, and taken to your local County Extension Office for identification. If you don’t have time for that trip, please throw the bag in the trash. Do not compost plant material infested with even one chili thrips.Compounding the problem, chili thrips damage looks a lot like chemical overspray, aphid feeding, and micronutrient deficiencies. Western grape rootworms are leaf beetles that eat the leaves of grapes, roses, and fireweed in spring and summer. If that weren’t bad enough, their offspring are found underground, chewing up the root system. The combined effect can be devastating.
These beetles are very small, averaging only 1/7” in length. This works out to 4 or 5 beetles standing end-to-end across a dime.
Unlike their more tan-colored cousins, western grape rootworms are usually black or reddish-brown with dull gray, yellow, or white hairs, and orangish-red antennae. Larvae are 1/4-inch long, C-shaped white grubs. These grubs have 3 pairs of prolegs, a reddish brown head, and black or brown mouthparts. Eggs are laid in clusters on old wood under loose bark. Male western grape rootworm beetles rub their legs together to attract females, the same way crickets and grasshoppers do each summer. Damage caused by western grape rootworms These beetles cut slit-like holes in leaves, shredding them to tatters. The leaves then dry up and die, reducing photosynthesis and food for the plant. Adult beetles may also be found feeding on berries, petioles, and the bark of new shoots. Underground, western grape rootworm larvae feed extensively on the root system and can cause considerable damage. Controlling western grape rootworms Since larvae spend most of their year 2-feet underground, control is generally only possible during spring, when larvae and adult beetles move to the surface. Monitor plants for signs of beetle feeding and handpick whenever possible. You can also use sticky barriers to capture beetles moving up and down the trunk. If you see a tiny beetle playing ‘possum, don’t be fooled. The western grape rootworm beetle uses that trick to avoid being eaten, often falling off a leaf, stiff-legged. With a name like Asian jumping worms, you might expect colorful, flamboyant gymnastics moving gleefully through the soil, helping your plants grow. Okay, that was a stretch. And it was mostly wrong. I say mostly because, while not colorful, these worms really can move. Also known as snake worms, crazy worms, and Alabama jumpers, Asian jumping worms writhe violently when disturbed. They can even drop their tail when threatened. Sadly, instead of helping plants grow, these voracious feeders strip an area of nutrients, destroying the top soil layer, and leaving desolation in their wake. This interrupts thousands of years of evolution and nutrient cycling, threatens biodiversity, and increases erosion. The invasives mixed bag Before we get into the Asian jumping worm story, let me remind you that our beloved European nightcrawlers and honey bees are also non-native species. Sometimes invasives can be a good thing. This is not one of those times. As with many other situations involving invasive anything, the problem lies in imbalances. North American forests and farmlands have evolved, over thousands of years, to use surface plant litter as slow-release food and secure habitat for countless microorganisms, insects, reptiles, amphibians, and other life forms. Asian jumping worms eliminate that layer and they do it very quickly. What are jumping worms? Our more sedate earthworms tend to be reddish brown with a raised white or gray partial band part way down the body. That band is called the clitellum. Asian jumping worms, which can range from 3 to 7” long, are gray to dark brown, with a smooth the clitellum that goes all the way around and is closer to the head end. Also, while shiny, jumping worms do not produce the slime seen on many earthworms. Regardless of how you feel about that slime, it is very useful in creating soil aggregates that allow for the healthy movement of air, water, microorganisms, and roots through the soil. Jumping worms also tend to be more rigid than our squishy earthworms. There are three species of Asian jumping worm: Amynthas agrestis, A. tokioensis and Metaphire hilgendorfi, with A. agrestis being the most commonly seen. Native to Southeast Asia, jumping worms are believed to have been brought to North America in potted plants, bagged soil, or nursery stock, though we don’t know exactly when or how. Asian jumping worms have moved quickly westward, in worm terms, over the past 10 years and are now found in Oregon. As you can imagine, these continued movements are not just worms traveling on their own. Asian jumping worms end up in plants, mulch, and soil, on shoes and equipment, in agricultural produce, and in batches of fishing bait. They get transported by us, one gets loose, the problem spreads. It’s easy to do because these jumping worms spend their winters as tiny, pinhead size cocoons, filled with eggs, they reach adulthood twice as fast as our familiar earthworms and red wigglers, reproduce more rapidly, and are more aggressive. They can also thrive in higher densities and eat a wider variety of foods. The real problem with Asian jumping worms is where and how fast they feed. Damage caused by Asian jumping worms Asian jumping worms are too efficient. That may sound like a good thing, but too much of a good thing can be a bad thing. Let me explain. As earthworms feed on fungi and bacteria that grow on decomposing organic material, they burrow into the soil, excreting castings that are filled with broken down plant and animal material, churning the soil and improving soil structure, soil health, water retention, drainage, and nutrient cycling. Everybody’s happy. Plants and organisms grow. Life goes on. Asian jumping worms are eating machines, quickly devouring all of the surface material in an area and leaving behind a trail of low-nutrient crumbles prone to serious erosion. Research has shown that jumping worm castes are different from those of other worms. Instead of the soft, brown, crumbly bits of plant food and soil amendment we associate with earthworm castings, Asian jumping worm castings look more like a pile of coffee grounds. Asian jumping worms process nutrients so rapidly that their feeding releases nutrients faster than plants can absorb them, causing the nutrients to be washed, blown, or leached away. These castings contain important plant nutrients, such as potassium and calcium, and they tend to contain higher levels of heavy metals, such as iron and aluminum. When those crumbles are eroded away, those nutrients are lost. As a result, Asian jumping worm feeding quickly converts healthy, loamy soil in to granular, more sandy soil that tends to be hydrophobic, which means water runs off instead of sticking around long enough for plants to absorb. These invasive worms also push nutrients so deeply into the soil subsurface that many shallow-rooted plants cannot reach those important nutrients, leaving them to starve. What can you do about jumping worms? In a word, be diligent. Asian jumping worms generally cannot survive freezing winters, but anything less than that and they can become a serious problem in your yard. You can help prevent the spread of these invasive worms with these handy tips:
Bottom line, earthworms create topsoil while Asian jumping worms destroy it. Of course, that’s an oversimplification, but I want you to understand how important it is that these pests are kept in check. *Mustard Test
If you suspect the presences of Asian jumping worms in your garden, conduct a mustard test using these steps:
Worms, or wyrms as they were originally called, don’t technically exist. Wyrms referred a huge collection of tubular, limb-less critters back in the 1700’s. Of course, we all know what I mean when I say worm, right? Sure, we’ve all seen earthworms and red wigglers. But what about the 3-foot bristle worms, or the 22-foot African giant earthworm, or, are you ready for it? What about the 190-foot oceanic bootlace worm?!!? Crazy, right? Worm description
Well, clearly, we don’t ave any 190-foot worms in our gardens. What we do have is long, squishy bodies that are easier to describe by what they don’t have. Worms do not have legs, true limbs, scales, lungs, a brain, a true digestive system, or a circulatory system. They breathe through their skin, which needs to be moist at all times. Dehydrated worms become paralyzed. You may be surprised to learn that many worms are not actually able to move themselves with muscles, the way we do. Instead, they move through the soil by the act of feeding. If you think about it, worms are one big food tube. Food is sucked into the mouth and passes through a pharynx, esophagus, crop, gizzard, and intestine, before being pushed out the other end. While worms do not have eyes, per se, some of them do have light sensing organs. Types of garden worms There are three different types of garden lifeforms that fall under the worm category:
Nematodes are round worms. Earthworms are segmented. And flatworms, such as land planarians are, well, flat. The flatworms and roundworms are known as helminths and tend to be parasites of one form or another. Worms improve soil Worms are an important part of decomposition, whether it is happening underground or in your compost piles. Worms improve soil structure and soil health, making life a lot easier for your plants. As worm populations increase, drainage and porosity, or permeability also improve. As worms eat, poop, and die, they create mucous-coated soil clumps, or aggregates, that have spaces for water, roots, and air to move through. These spaces, called macropores and micropores, are important factors in soil health. For example, in sandy soil, the spaces are very large and leaching can be a problem, while clay particles are very tiny and they hold tightly to water and nutrients, and often have compaction problems. Worms help offset those problems by helping to break down and decompose organic materials, improving soil structure, adding nutrients, and being part of the nitrogen cycle. Worms are an important part of the soil food web and they help keep plant and tree roots healthy. Food for worms Did you know that earthworms like coffee? It ends up that sprinkling coffee grounds around your yard is a good way to reduce compaction and a couple of fungal diseases. For some reason, worms tend to pull coffee ground deeper into the soil. We don’t know why. We do know that worms will eat dead plant material, insects, insect eggs, fungi, bacteria, dead animals, and even cardboard and paper. While we may all end up as food for worms, more often than not, it is the worms who become the entree. Worms are commonly eaten by birds, amphibians, reptiles, and many mammals. Skunks, moles, shrews, raccoons, and rats will all gobble a worm, given the opportunity, as will centipedes, beetles, and even other worms, such as land planarians. Worms that are not worms Caterpillars, such as the impressively large Achemon sphinx moth, carpenterworm, and tomato hornworm larvae are commonly referred to as worms, as are tiny pink codling moth larvae, apple maggots, armyworms, cutworms, inchworms, naval orangeworms, and destructive green cabbageworm larvae, as are the microscopic larvae of dryberry mites. The larval form of click beetles are also called wireworms. And some people call grubs worms, too, but I have no idea why Each of these not-worms is simply a developmental stage in a process of metamorphosis.. Help the worms in your yard Worms do not have much of an arsenal when it comes to defense. The best way to help the worms in your yard is to create a healthy environment that meets their needs. If you build it, they will come. These tips will help you create a worm-friendly habitat in your yard:
If you happen to use tower gardening or other containerized methods, you can always rescue a few worms stranded after a rain and add them to the pot. They and your plants will be better of! And if worms really fascinate you, you can also raise your own. This is called vermiculture. Your yard may look quiet on the surface, but there is a lot going on underground. Even when given time to rest, or go fallow, there are still billions of processes happening in the soil beneath your feet, and worms are an important part of those processes. Finally, there is a new threat in the world of soil organisms. This one is the Asian jumping worm. There will be more on that soon. What do peaches and potatoes have in common? The green peach aphid. Considered the world’s worst disease vector among garden plants, green peach aphids (Myzus persicae) love to feed on peach and potato leaves, along with dozens of other garden plants. Green peach aphid description Green peach aphids are generally found in colonies of winged and wingless adults and immature nymphs. Green potato aphids look a lot like potato aphids (Macrosiphum euphorbiae). While potato aphids can be seen throughout the plant, green peach aphids prefer hiding on the underside of leaves. Adults may be bright or pale green, with a dark patch on the back (dorsum). Nymphs are pale green, yellowish, or pale pink. Eggs are elliptical in shape and only 1/50” long. At first, eggs are green or yellow, but they soon turn black, making them nearly impossible to see. Green peach aphids have a rather bizarre lifecycle that is too complex for this venue. You can read an excellent summary about it at the University of Florida website, if you are interested in that sort of thing. Damage caused by green peach aphids Green peach aphids often overwinter in the egg stage on stone fruits, particularly on peach and peach hybrids, though apricot and plum are also favored. In spring, these eggs hatch and nymphs begin feeding on buds, flowers, and new stems. A few generations later, which only takes a month or so, winged adults move to summer feeding areas. It would probably be simpler to list the garden plants that do not attract green peach aphids, but you do need to know where to look for these pests. Summer feeding can occur on artichoke, asparagus, beans, beets, broccoli, Brussels sprouts, cabbage, carrot, cauliflower, cantaloupe, celery, chili peppers, corn, cucumber, fennel, kale, kohlrabi, turnip, eggplant, lettuce, mustard,okra, parsley, parsnip, peas, peppers, potato, pumpkin, radish, spinach, squash, sunflowers, tomatoes, turnips, watercress, and watermelon. Aphids prefer feeding on tender new growth. This leads to wilting, water-stress, and stunting. It also generates a lot of honeydew (sugary insect poop), which provides the perfect growth medium for sooty mold. Heavy aphid feeding can weaken a plant to the point of death. The bigger problem, as with nearly all aphid species, is that these pests carry diseases. Green peach aphids may infect plants with a variety of viral diseases, including:
If potato leafroll virus appears in your garden, it is a good idea to remove the infected plant, plus three other plants in every direction, to prevent green peach aphids from spreading the disease even further. This is yet another reason why it is so important to plant certified disease-free plants in the first place. These pests are often found in greenhouses, so placing new plants in quarantine can go a long way toward preventing an infestation. They can also travel on the wind, so it's a constant battle.
Green peach aphid management The best way to control green peach aphids is to hit them in winter. This means removing overwintering sites, such as infested leaves, spent plant debris, and nearby weeds. Malva is a popular winter wonderland for aphids, so keep that weed away from your peach trees and potato plants. Bindweed, lambsquarters, penny cress, pigweed, sowthistle, tumbleweeds, white goosefoot, and rouge members of the nightshade family can also provide overwintering sites for this pest. As spring and summer come around, however, you can attract and protect beneficial predators, such as lady bugs, lacewings, parasitic wasps, and syrphid flies, by providing fresh water, planting a variety of insectary plants, and avoiding the use of broad spectrum pesticides. Most chemicals designed to kill aphids cause more harm than help by disrupting the lifecycle of many natural predators. There is also a parasitic fungus (Entomophthora aphidis) that attacks aphids, but you can’t do anything about that one. Early each June, in northern California, green peach aphids migrate into our gardens. You can prevent a full-blown infestation by monitoring plants on a weekly basis and using a damp rag or paper towel to wipe off colonies before they can really start propagating. A single female, hatched in spring, can reach sexual maturity in only 10 days, creating 20 generations in a single year. By the end of summer, this can result in billions of offspring. Two-spotted spider mites can kill off many of your garden plants as temperatures rise and humidity drops. Before a hot, dry summer kicks in, it’s a good idea to know what to look for. Two-spotted spider mites (Tetranychus urticae) can become a serious threat to your citrus and other fruit trees, most vegetables, and many ornamentals, such as marigolds, roses, and salvia. Beans, blackberries, blueberries, cucumber, eggplant, lettuce, peas, squash, strawberries, and tomatoes are all favorite foods of the two-spotted spider mite.
Two-spotted spider mite description As arachnids, all mites have two body segments and eight legs. Two-spotted spider mite eggs are round to spherical, but very difficult to see. Instead, you may see the webbing used to protect those eggs. Colorless larvae, which start out with only six legs, go through two developmental stages to reach greenish-yellow, eight-legged adulthood. This transformation can occur in as little as 5 days, and females can lay 120 eggs in their lifetime, so populations can rapidly explode. An interesting note, unfertilized eggs hatch into males, while fertilized eggs hatch as females. This is called arrhenotoky. Males are smaller and have narrower bodies and are more active than females. These close cousins to red mites are greenish-yellow to brown, with two dark spots, and they even have a red winter phase, but you probably won’t be able to see them without a hand lens. [Those dark spots are accumulated body wastes, so they are not always visible.] At only 1/50” long, two-spotted spider mites are easier to find by looking at the damage they cause. Damage caused by two-spotted spider mites As sap-sucking pests, similar to citrus mealybugs and citrus bud mites, these mites pierce plant cells and remove the contents. Hidden from view by feeding on the underside of leaves, they often go unnoticed until the damage becomes obvious. Mite feeding causes stippling and bleaching. These damaged areas increase, causing bronzing and early leaf drop. If you look at the underside of these leaves, you will often see the cast-off exoskeletons of mites. You may also see extensive webbing over buds, stems and flowers. Extensive feeding can cause stunting and even plant death. How to manage two-spotted spider mites Since two-spotted spider mites feed on such a wide range of plants, they are difficult to control. Mites favor feeding on stressed plants, so proper feeding and irrigation can help your plants seem less appealing to these pests. In addition, you can use these tips to reduce problems caused by two-spotted spider mites:
Predatory mites, such as Phytoseiulus persimilis, ladybugs, minute pirate bugs, and lacewings are all beneficial insects that feed on two-spotted spider mites, so keep you yard hospitable to these helpful predators. Mites are developing resistance to most chemical pesticides, but insecticidal soaps are effective against mites, with horticultural oils (not dormant oils) coming in a close second. These treatments are only affective against the mites that come into contact with it, so repeat treatments are often necessary. The ashy gray lady beetle is both stylish and deadly. We’ve all seen the red-domed ladybugs of popular culture with their shiny black dots, but what about the black lady beetles with red dots? There are four black lady beetles with red spots: twicestabbed lady beetles (Chilocorus orbus), Axion plagiatum, Chilocorus kuwanae, and the ashy gray (Olla v-nigrum). Unlike other lady beetles, however, the ashy gray has two forms, dark and tan. And they can change at will! Ashy gray lady beetle description Ashy gray lady beetles are sometimes ashy gray or tan, with black spots. At other times, they are black with red dots. Before they reach their domed adulthood, ashy gray lady beetles look more like tiny alligators with yellow spots. And before that, as pupae, they look like little orangish-yellow nubs. As eggs, they look like clusters of white or yellow, usually found on the underside of leaves, close to prey. Ashy gray lady beetle prey
While ashy gray lady beetles feed on the eggs of butterflies and moths, the lion’s share of their diet consists of aphids and psyllids. Since aphids and psyllids are disease-carrying, plant-sucking pests, we can use all the lady beetles in the garden as we can get. To attract ashy gray lady beetles and other beneficial insects to your yard, avoid using broad-spectrum pesticides, provide fresh, clean water, and install insectary plants, including dill, lavender, chives, mint, tansy, and yarrow. Rove beetles are a family of mostly elongated predators that protect your plants against a great many garden pests. There are over 63,000 different species of rove beetles (Staphylinidae), making them the largest beetle family in the world. There are approximately 4,360 species in the United States. Rove beetles have been around for over 200 million years and it may take another 200 million years to sort out this particular family tree. Currently, there are over 30 subfamilies of rove beetle, and scientists are still trying to sort it out. However these tiny beetles end up being related, the majority of them pack a wallop when it comes to devouring many common garden pests. Also known as trash beetles, these beneficial insects are often found in leaf litter, mulch, under loose bark, and around fallen trees. They may also be found in bird nests and rodent burrows where they presumably feed on fly and flea larvae. This huge family is extremely diverse. Some have evolved to live within caves, while others prefer living in mushrooms. Rove beetle description As you might expect from a family of this size, rove beetles come in a variety of shapes and sizes. Most of them are very small, averaging only 0.08 to 0.30 inches long, but they can range from 0.03 to 1.5 inches in length. Most rove beetles have a narrow body that can squeeze into tiny crevices in search of prey and shelter. Rove beetles can be black to brown, yellow to red, and even an iridescent blue-green. They have thread-like antennae with 11 segments; some of them have little knobs at the ends. Most rove beetles have short wing covers (elytra), which means you can see several abdominal segments. Many rove beetles look like a multicolored earwig without its pincers, but certainly not all. Rove beetle eggs are typically white, but can be spherical, pear-shaped or oval. Flattened larvae may have a distinct ‘neck’ or an armored head, though not all exhibit those characteristics. Pupae can be hard, dark colored cases, or naked white grubs, depending on the species. Adults tend to be long-lived. Many rove beetle species produce secretions. Some of these secretions help repel water, allowing clumsy insects to recover from falling into water, while other secretions can be particularly toxic. One of those toxic secretions, found in the Paederous group, is transferred from mother to offspring, at birth, providing protection against spiders. This secretion can cause skin irritation and it can damage your eyes. It is the most powerful animal toxin that we know of, but scientists are learning how to use it to heal lesions and treat cancer. Rove beetle diet Adult rove beetles eat mites and small insects, as well as root maggot eggs and larvae. Rove beetle larvae also parasitize root maggot larvae. The rove beetle diet is a Who’s Who of garden pests, including:
If eating all those pests weren’t reason enough to appreciate rove beetles, it ends up that adult rove beetles also pollinate cherimoya fruit.
You can help the rove beetles in your garden by avoiding the use of broad-spectrum pesticides and insecticides, and by maintaining permanent areas planted with bunch grasses or other low-growing perennials to provide year-round habitat for these tiny hunters. What types of rove beetles have you seen in your garden? Transpiration burn may sound like a bad deal, but it refers to the damage caused by mite feeding.
What is transpiration? Plants exhale water through tiny openings called stomas in a behavior known as transpiration. Stomas are generally found on the underside of leaves, but they also occur on stems and flowers. Stomas open and close to allow for gas exchanges necessary for photosynthesis [carbon dioxide in; oxygen out]. Transpiration also helps move plant nutrients, such as zinc, into and within a plant. The combined effects of plant transpiration and evaporation of water from the soil are called evapotranspiration. Maintaining the proper water levels within a plant is critical to its health. When mites start feeding, that balance changes. Types of mites There are over 42,000 different types of mites in the world. They can be black, yellow, green, brown, or red. They are tiny. Gall mites, spider mites, European red mites, and thread-footed mites are common garden pests. Some mites prefer buds, others raise blisters on plants, and others create rust patterns. All mites have piercing mouthparts used to suck nutrient-rich fluids from your plants. Transpiration burn occurs when mite feeding reaches critical levels. Symptoms of transpiration burn Mite feeding often causes leaf stippling. The loss of water and nutrients from countless microscopic punctures threatens plant health, especially in areas with scorching summers prone to drought. As temperatures rise, mite feeding increases and bronzing occurs. The accumulated water loss from mite feeding reaches a point where entire areas of the leaves die, leaving spots of dead brown or black tissue. Less leaf area means less photosynthesis, reduced crops, and unhealthy trees. Transpiration burn is a common problem of pear trees. Preventing transpiration burn A large, well-hydrated tree can lose up to 100 gallons of water a day during the peak of summer. Proper irrigation, using irrigation rings or soaker hoses, can prevent water stress on fruit and nut trees, helping them counteract the damage caused by mites. Mite control is tricky. These pests quickly develop resistance to chemicals, so pesticides don’t work. You can use a strong stream of water from a garden hose to displace mites. You can also buy predatory mites that hunt and feed on the mites feeding on your plants. Insecticidal soaps and oils can also kill mites, but use them carefully. They can cause sunburn damage and other problems. Keep your plants healthy and monitor them regularly for webbing and stippling, so you can deal with mite populations before they get out of hand. If you have a walnut tree, you should know about walnut scale. Even if you don’t, this is still an interesting read.
Walnut scale insects (Quadraspidiotus juglansregiae) have a unique behavior that makes them particularly fascinating. Like other armored scale insects, females protect themselves under round, dome-shaped covers. But walnut scale takes this concept to a whole new level. Walnut scale lifecycle Female walnut scale insects lay eggs in spring. These eggs hatch in only 2 or 3 days. Female crawlers move around a little bit, searching for a good spot to set up household. Once a spot is selected, they begin feeding and start building their protective cover. Male crawlers wander around, looking for a female. When they find one, they huddle up next to her, tucking themselves under the edge of her ‘skirt’, where they excrete their own elongated scale coverings. This often creates a daisy-shaped cluster of scales. After these groups mate, those females lay the year’s second batch of eggs. These eggs hatch, usually mid- to late summer, and stay in the crawler stage over winter. In spring, females claim real estate and males emerge with wings, which they use to find a female. Walnut scale description Walnut scale coverings start out white. This is called the white cap stage. Then they darken to gray or brown within a week or so. If you lift the covering off the central, round female walnut scale, you would see a yellowish body with indented margins. Other scale insects do not share those characteristics. Damage caused by walnut scale Like other scale insects, walnut scales use piercing mouthparts to suck plant juices from the cambium layer of twigs and branches. This weakens the tree, leading to branch dieback, cracked bark, and reduced harvest. Walnut scale feeding also increases the likelihood of canker development and fungal diseases caused by Botryosphaeria. How to control walnut scale You can’t control them if you don’t know they are present. Make a point of inspecting your trees regularly for signs of infestation and infection. You can apply sticky barriers near walnut scale adults to capture crawlers, as they emerge. There are many beneficial predators that feed on scale insects. Parasitic wasps, twicestabbed lady beetles, and a tiny black beetle that goes by the name Cybocephalus californicus, in particular, love to feed on walnut scales. Commercial growers apply insecticides during dormancy or when crawlers emerge in spring. Narrow range oils can also be used, but walnut trees are very sensitive to horticultural oils. Do not use oils on walnut during dormancy, or between bud break and shoot elongation. Oil use at these times can harm your tree. Horticultural oil can be used with caution as buds begin to swell and the tree enters the delayed dormant period. If your walnut tree is water stressed or suffering other forms of stress, do not apply oil. Oils should also never be used when temperatures are above 90°F. Scale infestations are on the rise. This is believed to be the result of several different factors, including reduced numbers of beneficial insects. Keeping your trees healthy makes them less likely to be harmed by pests such as walnut scale. Now you know. After investing time and garden space to asparagus, one of the last things you want to see is something attacking your spears. Originally from Europe, this tiny fly is now found everywhere asparagus grows. While asparagus miners do not cause serious damage, they can carry a disease that will. Asparagus miner description and lifecycle You won’t see the early life stages of asparagus miners. Whitish eggs are only 1/1000” in diameter and laid under the epidermis, at the base of asparagus stalks. Slightly larger larvae (15/1000”) are also white and tapered at both ends, with black mouth hooks. After feeding, they will grow to 1/5” in length before pupating. Pupae are dark brown and flattened and can be up to 17/100” long. These pests overwinter in the pupal stage, either in the soil or in stalks. Adult flies are small (1/10”), shiny black and somewhat humpbacked. They have clear, tapered wings. They appear most often in May and again near the end of the summer.
Damage caused by asparagus miners Damage is usually seen during the fern growth stage. As they feed, asparagus miners burrow a meandering pattern just below the surface. This feeding behavior can result in girdling, which causes chlorosis. More often, the damage is mostly cosmetic. The real problem associated with asparagus miners is that they are vectors for Fusarium root and crown rot. If you see bright yellow discoloration or wilting in your asparagus plants, it may be that asparagus miners have brought Fusarium root and crown rot to your asparagus bed. In that case, both the affected plant and the surrounding soil should be removed and thrown in the trash. Controlling asparagus miners Generally, parasitic wasps keep asparagus miners in check. If a heavy infestation occurs, remove the fern growth at the end of its season and throw it in the trash. Insecticides are not effective. Now you know. We’ve all heard about ladybugs, but what about twicestabbed lady beetles? Common ladybugs, or lady beetles, have the classic red half-domed shape, stubby antennae, and multiple black spots. This particular lady beetle has a black domed shape with two distinct red spots, hence the name. If you turn one over, their undersides are red or yellow. Twicestabbed lady beetle description
Twicestabbed lady beetles (Chilocorus orbus) are only one of four black lady beetles with red spots. The other three are Axion plagiatum, Chilocorus kuwanae, and ashy gray lady beetles. All four species are beneficial predators, so it isn’t critical to be able to tell them apart. [The ashy gray lady beetle has a unique ability to change its color from gray to red, but we will discuss that another day.] Twicestabbed lady beetle larva have the same bristled, elongated, alligator shape of other lady beetle larvae, but are more gray than black. Adults are 1/10 to 15 of an inch long. Twicestabbed lady beetle diet Twicestabbed lady beetles feed predominantly on adults and larvae of scale insects. Their diet includes armored scale on avocados, brown soft scale on citrus, European fruit lecanium on cherry, San Jose scale on pear, and more. You will rarely see twicestabbed lady beetle larvae because they spend most of their time hidden under scale insect domes, feeding. Eggs are even less likely to be seen, at 1/32” in length. Eggs may be laid singly or in clusters. Feeding is normally done by piercing the victim and sucking out their innards. Older lady beetles also bite and chew their food. As with other lady beetle species, it does no real good to buy them. If they don’t like what’s on the menu in your garden, they will simply fly away. If you make your garden appealing to lady beetles, they will find you. This means providing fresh, mosquito larvae-free water. [Use mosquito dunks in all standing water.] Lady bugs also eat pollen, so planting a variety of flower colors and shapes may attract them. Allowing dill, cilantro, and fennel to go to seed provides a ready food source for both you and lady beetles. Also, avoid the use of broad spectrum pesticides and insecticides. How many different species of lady beetles are in your garden? Brown soft scale (Coccus hesperidum) may be found on pomegranate and citrus trees, as well as bay laurel.
Brown soft scale lifecycle
Brown soft scale females give live birth, or lay eggs which hatch almost immediately. These young crawlers move around freely on leaves and twigs, feeding as they go. They continue moving around until they are about half grown, molting twice. Controlling brown soft scale Sticky barriers around the trunks of susceptible trees can cut off protection to brown soft scale pests by ants. Also, avoiding the use of broad spectrum pesticides allows natural predators to feed on these pests. If you see scale shells with holes in the top of them, you will know they have been parasitized by beneficial insects. Heavy infestations can be treated with dormant oil in winter, but this is rarely necessary. No, it's not a flying snake. Introducing another beneficial insect on the garden scene: the snakefly. I don’t know why they call it a snakefly. It doesn’t look like a fly or a snake. Apparently, snakeflies are native to the western half of North America, as well as Europe and Asia. Until yesterday, I had never heard of snakeflies. Let’s see what we can find out! The first thing I learned about snakeflies is that they are considered living fossils, having remained relatively unchanged for over 140 million years. Snakefly description Snakeflies (Agulla adnixa) have long, thin bodies with lifted torsos (prothorax), large eyes, extended mouthparts (mandibles), relatively long antennae, and a long, thin backend. Adults are reddish brown and can be 1/2 to 1” long. All four wings are transparent, and longer than the body, similar to lacewings (except that snakefly wings are covered with black veins). The long backend is not a stinger. Instead, it is an ovipositor, or egg-laying tube. Larvae have squishy bodies, and the head and first segment are hardened (sclerotised), but they look like a cross between an earwig and a ladybug larvae. [Sorry, but I couldn't find any free-to-use photos.] Snakefly larvae have 3 pairs of true legs, and, you won’t believe this: Snakeflies have an adhesive strip on their abdomens that allows them to move up walls and trees!
Snakefly lifecycle Eggs are deposited in the soil, where they are able to absorb soil nutrients to help them grow and develop. When they hatch, larvae stay in the soil or move to the bark of nearby trees. There, they feed on soft-bodied pests, such as grubs and caterpillars, as well as the eggs and larvae of many garden pests. Snakefly larvae go through as many as 10 moltings before reaching adulthood. This process can take 2 to 6 years. Next, after temperatures reach 32°F, the larvae enter a pupal stage. Unlike other insects, the snakefly pupa is mobile, leaving its pupal cell for day trips or to relocate. The pupal stage is temperature dependent, lasts a few days to 3 weeks, upwards of 10 months. [This is one long lived insect!] Adults snakeflies are very territorial as they feed on insects, such as mites and aphids. [Yay!] It is also believed that they occasionally nibble on pollen. Snakeflies court one another with cleaning rituals. You may see them practicing their flirting skills by cleaning their legs and antennae when alone. Have you seen any snakeflies in your garden? To me, they look almost Edwardian. Calendula officinalis is an edible flower that can add color and attract honey bees to your garden. Believed to be native to Europe, Calendula officinalis has been grown by people for so long and in so many locations, it is hard to tell for sure.
Pot marigold description Unlike the Tagetes genus of marigold, which have leaves that appear alternately along a stem, pot marigolds have slightly hairy leaves that are arranged in a spiral around the stem. They are short-lived perennials, typically grown as annuals, that grow 18 to 30” tall, with 2” flowers. Flowers are bright yellow or orangish-yellow, with ray florets and disk florets, common to sunflowers. Pot marigold’s curved seeds are actually dried fruits, called achenes. Pot marigold as an attractant In addition to looking lovely as a border plant, or in a parterre, Calendula officinalis will attract important pollinators, such as honey bees to the garden. Unfortunately, they will also attract cabbageworm butterflies, large yellow underwings, an invasive moth of the cutworm variety, and setaceous Hebrew character moths, whose larvae feed on a number of popular garden plants. Pot marigolds as food Pot marigold flower petals have a tangy, peppery flavor. Traditionally added to German soups and stews, pot marigold is also added to herb butters and cheeses, or chopped and used to garnish deviled or scrambled eggs, fish dishes, or steamed vegetables. Pot marigold flower petals add color and tang to salads. If you add marigold flower petals to rice, while cooking, the rice will turn yellow. For this reason, it is also known as Poor Man’s Saffron. Farmers have fed marigolds to chickens for years to make the yolks a deeper yellow. One variety of pot marigold, ‘Mexican Mint’, has the flavor of tarragon. It is also known as Texas tarragon. Pot marigold petals also make a delightful tea. Pot marigolds as medicine Pot marigolds also have medical merit. Research has shown that tinctures of pot marigold are used today to treat skin irritations and burns, to speed healing, and to control bleeding. [I wonder how they would look growing next to some aloe vera - just to keep the medicinals together.] This is not my area of expertise, and I won’t make any personal claims, but it is interesting to see how, every once in a while, those old treatments hold true. That being said, some people are allergic to pot marigolds. How to grow pot marigolds Pot marigolds are easy to grow from seed and they tend to be drought tolerant. Start seeds in small pots, only lightly covered with soil. Keep the soil moist, but not soggy, until germination occurs. Then, move plants to a sunny location with good drainage. Calendula may need protection from scorching summer afternoon sun, and they can be grown in containers, or on windowsills. Marigolds readily self-seed. Calendula pests and diseases While these plants are relatively trouble-free, they may become infected with powdery mildew, root rot, and smut. They are also susceptible to Alternaria leaf spot, aster yellows, charcoal root rot, cottony rot, cucumber mosaic, gray mold, Pythium root rot, root knot nematodes, rust, southern blight, spotted wilt (from the tomato spotted wilt virus), stem rot, and Verticillium wilt. I couldn't find any pests that significantly bother pot marigolds. Many of these diseases can be prevented by providing good drainage and air flow, so top dress soil regularly with organic matter, space plants with mature sizes in mind, and avoid overhead watering. So, do you know if your marigolds are edible or not now? This poem may help:
Psyllids are jumping plant lice that suck plant juices. Most native psyllid species do not pose a threat to your garden. Local predators tend to keep those populations in check most of the time. Invasive psyllid species are something else altogether. Psyllid identification Psyllids look like tiny cicadas or winged aphids with tubular mouthparts. They have powerful legs and short antennae. Psyllids can be 1/12 to 1/5” long. Adults hold their wings in a roofline position. Nymphs are flattened and look a lot like soft scale insects. Psyllid nymphs commonly produce waxy filaments or covers called lerps using wax and honeydew. Psyllid lifecycle
Regardless of the species, psyllids start as tiny eggs that hatch and go through five developmental stages or instars. Adult psyllids can fly, but most prefer to jump. If you think you see a psyllid run or fly, it is probably a psocid [SO-sid]. Psocids are beneficial insects that feed on fungi. They have a narrow “neck” and chewing mouthparts. Psyllid host plants As a species, psyllids have strong preferences for particular host plants. While some psyllids will prefer your sweet peppers and chilis, others will go after your peaches and nectarines, others will only feed on olive or pear trees, and other psyllid species will only feed on potato and tomato plants. The invasive Asian citrus psyllid carries huanglongbing,, a deadly citrus disease. Citrus trees infected with huanglongbing must be destroyed and removed by a professional arborist, which is both sad and expensive. These pests, when present, are most active in spring. Psyllid species most likely to threaten your garden include:
Dozens of psyllid species infest ornamental trees and shrubs, as well. These include the recent invasions of Ficus leaf-rolling psyllids and spotted gum psyllids. On the other hand, some psyllid species are beneficial. The Australian melaleuca psyllid, for example, has been purposefully introduced to Florida to help control paperbark trees, an invasive weed tree. Damage caused by psyllids One of the biggest problems associated with psyllids is their poop. After they have robbed your plants of valuable nutrients, they add insult to injury by excreting a large portion of the sap they ate and depositing it on leaves. Sap-sucker poo or honeydew is rich in sugar and other nutrients. Honeydew ends up being food for fungal sooty mold and disease-carrying ants. Psyllid feeding can also spread diseases, such as calico, and zebra chip, and disorders, such as galls, leaf and bud discoloration and deformation, and premature leaf drop. Leaf distortions often look similar to peach leaf curl. Pear psyllids inject fruit with toxins that blacken leaves and fruit skins. Psyllid feeding also creates points of entry for other pests and diseases. How to control psyllids in the garden Control psyllids with insecticidal soaps and yellow sticky sheets. Do not use dish soap. Parasitic wasps and pirate bugs feed on psyllids, so avoid using broad-spectrum insecticides. Severely infested plants should be removed and destroyed or thrown in the trash. Usually, simply monitoring plants can make controlling these and other pests much easier. To prevent invasive psyllids from finding your garden, only buy pest-free plants from reputable nurseries, and place new plants in quarantine. |
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