Grapes and pomegranates are under attack by grape mealybugs.

Conifer seed bug lifecycle

Adult female conifer seed bugs lay 200 eggs in rows, usually along needles, leaf midribs, or stems of host plants. In spring, the eggs hatch and nymphs go through five developmental stages, or instars, before reaching adulthood. In North America, there is only one generation a year, but two or more generations have been seen in Mexico and southern Europe.


Insecticides are not recommended, though they can be used as a last resort against heavy nymph infestations. It is better to avoid using broad spectrum insecticides. Provide pollen and water for natural predators. Some tachinid flies have been known to parasitize conifer seed bug eggs. Spiders, assassin bugs, and birds also feed on conifer seed bugs.

The fungi responsible for take all disease, Gaeumannomyces graminis, is found in the soil. It enters young plant roots and can often be seen as dying patches in a lawn or field.


Take all disease symptoms

The fungus enters the xylem and blocks the flow of water, causing stunting, yellowing, and reduced tillering. Tillering refers to the way lateral shoots emerge from the base of the stem, a common growth style of cereals. Infected plants mature faster than normal and have bleached seed heads and blackened roots and crowns.


Preventing take all disease

There are no effective chemical treatments against take all disease available to gardeners. There is a seed treatment that shows promise, so be sure to get certified disease-free seeds from reputable suppliers. Excessive liming and nutrient imbalances exacerbate this disease. If take all disease appears in your lawn, there isn’t much you can do besides improving drainage. If it appears in your barley, corn, millet, rice, sorghum, triticale, or wheat, the best thing you can do is rotate crops. Oats and rye, while cereal grains, are not susceptible to take all disease. 


Take all disease can build up in the soil, particularly in monoculture crops that are grown in the same place year after year. ​

There is one soil amoeba that feeds on the take all disease fungi. This unique protozoa is a type of vampyrellid. Vampyrellids are affectionately known as soil vampires because of the way they leave puncture marks in their victims.

Sunblotch control

Once a tree is infected with sunblotch, it must be removed and destroyed. This means that prevention is your only real course of action. Sunblotch can be transmitted through infected pollen, seeds, and budwood. You can’t do anything about infected pollen if the source is on someone else’s property, but you can invest in disease-free bare root trees. You can also make sure that any grafting projects you take on involve only healthy trees. And be sure to sanitize your garden tools after working on potentially infected trees with bathroom cleaner or a 9:1 ratio of water to bleach.

European fruit lecanium scale might be a long name, but these garden pests can make short work of your pomegranates, citrus, and olives.

European fruit lecanium scale description

European fruit lecanium scale is a soft scale insect. This means the shiny brown convex cover is not as hard as armored scale covers. You can identify European fruit lecanium scales because the brown cover has several ridges on it, while other soft scale insects do not. 


European fruit lecanium scale lifecycle

European fruit lecanium scale larvae are normally found on twigs and small branches. As temperatures begin to rise in spring, they develop the telltale dome-shaped cover. Adult females fill the space under their cover with eggs and then they die. When the eggs hatch, the nymphs, or crawlers, come out from underneath the scale covers and hide out on the underside of leaves. By late July or August, these pests migrate to fruit. There can be two generations each year and most of the insects present will be in the same life stage.


Damage caused by European fruit lecanium scale

When European fruit lecanium scale larvae feed, they attach themselves to the outside of twigs and fruit and pierce the surface. This causes cosmetic damage as well as providing points of entry for other pests and diseases. Also, European fruit lecanium scale feeding results in the excretion of honeydew (sugary bug poop), which sooty mold fungus finds delightful. The only exception is that scale feeding on pomegranates does not result in honeydew deposits. Instead, tiny piles of sugar are seen. These sugar piles are easily brushed off of twigs and fruit.


European fruit lecanium scale controls

Natural enemies are the best controls for European fruit lecanium scale. Twicestabbed lady beetles, steel blue lady beetles, and lacewings will all help fight soft scales. You can also wrap tree trunks with sticky barriers to remove the protection (and disease-carrying potential) provided by ants. 


Finally, prune trees for good air flow and structure to keep trees healthy.


European fruit lecanium scale (IPM Images) CC BY-SA 3.0 https://species-id.net/openmedia/File:Parthenolecanium_corni_IPM2168085.jpg

​Adult cigarette beetles only live for 2 to 6 weeks and they do not eat. They can fly, however. And cigarette beetle larvae are surprisingly destructive.

Cigarette beetles (Lasioderma serricorne) favor tobacco, but they can also damage your cereal grains,  and oilseeds, such as olive, peanut, soybean, and sunflower. Cigarette beetles will also feed on dried fruit, herbs and spices, such as paprika, cumin, and sage, flour, pet food, and your favorite books, given the chance.



Cigarette beetle description

These tiny brown beetles look almost identical to drugstore beetles and furniture beetles, with a more humpbacked profile. If you look very closely, using a hand lens, you can see that cigarette beetles have a distinctive club at the end of their antennae. ​

Cigarette beetles are tiny. Eight of them could stand, end-to-end, across a dime. But don’t let their diminutive size fool you. 


Cigarette beetle lifecycle

Adult female cigarette beetles lay 30 to 100 eggs in and around preferred foods. As soon as the larvae hatch, they start feeding and moving around. After feeding and pooping, larvae enter a pupal stage in cocoons made from the foods they infested, making them difficult to see.


While insecticides are effective against cigarette beetles, you are better off tossing out infested materials. Vacuuming and pheromone traps can also help control these tiny pests.

Plum pox symptoms

There are multiple strains of the plum pox virus, but the results are always unfortunate for stone fruit trees. Identifying this disease can be tricky. In some cases, the symptoms can be very subtle. They can vary by virus strain and host cultivar.  Generally speaking, leaf veins turn yellow and light green or yellow rings may appear on leaves, fruits, and pits. These symptoms may disappear during the heat of summer, only to return in autumn. Leaves may also exhibit crinkling, curling, and puckering. Cultivars with large, showy flowers may become variegated. Fruit may be deformed, turn brown, or develop concentric colored rings. premature fruit drop may also occur.


Unfortunately, these symptoms do not usually appear until the infection has been present for 2 or 3 years. During this time, several other nearby trees can easily become infected.


Plum pox transmission

The plum pox virus can travel long distances on infected plant material and insects. Grafting infected scions can transfer the infection to healthy trees. Several aphid species can carry this virus. 


How to avoid plum pox

If you only buy certified disease-free bare root stock and other fruit and nut trees, odds are pretty good that plum pox will not find your garden {assuming you don’t live where plum pox is already a problem). Placing new plants in quarantine and doing the best you can to control aphids will also help prevent this disease. Efforts are underway to develop resistant cultivars, but those trees are not yet available.


Plum pox may not kill fruit trees, but it can reduce production so much that you will probably end up replacing the trees anyway. Infected trees often produce fruit that is misshapen and more acidic than healthy fruits.


If you suspect plum pox, please contact your local County Extension Office or Department of Agriculture immediately.

Mid to late summer, spores of this fungal disease infect red and purple raspberries. Unlike yellow rust, which produces yellow to orange pustules in early to mid-summer, late leaf rust pustules are generally not seen until mid to late summer.


Late leaf rust symptoms

​The first symptom of late leaf rust (Pucciniastrum americanum) is small yellow (chlorotic) spots on the top of older leaves. These spots generally start to appear in lower portions of the plant, slowly spreading upward, into younger leaves. As the disease progresses, reproductive uredinia form on the underside of leaves, containing masses of spores. ​

Late leaf rust lifecycle

Spores of this disease overwinter in white spruce and infected raspberry canes. Spores can also be spread by wind, so the health of your upwind neighbor’s raspberries can have a direct impact on yours.


Late leaf rust control

Like other rusts, late leaf rust is best avoided by pruning plants for good airflow and avoiding overhead watering. Also, be sure to remove spent canes each year. If any of those canes have been infected, removing them will break the disease triangle.


​Fixed copper sprays may help prevent and treat late leaf rust.

Fig mites (Eriophyes ficus, also known as Aceria fici) are a type of eriophyid mite and they are found worldwide.


Fig mite description

Adult fig mites are pale yellow, wedge-shaped, and have two pairs of legs near the head, but they are extremely small. Even with a 20x hand lens, these mites are difficult to see. Larvae look something like a fat plant hair that moves. At only 1/250” long, the only way you will know they are present is by using a microscope or looking for signs of the damage they cause.


Damage caused by fig mites

Fig mites often infest young leaves and bud scales. Fig mite feeding causes russeting, most commonly seen on the underside of leaves and on the bottom of figs. Russetting transforms smooth, healthy tissue into rough, brown, dry tissue. Fig mite feeding also results in fruit and leaf drop and twig stunting. The real problem with fig mites is that they can carry and transmit fig mosaic. Trees infected with fig mosaic should be removed, so it is worth the effort.


Fig mite control

Monitor leaves for signs of mite feeding from late spring through summer. If fig mites are seen, apply sulfur or horticultural oils, depending on the time of year. [Oils can burn leaves in summer.]
 I have also seen anecdotal recommendations for the use of spinosad against fig mites, but I do not know how effective it is.

Unlike slow wilts caused by lack of water (or too much water), or vascular diseases, such as Verticillium wilt and Fusarium wilt, sometimes the leaves of melon, cucumber, pumpkin, cantaloupes, and other cucurbits and cotton suddenly and completely droop. This sounds like sudden wilt.


Sudden wilt is a soil borne fungal disease that occurs after heavy irrigation on hot, sunny days. Contrary to what you might expect, moisture-saturated soil combined with hot sun can cause sudden wilt, also known as parawilt. This is a result of the imbalance between water uptake and water loss, combined with certain fungi.


Sudden wilt symptoms

Sudden wilt starts out as yellowing of the crown leaves, followed by total collapse of the entire plant. Death soon follows. If you dig up an affected plant, the roots will be straw-colored or darker than normal. There are three different fungi responsible for sudden wilt and each one has unique symptoms:

• Pythium spp. - appears as brown root rot
• Acremonium cucurbitacearum - corky bands on discolored roots
• Rhizopycnis vagum - upper portions of the taproot turn reddish and corky

Sudden wilt treatments

There are no chemical controls against sudden wilt. Careful water management, proper plant spacing, and the removal of crop residue after harvest can help reduce the chance of sudden wilt occurring in your garden. Monitor your cucurbits for signs of sudden wilt near the end of the growing season. Good drainage and 2- to 3-year crop rotations can help prevent this disease from wiping out your cucurbit crops, and be sure to allow the soil to dry out completely between waterings.

Cucumber green mottle mosaic is a viral disease that can take a big bite out of cucumber, watermelon, and other melon crops. ​

This cucurbit disease is found on infected seeds and there is no known cure. It was first seen in the U.S. in 2013. Prior to that, it was only seen in Russia, China, Japan, Korea, India, Spain, and Israel. It is believed to have been brought to the U.S. on infected seed.


Cucumber green mottle mosaic symptoms

Cucumber green mottle mosaic enters plants through wounds and root-to-root contact. Symptoms of cucumber green mottle mosaic (CGMMV) are subtle. At first, infected plants may look fine. Then you may see light yellow spots on young leaves, vein clearing, or chlorotic mottling. Leaves may also become deformed. Stunting and leaf death are more commonly seen in older plants. As leaves mature, the symptoms seem to disappear, providing a false sense of security. 


By the time the disease is full-blown, it still doesn’t look terrible. The problem is, this disease causes fruit drop and reduced fruit size. Crops can be reduced by 25 to 80%. Fruit that makes it to harvestable size can also have a mottled appearance and the interior is often damaged and inedible.


Cucumber green mottle mosaic control

Since there is no cure for this contagious disease, infected plants must be removed completely, along with a few of their neighbors, to prevent it from spreading. Using certified disease-free seed and placing new plants in quarantine can help prevent this disease from infecting your soil. Since this virus can also be transported on tools, shoes, and clothing, good sanitation practices can also protect your plants.

Ten-lined June beetle controls

Heavily infested trees must be removed and the surrounding soil fumigated to prevent infestation of nearby trees. Luckily, that is rarely necessary in a home garden. Because female ten-lined beetles do not fly, populations spread slowly. Commercial growers use soil insecticides to kill beetles in the larval stage. Aboveground insecticides are not effective. 


Tachinid flies parasitize these pests, but not significantly. Because male ten-lined June beetles are attracted to light, you can capture them on your porch with a butterfly net and feed them to your chickens, or simply squish them whenever you see them.

Bulb mite description

Bulb mites are a collection of pests from the Rhizoglyphus and Tyrophagus genus and they look like miniature ticks with spiky hairs. These pests may be tiny, but they can cause significant damage. Ranging in size from 1/2 to 1 mm long, you could 15 to 30 or more of them nose-to-tail across a dime. If you were to look at one with a magnifying glass, you would see that they are a shiny, creamy white, with four pairs of brown legs.


Bulb mite host plants

As the name implies, bulb mites infest bulbs, such as tulips, daffodils, and saffron crocus. They can also be found under the root plate of garlic and onion, or in the crown of spinach plants.


Damage caused by bud mites

Bud mite feeding is not particularly destructive by itself. The problem lies in the wounds created by that feeding. These damaged areas allow organisms responsible for decomposition to get inside your plants, causing them to rot. Overall stunting, leaf distortion, and softened stems are common responses to bud mite feeding.


How to manage bulb mites

Protect your bulbs against bulb mites by inspecting them before planting. Infested bulbs should be destroyed. Crop rotation and the removal of post-harvest plant debris can interrupt this pest’s lifecycle.

Like its cousin, the bright orange rust seen on the underside of rose leaves, yellow rust is a fungal disease. Unlike many other fungal diseases, this rust only occurs on the outside of plants. This is not the same yellow rust seen on wheat, rye, and barley, which is called stripe rust. Stripe rust is caused by Puccinia striiformis. 


Symptoms of yellow rust

Plants infected with yellow rust (Phragmidium rubi-idaei) will initially have yellow pustules, called aecia, on the tops of the lower leaves. These symptoms are usually only seen in spring and early summer. In early to mid-summer, yellow to orange pustules, called uredinia, are found on the underside of leaves. As summer progresses, these growths darken and a black spot can be seen in the middle, if you look closely. You may also see orange spots on the fruit. Similar infections that occur later in the season may be late leaf rust (Pucciniastrum americanum), or the more severe orange rust (Arthuriomyces peckianus). In any case, infected leaves wither and die, reducing the plant's ability to perform photosynthesis. This can reduce crop size significantly.


Yellow rust control

Pruning for good air flow helps leaves and stems dry out, making life more difficult for this fungi. Since yellow rust spores (teliospores) overwinter in fruiting canes, or floricanes, pruning those canes out at the end of the growing season can break this disease triangle. The canes of summer-bearing raspberries won’t produce any more fruit anyway, so you might as well. Just be sure to dispose of the trimmed canes in the trash, and not the compost pile.


Left in place, these spores then spread the infection to the next season’s primocanes, or vegetative growth. Also, keep the area around the plants clear of dead leaves and other plant debris. If your raspberries are especially prone to yellow rust, you may want to cut the first spring growth of new canes back to ground level. Don’t worry, the root system will put out new canes pretty quickly. That first growth is the most likely to have become infected.


Fixed copper sprays and lime sulfur are recommended for severe outbreaks. Otherwise, you can simply remove infected leaves by hand and improve the air flow between plants to keep this disease in check and protect your delicious raspberries.


Resistant varieties are available, so check with your local Department of Agriculture or Master Gardeners for recommendations for your area.

Symptoms of pea seed-borne mosaic

Stunting, deformation, and rosette-type growths at the ends of stems are all signs of pea seed-borne mosaic. Chlorosis, downward cupping, vein clearing and swelling, and the classic mosaic or mottling of mosaic diseases may all be present in infected plants. Vein clearing is a common symptom of viral infections and it refers to the way leaf veins appear translucent. Seeds tend to be shriveled and discolored. Infected plants are slow to reach maturity, but don’t leave them in the ground long enough to notice. Pea seed-borne mosaic infection is easily mistaken for chemical overspray, nutrient toxicities, and water-stress. Laboratory tests are needed to be sure of infection. You can often take zip-lock bagged samples to your local Department of Agriculture for analysis.


How to control pea seed-borne mosaic
​
The pea seed-borne mosaic virus (PSbMV) is carried to your garden on aphids. I would tell you to control the aphids, but that is an ongoing battle in the garden. Do the best that you can. Plants infected with pea seed-borne mosaic should be removed immediately. Unfortunately, some infected plants will never show symptoms. As aphids feed on these asymptomatic plants, they then carry the disease to nearby plants, spreading infection. For the most part, as the name implies, this viral disease is carried by infected seeds. Plant infected seeds and the aphids do the rest. To prevent pea seed-borne mosaic from occurring in your garden, only buy clean, disease-free seeds. 


This disease can overwinter in nearby weeds, such as shepherd’s purse, vetches, and black medic. It can also be carried on alfalfa and sugar beets without causing the host plants any problems. If you notice outbreaks of pea seed-borne mosaic, and you know your seeds were clean, look at what is growing nearby.


You can prevent pea seed-borne mosaic by planting resistant varieties.

How fig mosaic is spread

Fig mosaic is spread by eriophyid mites, particularly fig mites. As the mites feed, the virus is transmitted through their saliva. Fig mosaic can also be spread by grafting and cuttings.

Fig mosaic management

Tree infected with fig mosaic should be removed. Trees take time to grow, so having to remove an infected tree is best avoided. Begin by only installing disease-free tree and planting them at the proper depth, giving them the irrigation and food they need to stay healthy. Monitor your fig trees for sign of mite feeding. You will need a 20x hand lens to see these tiny sap-suckers. Fig mite feeding is usually seen around bud scales and young leaves and it often causes a faint russetting. Twig stunting and leaf drop may also occur.


Sulfur treatments and horticultural oils have been shown to control fig mites. 


Go take a look at your fig tree to see if mites might be present. If they are, get rid of them so that you can enjoy many years of sweet, delicious figs.

Squash mosaic carriers

​Unlike other mosaic diseases, squash mosaic is not spread by aphids. Instead, striped and spotted cucumber beetles, leaf beetles, and 28-spotted ladybird beetles are the most common vectors of squash mosaic. Many other beetles are also capable of hosting the virus. As these insects feed, their saliva transfers the virus to the plant. This is why it is so important to remove infected plants right away.


Squash mosaic controls

In addition to removing infected plants, beetle control is important in the prevention of squash mosaic. And beetles can be tough to control. The virus can stay viable inside a beetle for up to 20 days, so it is worth the effort. A single beetle can infect dozens of plants in that time frame. To control beetles, handpicking is always an option, if you are quick enough. You can also use neem oil to kill beetle eggs. Encouraging beneficial predators, such as ladybugs, mantids, and solider bugs, in the garden with fresh water, insectary plants, and little or no chemical use is probably the easiest method of keeping beetle populations within reasonable limits.


Squash mosaic can also be carried on melon seeds, so be sure to get clean, disease-resistant seeds from a reputable supplier (and not that melon from the grocery store).


Certain chenopod weeds, including lambsquarters, goosefoot, Russian thistle, and kochia, provide overwintering sites, so keep these weeds away from your cucurbits.


As with many other viruses, tools, clothing, and other surfaces can also become carriers. To prevent the spread of this disease, sanitize tools regularly and avoid working around plants while they are wet.

Zucchini yellow mosaic host plants

In addition to infecting zucchini, zucchini yellow mosaic also infects other members of the cucurbit family, including melons, squash, pumpkins, some gourds, cucumbers, cantaloupe, and watermelon. The disease is transmitted by aphids.


Zucchini yellow mosaic management

As anyone who gardens knows, controlling aphids is difficult. These pests seem to appear overnight, in huge numbers. And all it takes is one aphid to get the whole process started. Unfortunately, insecticides are rarely useful in managing zucchini yellow mosaic, because the disease has often been transmitted before you even know the aphids are there. Reflective mulches can be used to discourage aphids, just be sure to remove the reflective material before it gets too hot. Row covers can also be used to reduce access to susceptible plants.


This disease can also be spread on infected garden tools and seeds, so be sure to sanitize your tools regularly and get your seeds from a reputable source (and not that zucchini from the grocery store).


Infected plants should be destroyed and replaced with resistant cultivars.


Since this virus is only viable for a few hours within their aphid carriers, creating a physical barrier of tall, non-host plants around your cucurbits can be enough to prevent the aphids from getting to the plants while the virus is still active.

Mosaic diseases are caused by a variety of viruses that can infect the majority of your garden plants. Since these diseases are difficult or impossible to treat, recognizing and removing infected plants right away can help prevent the disease from spreading.


Symptoms of mosaic diseases

The classic mottled appearance of infected leaves is only one symptom of mosaic disease. Leaf cupping, blistering, stunting, crinkling, and other distortions are also common symptoms of mosaic disease. Stems may be shortened, creating a bushy appearance to vines. 


Plants infected early in the growing season rarely produce fruit. Interestingly, plants infected later in the season retain their healthy, earlier growth and fruit production, while future growth is distorted. Fruit may also show the same mottling and other distortions seen on leaves. Warty bumps are common.

Common mosaic diseases

While there are dozens (hundreds?) of mosaic diseases, some of the more common varieties include:

• bean common mosaic
• bean mosaic
• bean yellow mosaic
• cucumber mosaic
• fig mosaic
• pea seedborne mosaic
• squash mosaic
• tobacco mosaic
• watermelon mosaic
• zucchini yellow mosaic

Mosaic disease management

Generally speaking, mosaic diseases are not curable. Infected plants should be removed. This means that prevention is a far better course of action. 


Depending on the specific virus, it may be carried in to your garden on seeds or tools, or by aphids, dryberry mites, and any number of other sap-sucking pests. Removing weeds that could provide overwintering sites, creating physical barriers with row covers and walls of non-host plants, and regularly sanitizing your tools goes a long way toward preventing mosaic disease from taking hold in your garden, as does buying clean, disease-resistant seeds and plants from reputable suppliers.


While mosaic diseases make plants look funny, the fruit of infected plants is still safe to eat. The viruses responsible for mosaic diseases are not harmful to people.

Corn stunt does not mean ears of corn will suddenly start doing gymnastics over the fence into your neighbor’s yard. Instead, this bacterial disease will infect the phloem of corn plants, reducing them in size and all but eliminating kernel production.


Corn stunt disease complex

Some people see corn stunt as a single disease, while others see it as one part of a complex of three disease, the other two being maize bushy stunt mycoplasma and maize rayado fino virus (MRFV). Yet others include maize chlorotic dwarf virus in the corn stunt complex. Any combination of these diseases can be devastating to your corn crop.


Corn stunt symptoms

Healthy corn plants produce one or two ears of corn, depending on whether they are early or late maturing varieties, respectively. Plants infected with corn stunt are significantly shorter than normal, often only 5 feet tall, and may produce 6 or 7 ears. That may sound great, but it’s not. These ears are small and they do not fill properly, meaning there ends up being a lot of empty spaces. The kernels that do develop are not well attached, in a condition known as “loose tooth ears”. Infected plants will also exhibit pale yellow new leaves at the top. As these leaves mature, they tend to turn reddish.


How corn stunt spreads

Corn stunt is caused by Spiroplasma kunkeliiI, which is carried by leafhoppers. Corn leafhoppers (Dalbulus maidis), in particular, carry this disease with them, spreading it as they feed.


Corn stunt management

You can prevent corn stunt by using reflective mulches that deter leafhoppers. Planting your corn as early as possible in the growing season has been shown to reduce the impact of corn stunt infections. Apparently, the first generation of emerging bacterium are not as effective at spreading the disease as those that occur later in the season. Insecticides are generally not effective.