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.

Apium virus Y disease symptoms

Leaf mottling or mosaic patterns, stunting, cleared veins, and leaf distortions are all symptoms of apium virus Y disease. Older leaves may have yellow blotches, brown lesions, and yellow or brown line patterns. Younger leaves show only faint mottling. Lesions may form on petioles (leaf stems).


How to prevent apium virus Y disease
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Since this disease is predominantly carried by aphids, you can help prevent this disease by controlling aphid populations (as much as is possible, of course). The virus can also be carried on clothing and tools, so be sure to sanitize your tools regularly and avoid walking through areas known to be infected. The virus does not remain vital for very long once it is inside an aphid. Creating physical barriers and increasing the distance between potential carriers can reduce the likelihood of this disease.


Crop rotation and the CAREFUL removal of poison hemlock can also help control this disease. There are no effective chemical treatments for apium virus Y disease.

Tree anatomy

Tree trunks are made up of several layers of tubes, surrounded by an outer layer of bark. These tubes are the vascular bundles that carry water and nutrients to the rest of the tree. One type of tube, called the xylem (or sapwood), pulls water and nutrients up from the roots. The majority of the trunk is made up of xylem cells. Another type of tube, called the phloem (or inner bark) carries the sugars made by the leaves through photosynthesis down into the rest of the tree. [I remember these two by saying, “Food flows down the phloem, while water and food rise in the xylem.”]


Just between the xylem and the phloem is the cambium layer. This is where the actual tree growth occurs. At the very center of the tree is the pith, surrounded by layers of xylem cells. As these xylem cells age, they eventually go through chemical changes that make them solid, losing their ability to transport water and nutrients. There is debate about whether or not these cells are still alive. This is the heartwood.


Characteristics of heartwood

Heartwood is very strong. The amount of heartwood present depends on the species. Some trees, such as ash, maple, and pine, have very thick heartwood. Other species have only a little heartwood. This group includes chestnut, mulberry and sassafras trees. Some tree species have no heartwood at all.


Heartwood gets larger over time. Young trees have very little heartwood, whereas older trees have significantly more. 


Heartwood is resistant to decay, but wood that looks like heartwood might also be infected with disease or dealing with an insect invasion. Louisiana homes built over 100 years ago out of of bald cypress heartwood appear to be as good as new because of the decay resistance of heartwood.


The next time you need to remove a large branch or tree trunk, take a closer look at the layers and see if heartwood is present.

The word pectin comes to us from the Greek word for “congealed” and with good reason. Pectin converts liquids into jelly, much the way gelatin does, the difference being that gelatin is made from animal skin and bones, and pectin is made from plants.


Pectin is found in most fruits, to one degree or another:

• apples 1-1.5%
• apricots 1%
• cherries 0.4%
• oranges 0.5-3.5%
• citrus peels 30%

But fruits are not the only plants that contain pectin. Carrots hold an average 1.4% pectin. Commercially, most pectin is made from citrus peels and apple pulp. Soft fruits, such as grapes and strawberries also contain pectin, but at very low levels.


How do plants use pectin?

Pectin is a structural chain of molecules used in cell walls. Pectin is a major component of cellulose, specifically a layer called the middle lamella. The middle lamella is an outer layer to plant cells that is used to bind cells together. This allows plants to grow larger. The level of pectin present in a plant varies over time due to factors such as plant age and seasonal changes.


As fruits ripen, the pectin begins to break down, which is why the fruit becomes softer. A similar process occurs during abscission, when parts such as leaves naturally die and fall from the plant. In some desert plants, pectin has been shown to help repair DNA by creating a mucous layer that captures dew.


How do we use pectin?

Pectin is used for more than jelly making. Pectin also provides dietary fiber and it acts as a thickening agent and stabilizer for desserts, cosmetics, and medicines. Pectin also binds to cholesterol and slows the rate at which we absorb glucose. This is especially true when the pectin is from apples and oranges. You know that old saying about an apple a day? I guess they were right!


The pectin found in apple pulp is also one of the best throat lozenges I know. The mucilaginous pectin provides a surprising amount of soothing relief. Next time your have a sore or scratchy throat, skip the menthol (an irritant) and slowly eat an apple.

Symptoms of molybdenum deficiency

Without molybdenum, leaves turn yellow and die and flowers may fail to form at all. The yellowing is often along leaf margins and downward cupping may also appear. In some cases, leaves develop a whiptail shape, rather than the leaf’s normal wider blade shape. Corn kernels may germinate on the cob prematurely in a last-ditch effort at reproduction. Legumes will have fewer or no root nodules if molybdenum is in short supply.


Again, you don’t know what your plants have access to without an inexpensive, lab-based soil test. Take my word for it, it is worth the effort.

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.

What is a pod?

Pods are made from carpels. Carpels are the female reproductive organs of a plant. The pods of legumes are made from a single carpel, while members of the cabbage family produce pods made from two carpels that have been fused. The pods made from fused carpels are called silique.


Pods are a type of dehiscent fruit. Dehiscent means that the structure opens spontaneously when its contents are mature. If a pod does not open automatically, it is called indehiscent. In either case, pods are made up of two identical long halves and they contain seeds. Those halves are the outer walls of the ovary. The two halves are joined along a seam, called a suture. Held between those two halves is a ribbon of seed-bearing tissue called the septum.


Brassica pods

There are two categories of Brassica pods: siliqua and silicula. The difference between the two is simply the pod dimensions. If the length of the pod is more than three times the width, it is a silique. If the length is less than three times the width, it is a silicula (or silicle).


If you allow your radishes and other Brassicas to go to seed, you will see siliquae for yourself, plus you will have seeds for next year’s crop!

How hairy bittercress grows
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Found pretty much everywhere, hairy bittercress prefers moist soil, open ground, and freshly disturbed areas. Like other weeds, it grows rapidly, often having two generations each year. You may think they have disappeared during the heat of summer but the first autumn rain will let you know that they were merely waiting for wetter conditions. These plants have long taproots.

Hairy bittercress seeds are held in capsules, called siliquae. When the fruit within ripens, there are valves on the siliquae that create a tightly wound coil. That’s why, when you touch them, seeds  explode in every direction. This method of seed dispersal is called ballochory.


Problems with hairy bittercress

Once hairy bittercress takes hold on your property, you will be dealing with it more and more each year, for better or worse. Because of its ability to fling seeds near and far, and grow quickly, hairy bittercress often finds its way into your garden on nursery plants. It is far simpler to put new plants into quarantine and monitor for weed growth right along with pests and diseases.


Before you shrug off this seemingly minor weed, you need to know that the real problem with hairy bittercress is the fact that it can host some nasty diseases. Specifically, tomato spotted wilt and cucumber vein yellowing can be carried into your garden on hairy bittercress. These diseases can have a huge impact on several of your crops, and not just tomatoes and cucumbers.


It is far easier to monitor the ground each spring and autumn for tiny rosettes and then use your long weeding tool to get under the taproot before it takes hold.

How dish soap works

Dish soap, also known as dish washing liquid, is a detergent. Dish soap helps us get our dishes clean by cutting grease, oil, and wax. Dish soap generally contains colorants, fragrances, bleach, enzymes, phosphates, and rinsing agents.


Insects and plants have waxy coatings that are also damaged by dish soap. When this protective coating is removed, infection, pest infestation, and dehydration all become more likely.


Dish soap v. insecticidal soap

Insecticidal soap is not a detergent. It is a soap made specifically formulated for use on plants. And it must be used properly to be safe for plants and effective against pests. While liquid hand soap is a soap and not a detergent, it contains fatty acids which are phytotoxic, or poisonous, to plants.


Before trying a Quick Fix on your edible plants, take the time to research what is really going on. Your plants will thank you.

How to correct over-fertilization

Looking at the results of my 2019 soil test, I realized that I hadn’t done nearly enough to correct my over-fertilization problem and had wasted 4 years in the process. Now, to correct the problem, I have stopped using my nutrient-rich compost on the ground. Instead, I am saving it for raised beds and container plants until my over-fertilization problem has been corrected.


And that’’s the cure - stop adding nutrients. The other half of the cure for over-fertilization is to remove nutrients by taking plant material out of your yard completely. Instead of grasscycling, bag and remove grass clippings. Or, you can add them to the compost pile or feed them to your chickens. Avoid using the chop and drop method for a while. Plant more heavy feeders, such as asparagus, beans, beets, broccoli, Brussels sprouts, cabbage, carrots, celery, corn, cucumbers, eggplant, garlic, leeks, melons, okra, onions, parsnips, peas, peppers, potatoes, pumpkins, shallots, squash, tomatoes, and turnips. And harvest those crops to within an inch of their lives. Take everything they have to give and get it out of your yard.


Armed with the results from my more recent soil test, I am now adding far more iron, to help my plants absorb what they need, and using wood chip mulch to counteract the compacted soil, but these actions will take time to have an effect. To monitor the effectiveness of these new actions, applying more iron and removing more plant material, I will switch to annual soil tests until the over-fertilization problem has been resolved. 


I urge you to do the same.

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.

Cow parsnip description

True to its Latin name, Heracleum maximum, these are very large herbaceous plants. Reaching over 9’ in height, all parts of cow parsnip are big. Lobed leaves can be 16” across and the typical umbel-shaped flowers of the carrot family are also large, averaging 8” across. These flowers are white and the outer flowers are often larger than the inner flowers. Stems are succulent and sturdy. ​

This dangerous sap is found on coarse white hairs (trichomes) on stems. It can cause third-degree burns serious enough to land you in the hospital or a burn unit. Giant hogweed has found its way to northern U.S. states. If you see it, report it to your local County Extension Office.


Another toxic plant commonly mistaken for cow parsnip is poison hemlock, also with purple marks on the stem. Bottom line: when in doubt, don’t.


Since cow parsnip, giant hogweed, and poison hemlock can all hurt you, to one degree or another, it is a good idea to be cautious and wear protective clothing whenever you might be around them.

Cone and seed development

While male cones usually only last one year, it can take 3 or more years for a female cone to fully develop. Once a female cone is receptive and pollination has occurred, it can take up to a year for fertilization to be complete. As seeds develop, some cones will slowly begin to open, while other species need fire to trigger opening. Stone pine seeds, while delicious, require a lot of hard work to separate them from their cones.


Some conifer seeds have a wing that allows them to be carried on the wind, while other species rely on animals, such as squirrels, and birds help them disperse. Stone pine seeds, while delicious, require a lot of hard work to separate them from their cones.


Types of cones

The cones of holiday decoration fame are only one of many different types of cones. The scales can be arranged in one of two ways: imbricate or peltate. Imbricate scales overlap much like roof tiles and are attached along a common axis. Peltate scales do not overlap and are attached from a central point, more like an umbrella. Some cones look more like berries than cones.

     Araucariaceae (monkey-puzzle tree, kauri, and the nearly extinct Wollemia tree) - fused scales create a spherical cone; imbricate

Gypsum in the garden

Gypsum is made of calcium and sulfur, two nutrients important to plant health. In the early 1800’s, gypsum was considered such a fertilizer miracle that smugglers battled local authorities in what became known as the Plaster War. At that time, gypsum was also known as sulfate of lime or lime sulfate.


Plants use calcium to maintain cell walls.  Calcium in the soil helps build healthy soil structure by binding tiny clay particles into larger clumps called aggregates. Sulfur is an important component of proteins used by plants. As such, gypsum can be beneficial in the garden, but not always.


False claims about gypsum

Like most other quick fixes, many of the claims about gypsum are based in fact, but taken too far.

• Acidification - Normally, elemental sulfur is used to acidify soil as it reacts with water to form sulfuric acid. The sulfate ion in gypsum, however, does not turn into sulfuric acid, so it does not acidify the soil.
• Blossom end rot - this condition is not, as popularly thought, the result of insufficient calcium in the soil (which is extremely rare). More often, it is due to water stress. Adding gypsum will do nothing for your irrigation schedule.
• Drainage - Unless you have clay soil with high salt levels (see below), gypsum will not improve drainage.
• Soil fertility - Beside adding calcium and sulfur, which may or may not be needed, gypsum does nothing for overall soil fertility. Soil fertility is largely a function of its cation exchange capacity (CEC), pH, and organic matter content, not the presence of gypsum.

Applying gypsum unnecessarily can cause leaching of aluminum, iron, lead, manganese, potassium into local lakes, rivers, and underground water stores. It also interferes with the beneficial soil microorganisms responsible for helping plants absorb nutrients. Applying gypsum to sandy soils can slow the transport of copper, phosphorus, and zinc.


Benefits of gypsum

All that being said, there is one situation when gypsum can be helpful in the garden. This only occurs when clay soils contain high levels of salt or, more accurately, sodium. These sodic soils can benefit from gypsum applications, in moderation. High salt levels in clay compound poor drainage, often causing heavy crusts to form. Adding gypsum in this situation allows the calcium to bind to the clay, replacing the salt, which is then leached out of the soil over time through cation exchange. Ultimately, this improves soil structure and drainage and reduces salt levels. Adding gypsum to clay without high sodium levels is a bad idea, as it can make alkaline soils even more alkaline. In most cases, plants need a soil pH of 5.5 to 7.0 to thrive.


Rather than simply adding gypsum because you heard it was a good idea, get your soil tested, determine your soil structure, and mulch everything with coarse wood chips to improve your soil and help your plants grow.


If you happen to find a large, fine-grained seam of gypsum, you are in luck. Because that particular form of gypsum is more commonly known as alabaster. 


Now you know.

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.

Types of tropism

​Tropisms can be positive or negative. Positive tropisms attract the plant toward the trigger, while negative tropisms push the plant away. Sunlight is generally a positive tropism, causing plants to lean, turn, and pivot to follow its rays. In some cases, particularly darkened jungle floors, sunlight is a negative tropism, initially, driving vines to seek trees which they will later climb. ​

Tropisms are generally named for the stimuli:

• gravitropism - roots grow downward (positive tropism) and stems grow upward (negative tropism) in response to gravity; also known as geotropism
• heliotropism - pivoting movement that allows plants to follow the sun’s movement across the sky
• hydrotropism - the root cap senses water in the soil and grows toward it
• phototropism - stems grow upward, toward sunlight
• skototropism - vines move away from sunlight in order to find trees to climb
• thigmotropism - tendrils twine around supports

Plants also respond to chemicals (chemotropism), electric fields (electrotropism), magnetic fields (magnetotropism), oxygen levels (aerotropism), and temperatures (thermotropism)


The opposite of tropism

When a plant responds in a direction that is not determined by the position of the stimulus, it is called a nastic movement. Common nastic movement triggers include being touched or the way a flower opens and closes each day (nyctinasty). When being touched causes flowers or leaves to suddenly close themselves up in a specific and regular pattern, rather than the thigmotropism seen in climbing tendrils, it is a nastic movement. The location of the finger has nothing to do with the way the flower closes. In the latter case, the sun going down may trigger the flower to close, but the direction of that closing is not related to the sun’s position.


Plants may not be able to get up and walk around, but they have a unique arsenal of movement-related responses they can use to help themselves grow and thrive.


Which tropisms do you see in your garden?

Yellow jackets (or yellowjackets) are omnivorous social wasps and they can be a royal pain at outdoor summer events. Not only can yellow jackets be annoying, as they feed on your burgers and cupcakes, they can sting and bite at the same time! 


Unlike honey bees, which lose their stingers (and die) after a single sting, yellow jacket stingers do not have barbs and can be used repeatedly and with great prejudice. The more you know about yellow jackets, the better you can protect yourself and your family from painful stings.


Yellow jacket identification

Yellow jackets are frequently confused with bees and other wasps. Unlike stubby, brown honey bees, which are covered with short hairs, yellow jackets appear more smooth-bodied and shiny. Beneficial mud daubers have a very narrow waist and build their nests out of mud and paper wasps build small, umbrella-shaped nests with exposed cells. Mud daubers and paper wasps generally do not eat human food and are rarely aggressive unless provoked.
​

Seasonal wasp aggression

Yellow jackets are particularly aggressive when it comes to protecting their nest. Yellow jackets are also likely to sting while out foraging for food. The aggressiveness of yellow jackets changes with the seasons.


In spring, yellow jackets are busy building their nest and providing larvae with protein, usually in the form of insects. As summer progresses and the colony population increases, their need for protein decreases and sugary foods, needed by the queen and her workers, are in greater demand. This is also when many resources start becoming more scarce and wasp aggressiveness becomes more of a problem.


By late summer and autumn, yellow jackets are best described as angry scavengers. This is when they end up at your picnics and cookouts. They are also seen around pet food, trash cans, and around fruit trees, where overripe fruit provides easy access to sugar.