Aphids on potatoes? Well, why not? They’re on everything else!


Potatoes are susceptible to two different types of aphids: green peach aphids and potato aphids. Today, we will learn about potato aphids.

Originally from North America, these pests are now found everywhere potatoes are grown. And potatoes are not their only food of choice. Your cabbages, tomatoes, eggplant, peaches, and peppers are also at risk, along with many other food crops.


Potato aphid description

Potato aphids (Macrosiphum euphorbiae) can be either green or pink, with a dark dorsal stripe, and they tend to be larger, with longer legs, than most other aphid species.  When feeding on tomatoes, potato aphids become distinctly red. They have the same long-legged, soft, pear-shaped wingless body of other aphids. As populations boom, or food becomes otherwise scarce, some aphids will develop wings with which to fly to new feeding grounds.

Potato aphid lifecycle

Potato aphids, like other aphids, are phenomenally prolific. A single female aphid can produce 600 billion descendants in a single season. Aphids reproduce both sexually and asexually. When females produce offspring without male intervention (parthenogenesis), the offspring are born live and significantly smaller than their co-authored siblings. When reproduction involves a male counterpart, offspring are laid as eggs that overwinter in nearby weeds, or on other host plants. Adult aphids molt four times, leaving behind telltale white skins.


Damage caused by potato aphids

Aphid feeding is usually first seen as deformed leaves. As aphids feed, they damage plant tissue and disrupt the balance of growth hormones. This can reduce or eliminate crop size, and it can kill young plants. These sap sucking pests tend to cluster together, piercing plant tissue and sucking out nutrient rich fluids. They also poop out sugary honeydew, which attracts protective, disease-carrying ants, and creates habitat for sooty mold. 


Potato aphid feeding can certainly weaken plants, but the real problem is that these aphids carry and transmit a number of viral diseases, such as cucumber mosaic, lettuce mosaic, bearded iris mosaic, narcissus yellow stripe virus, tulip breaking virus, potato virus Y, beet mild yellowing virus, beet yellows virus, alfalfa mosaic, and potato leafroll disease. Plants infected with potato leafroll disease will produce potatoes with a network of browning phloem tissue, called net necrosis, that is very unappetizing. Once a potato plant is infected with leafroll, it and three plants in all directions should be removed to prevent further spread of the disease.


​Controlling potato aphids

The battle against aphids in the garden never ends. It starts by monitoring plants regularly for signs of infestation. Potato aphids tend to prefer the lower portions of plants, the undersides of leaves, and around new buds. You can dislodge aphids with a powerful stream of water from the garden hose, but it is practically impossible to get every single aphid off your potato plants in this way, and it only takes one aphid to start the whole process over again. Insecticidal soaps can be used with better results, but you have to make sure you wet every surface of the plant. Personally, I wipe them off whenever I see them. I like to think it slows them down a little, if nothing else.


The next step in controlling potato aphids is to remove nearby plants that might harbor these pests. This means keeping weeds away from potato patch. Malva, penny cress, and various mustards, in particular, can act as early season host plants for this pest. 


Luckily, lady beetles, lacewings, syrphid or hoverfly larvae, and parasitic wasps will all help control potato aphid populations. That’s assuming you haven’t used broad spectrum pesticides and wiped out your helpers. 


What's eating your potatoes?

Not counting gardeners, there are several types of mammals that may turn up in your garden. Some can be helpful, others can be a royal pain. ​

Mammals are warm-blooded and more or less intelligent. This can make excluding them from certain areas of the garden problematic. In most cases, there are ways to work around pesky mammals in the garden, without losing your mind or getting in trouble with local law enforcement.


Speaking of law enforcement, before you go trapping, shooting, poisoning, or otherwise dispatching wildlife, you need to track down your local laws and obey them. The low level squirrel feud can turn into a legal nightmare if improper methods are used against them. It’s not worth it - regardless of how tempting it may be when they take your last juicy pears for the umpteenth time!


So, let’s see which animals might end up in the garden and how to protect your plants against them. 


Bats

There are three major types of bats found in North America: leaf-nosed bats, vesper bats, and free-tailed bats. These bats are primarily insectivores, capturing insect pests, such as moths, wasps, flies, mosquitoes, in flight, or capturing beetles, ants, and other insects off of leaves or from the ground. This makes bats welcome guests in the garden, though they will sometimes eat ripe fruit. [Who can blame them?] You can attract bats to your garden for the evening shift by installing a bat house.

Deer

Deer are the bane of gardeners wherever they are found. These animals can leap small buildings in a single bound. Oh, wait, wrong story. But deer can wipe out an orchard, garden, or landscape, between feeding and trampling, in short order. Really high fencing (and I mean 7- or 8-feet high) might block deer. If your garden is on a slope, you will need fencing that is 10- or 11-feet high! Loud, scaring devices and various repellants can also be used to try and block these determined garden pests, but the effectiveness of these methods doesn’t last very long.


Mice

In California, we have deer mice, house mice, and meadow mice, also known as voles. Deer mice and house mice are mostly seed eaters that can wipe out a garden crop before it even starts. Voles are herbivores that will eat your bulbs, tubers, artichoke, beets, Brussels sprouts, celery, cauliflower, sweet potatoes, lettuces, tomatoes, turnips, cabbages… well, you get the idea. If that weren’t enough, voles will also chew the bark off your fruit and nut trees.

Moles and shrews

Shrews and moles may look like mice with deformed noses, but they are not rodents. They are more closely related to hedgehogs. There are 13 shrew species and 4 moles species in California, and they spend most of their lives underground, digging burrows and eating. For their size, shrews have voracious appetites, eating 1/2 to 2 times their body weight each day in worms, insects, and other invertebrates. They will also eat seeds, roots, and bulbs, but mice and pocket gophers are usually the culprits in those cases. Trapping is the most effective control measure, though chemical repellants and noisy, scaring devices can provide some protection.

Opossums

Opossums may look prehistoric, but they can do your garden a good service. While they will sometimes eat fresh fruit and vegetables, opossums much prefer rotting produce, ticks, slugs and snails. In my book, that makes them a beneficial visitor. If an occasional tomato is lost, well, it seems a fair price.

Pocket gophers

Pocket gophers spend most of their time underground, digging burrows that lead to many of your garden and ornamental plants. We have 5 gopher species in California and they all feed on roots from below. They will also grab a tasty plant and pull it below ground to enjoy in relative safety. In a single night, one pocket gopher can destroy an entire garden row. Gopher traps are your best control measure.

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Rabbits, hares, and pikas

Contrary to popular belief, rabbits are not rodents. They are lagomorphs. There, I said it. Now, what are pikas? And what’s the difference between rabbits and hares? Well, rabbits are smaller than hares, and hares, also known as jackrabbits, have longer legs and ears. Also, hares change color with the seasons, while rabbits do not. As for pikas, you probably won’t ever see them because they tend to live at elevations above the tree line, but they are cute. So are rabbits and hares - until they decimate your salad garden or other crops. Keeping rabbits and hares out of the garden is an unending battle. Since they can burrow, fencing alone is not enough. Raised beds with an exclusionary hardware cloth base may be your only real solution if these pests are feeding on your garden. ​

Raccoons

Raccoons are smart. And when they are not attacking your chickens or eating your pet’s dinner, they are probably busy eating your garden fruits, berries, nuts, corn, or other grain. Raccoons are attracted to compost piles, trash cans, and bird feeders. Raccoons may also try using your house, chimney, or garage as a nesting site. While young raccoons are adorable, these nests mean the presence of urine, feces, and disease-carrying parasites. Also, unlike opossums, raccoons tend to carry several diseases, such as roundworm, distemper, and rabies. Raccoons are best controlled with live traps. As a furbearer, raccoon pelts have value, so you can probably find someone who will be happy to discharge a trapped raccoon. Otherwise, you can discretely relocate your visitor somewhere more appropriate, and less destructive. Just be sure to check on your legal obligations before you get yourself in trouble.

Rats

Wherever you live, you probably have rats. The two most common types of rats are Norway, or sewer, rats and roof rats. These pests are filthy, destructive, and difficult to get rid of. Rats carry diseases, chew through electrical wires, and can damage your home, along with your garden. Roof rats prefer avocados, berries, citrus, and nuts, while Norway rats prefer meat and grain. Before you protect your garden against these pests, be sure that there are no points of entry to your home. Once your house is secure, then you can start trapping outdoors in earnest.
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Skunks

There are spotted skunks and striped skunks. In either case, it is a good idea to stay at least 10 feet away from the back end of a distressed skunk. [By the way, skunks have terrible eyesight. If you find yourself closer than you would like, be very, very still, or move away very, very slowly. A startled skunk is an unpleasant experience.] Both skunk species will eat pretty much anything: garbage, compost, pet food, worms, fruit, berries, mushrooms, beetles and other insects, lizards, frogs, snakes, and even the occasional bird egg. Since skunks are the most common carrier of rabies in California, along with distemper, canine hepatitis, leptospirosis, and several other diseases, getting them out of your garden (or out from under your porch) is a good idea. This is best done by professionals. Very often, your local Animal Control Office will remove skunks for free. Once a skunk family is removed, it is important to block whatever area, or remove whatever feature, attracted them in the first place. Otherwise, you will just get a new skunk. If you are unfortunate enough to be bit by a skunk, see your doctor right away. Seriously.


Squirrels

There are two major types of squirrels: tree squirrels and ground squirrels. If I didn’t have dogs, I would probably have nothing to show for all my work in the garden because of squirrels. I was surprised to learn that they will eat oranges, tomatoes, blueberries, pears, and more. Adding insult to injury, squirrels will, like birds, often only take a bite or two before moving on to the next delectable piece of fruit, leaving a trail of potential disease behind them everywhere they go. Hardware cloth and chicken wire are the only reliable barriers to squirrel feeding, though I have had some success with a repellant called Bobbex-R.

Finally, our pets.


We love our pets. There’s no denying that cats and dogs have a very special place in our hearts. That being said, we do not want cat feces next to our lettuces, or dogs digging up rows of beans or tomatoes. As much as your cat may love being outdoors, researchers at UC Davis have demonstrated that your cat is perfectly happy and actually safer kept indoors. Being stealthy predators, cats can decimate local bird, reptile, and amphibian populations, and we need those other creatures more than your cat needs time outside. Dogs can be trained to provide several beneficial services in the garden. My two dogs will chase squirrels, raccoons, rats, mice, opossum, jays, and cabbageworm butterflies out of my garden. Since most of my gardening is now done in raised beds, I don’t have to worry about the dogs running through them.


While we need to learn how to live and let live, there is nothing wrong with protecting what is yours.  This is especially true for disease carrying pests. In some cases, it is simply easier to fence in your crops with netting and tree cages. For those mammals in the garden that must be killed, please use the fastest, most painless method. 


How do you manage mammals in your garden?

Predaceous ground beetle life cycle

Eggs are laid in moist soil. When they hatch, larvae that look similar to earwigs emerge. These larvae feed voraciously on slugs and snails, and many bothersome soil dwelling insect larvae and pupa. These pest insects include masked chafers, caterpillars, grubs, tussock moth and gypsy moth larvae, other beetles, and maggots.

​While predaceous ground beetles will occasionally eat seeds and organic litter, they prefer meat to vegetables. In fact, adult Calosoma sycophanta (affectionately known as caterpillar killers) eat several hundred caterpillars in their 2 to 4 year lifespan, and their larvae eat up to 50 caterpillars before transforming into adults! While not exactly predaceous, Lebia grandis loves to feed on potato beetle eggs and larvae.


So, the next time you see a black beetle running across the patio, look for fat legs and eyebrow ridges before squashing it!

Cousin to the dreaded MedFly, melon flies, and spotted wing drosophila, just to name a few, Mexican fruit flies (Anastrepha ludens), or MexFlies, are a major agricultural pest. Quarantines are part of the ongoing battle against fruit flies, so it’s a good idea to check your state’s quarantine listing, or your local Department of Agriculture, periodically to see if your area is included.


History of Mexican fruit flies in the U.S.

First found in the U.S., in Texas, in 1903, Mexican fruit flies were seen again in 1927. By 1954, they had spread to Florida, Arizona, and California. It is estimated that these pests have cost farmers $1.44 billion in damages. Mexican fruit flies are subject to eradication programs that include capturing, sterilizing, and releasing males that interrupt the breeding cycle.


Mexican fruit flies have been expanding their range for several years now, and it’s not simply by catching a ride on an infested piece of fruit. Commercial agriculture brings crops to non-native regions, introducing them to local pests and diseases. For example, the mango, from India, only became a popular food of Mexican fruit flies after it started being grown in Central American and Mexico.


Host plants

Mexican fruit flies prefer grapefruit, oranges, tangerines, mango, apple, peaches, nectarines, avocado, and pear. More recently, they have been found on figs, bananas, prickly pear cactus, cashews, papaya, guava, pomegranate, peppers, tomatoes, squash, beans, quince, Japanese persimmon, passionfruit, pummelo, and arabica coffee. [Coffee?!!?} Not only is the Mexican fruit fly range expanding, but so is their diet.


Mexican fruit fly description

Slightly larger than a housefly, Mexican fruit flies are 1/3 to 1/2 of an inch long. They have a yellow or brown body and distinctive wing patterns. Also, adult females have extra long ovipositor sheathes (egg-laying tubes). The wing patterns include a costal spot (C), an inverted-V, and a sideways S shape. Larvae are slender white grubs with mouth hooks, and a slightly flattened back end.


Mexican fruit fly lifecycle

As far as fruit flies go, this particular species is relatively long-lived. Individuals can survive for 11 to 16 months.  Females lay over 1500 eggs in their lifetime. Eggs are laid in groups of 10, on the skin of a fruit, preferably one that is slightly damaged. This provides an easy point of entry for Mexican fruit fly larvae, along with many other pests and diseases. In a week or so, after being deposited, the eggs hatch out larvae that burrow into the fruit and start feeding. As they feed, the larvae take on the color of the fruit their are eating, so you may not notice right way, after taking a bite of an infected fruit.


​Larval feeding continues for 3 or 4 weeks, depending on temperatures. Then, larvae drop to the ground, where they pupate in the soil. During this seeming pause in development, the slug-like larva is converted into a winged adult that begins breeding immediately after emerging, starting the whole process over.


Controlling Mexican fruit flies​

Because they spend most of their lives inside fruit, insecticides are not effective against Mexican fruit flies in the larval, egg, or pupal stages. There is a tiny, repeated window of opportunity for treatment of adults, but only if direct contact is made with the insecticide. Generally, adults will simply fly away from treated trees and return a few days later, after it has worn off. Commercial growers use complex bait and trap methods that are unavailable to small scale growers.


So, the only thing you can do if you suspect that Mexican fruit flies have found their way to your garden is to immediately contact your state's Pest Hotline, or your local Department of Agriculture. It is best to leave controlling these pests to the pros.

Melon flies could end up costing California farmers over $4.5 billion if they ever get a toe-hold in the state.


Melon flies (Bactrocera cucurbitae) are a type of fruit fly. Native to India and Asia, melon flies were first seen in Hawaii in the late 1800’s. They have now become a devastating pest on the Islands. Quarantine stations have worked long and hard to prevent this pest from entering the Continental U.S. The melon fly was first seen in California in 1956, and several other times since, but whenever melon flies are identified stateside, eradication programs immediately go into affect. These programs use pheromones to attract male melon flies. These males are then sterilized and released. This messes up melon fly breeding. So far, this method has been effective. So, why would a gardener care, if the pest isn’t even here? Because maybe it is.

Beneficial biter

Despite their bite, insidious flower bugs really are beneficial. They feed heavily on thrips [their favorite food], corn earworm eggs, mites, spider mites, small caterpillars, bollworms, whiteflies, scale insects, European corn borers, armyworms, potato leafhoppers, and a slew of aphid varieties, including spotted tobacco aphids, corn leaf aphids, and potato aphids. Insidious flower bugs are so beneficial, that they are raised commercially as a biological control against thrips, European red mites, twospotted spider mites, and most aphid varieties in eggplant, strawberry, cucumber, and sweet peppers crops. Research conducted in Florida found that insidious flower bugs were more effective at controlling thrips on sweet peppers than insecticides. Other research has demonstrated similar results with twospotted spider mites on bean plants, and soybean aphids on soybeans.


​Insidious flower bug description

These mixed blessings are small, only 1/5 of an inch long. They tend to be flattened, with an oval to triangular shape. They are black with white markings. Nymphs are yellowish-orange to brown, wingless, and teardrop shaped. If you look at an insidious flower bug under a microscope, you can see that they have piercing mouthparts, called beaks, which they use to repeatedly stab and suck the juices from their prey.


Orius insidiosus lifecycle 

​Insidious flower bugs seem to come out of the woodwork in late summer, though they have been around since they hatched, starting in spring. Eggs are laid in plant tissue, then hatch into nymphs, going through five instars before reaching adulthood. This takes approximately 20 days, and there can be several generations a year. Most of their diet consists of insects and insects eggs, but they occasionally eat plants and pollen when prey is scarce.


​Attracting insidious flower bugs

Despite the bite potential, these predators are good to have around. You can attract them to your garden by growing alfalfa, buckwheat, soybeans, cotton, grapes, and most deciduous fruits.


You can reduce the chances of getting bit by wearing dark clothing on hot days in late summer. For the most part, insect repellants do not work against these garden visitors.

aAlso known as black ladybirds and Forestier’s ladybird, Rhyzobius forestieri is a true garden hero when it comes to fighting scale insects.


Black lady beetle description

Black lady beetles are smaller than our common red ladybug. You could fit 5 or 6 of them across the top of a dime. If you look closely, you will see that their dark brown or black bodies are covered with tiny, short hairs. They have dark legs and tan antennae. If you were to flip one over, you would see that the underside is also tan. Adult and larval forms of black lady beetle have 3 pairs of legs and adults can fly.


Black lady beetle have the same alligator-like shape as common ladybug larvae but they are more gray. Pupal cases look a lot like tiny snail shells.


Black lady beetle lifecycle

Nearly microscopic eggs are laid next to, under, or up against scale insects. When the eggs hatch, they begin feeding on scale insects as they go through four developmental stages, or instars. Ultimately, they enter a pupal stage. When adults emerge from the pupal case, they mate and the whole cycle begins again.


The next time you see a tiny black beetle, make sure it’s not one of the Good Guys before squishing it!

Damage caused by medflies

Medflies lay their eggs in the skins of over 250 different fruit, nut, and vegetable crops. When the eggs hatch three days later, the maggots burrow into what we normally eat, making it inedible. Once maggots have eaten their fill, either the rotting fruit falls, or they drop to the ground where they pupate in the soil. In one week, an adult emerges and the whole cycle begins again.


Crops affected by the medfly

It would probably be easier to list the crops not affected by medflies, but this should give you an idea: apples, apricots, avocados, cherries, figs, grapes, grapefruit, lemons, limes, melons, nectarines, oranges, peaches, pears, persimmons, plums, pomegranates, sweet peppers, tangerines, tomatoes, and walnut.


The ripple effect

Like most things in life, this situation is not limited to bug-infested food plants. Commercial and home growers will end up using more pesticides to counteract this insect, which can lead to more ground water contamination and chemical resistant pests. Also, areas with medfly populations are unable to sell their produce, infested or not, to other states and other countries. Finally, native plants that produce fruit or nuts can also be attacked by this pest.


Medfly controls

The first appearance of a medfly in California took place in 1975. I remember hearing about it in the news - everyone was talking about it. The government declared a “state of emergency” and 100 square miles were placed under quarantine, and 600 million sterile male medflies were released to interrupt breeding. Malathion was sprayed all over the place. It cost $1 million and took a year, but the medfly was eradicated. For a time.


When the medfly returned in 1981, Governor Brown delayed aerial spraying of malathion, claiming environmental concerns. That was when we learned that medflies reproduce and feed at astounding rates. In that case, the medflies needed only one month to destroy millions of dollars of crops, and to threaten billions more, over an area of 530 square miles. When it was realized just how devastating this pest could be, the California National Guard was called upon to create highway checkpoints to confiscate infested produce.


Now, when a single medfly is spotted, it is checked for gender and fertility, and then all the stops are pulled: aerial spraying, ground spraying, trapping, irradiation, releasing sterile male medflies, public information, and quarantines. Since 1985, medflies have been found in California in 2007 (Dixon), 2008 (El Cajon), and in 2017.


What can you do?

First, never, ever, EVER smuggle fresh produce, plants, or soil from infested areas into uninfested areas. Do not mail fresh produce into uninfested areas either. For more information, contact the California Dept. of Food and Agriculture at (650) 363-4700.

Robber fly description
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There are over 7,500 different species of robber fly, ranging in size from 0.2 inches up to 2 inches long. All of them are sturdy, bristled flies with a distinct mustache, made of of bristles (setae), called a mystax. Robber flies, like many other insects, have three simple eyes (ocelli), in a depression on top of their head, between two very large compound eyes. [Simple eyes, like ours, have only one lens, while compound eyes have many lenses.] Robber flies generally have robust legs with spines, and short, segmented antennae. Most species of robber fly have long, skinny bodies with stinger-like ovipositors, while others look more like bumblebees. Robber flies will inflict a painful bite with their proboscis (tubular mouth part), if they feel threatened.

Robber fly life cycle

There is surprisingly little known about the private lives of robber flies. They seem to prefer dry, sunny, open environments. Each robber fly can live for up to 3 years. Eggs can be translucent (hyaline) or pigmented, spherical or oval, depending on the species. Yellowish or white larvae, with tapered bodies and a dark head, are believed to live in leaf mold, rotting wood, and in the soil. There are four larval stages, or instars. Scientists are only now learning about the feeding behavior of robber fly larvae. It’s pretty strange. For one thing, the first instar does not eat insects; it probably eats dead things. The second instar eats beetle larva secretions. [Don't ask.] Later instars are actual predators. Robber fly pupa are naked and have leg stubs, so they can move around, similar to hornworm larvae.


Robber fly prey

Robber flies are generalists. That means they will chase after and kill pretty much anything that flies by, beneficial or not. That is why I said, for better or worse.” Robber flies will kill many garden pests, but they will also kill beneficial insects. Some of these prey insects are pretty substantial in size, compared to a robber fly. But, adult robber flies are excellent fliers. You can usually hear them coming, but for their prey, it’s already too late. Hiding in ambush, a robber fly spots its target, gives chase, and grabs ahold with its tarsi (front legs) before injecting a chemical cocktail that paralyzes the prey and liquifies its insides. The most common victims of robber fly attack include:

• ants, bees, wasps, sawflies (Hymenoptera)
• butterflies, moths (Lepidoptera)
• beetles (Coleoptera)
• flies, crane flies, horseflies (Diptera)
• grasshoppers, crickets, katydids (Orthoptera)
• leafhoppers, stinkbugs, aphids (Hemiptera)

They have also been recorded feeding on:

• dragonflies, damselflies (Odonata)
• lacewings, antlions (Neuroptera)
• spiders (Arachnida)
• termites, cockroaches (Blattodea)
• thrips (Thysanoptera)

And, hummingbirds. It’s rare, but it has happened. You can see some excellent video of robber fly behavior at Mike Blair Outdoors.


Have you seen any robber flies in your garden? Do you consider them to be Good Guys or Bad Guys?

Hoverflies are members of the Syrphidae family. There are over 6,000 species worldwide and 300 on the West Coast. Many of them mimic bees and wasps to discourage predators, but they are harmless to humans. Hoverflies mimic bees and wasps in other ways, too, as both predators and pollinators.

Hoverfly description

With so much variety, there is no one description that covers all hoverflies (also spelled hover flies). They can be as large as 3/4” long or so small that you won’t notice them. They can be black or colorful, spotted, striped, or plain. What they all have in common is the fact that they tend to hover over their favorite flowers. There are some bee flies that also hover, but they are equally beneficial as both pollinators and predators, so you don’t really need to know the difference* between the two species.

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* If you really need to know the difference, hoverflies have shorter legs, a prominent beak, and a line along the back of their wings, while bee flies have longer legs, a sloping face, and clear wings.  Also, bee flies are more likely to be hairy. There. Now you know.

​Hoverfly larvae are blind and deaf. They are only 1/32 to 1/2 of an inch in length. They may be green, brown, yellow, or nearly transparent. They may have a white longitudinal stripe.

Hoverfly behavior

Not all hoverflies behave in the same way, but there is enough variety to safely assume these are bugs you want in your landscape and garden. Some hoverfly larvae are saprotrophs, which means they each decaying plant and animal matter in the soil. This improves soil structure and makes nutrients available to plants. Other hoverfly maggots are powerful predators, devouring a lion’s share of aphids and other plant-sucking pests.


Hoverflies as predators

Most hoverfly species larvae will eat aphids, thrips, mealybugs, mites, scale insects, and leafhoppers. That’s a good thing, because these pests spread several diseases, including curly top, powdery mildew, black spot, rust, and sooty mold, just to name a few! Other hoverfly larvae prey on caterpillars, slugs, and codling moth larvae. In my book, there are no bad hoverflies.


Hoverflies as pollinators

As adult hoverflies feed on nectar and pollen, they also pollinate many of your garden crops. In fact, hoverflies are second only to bees when it comes to pollination. Unlike bees, which tend to prefer specific species, hoverflies are generalists, landing wherever the picking looks good.


Attracting hoverflies

There are several insectary plants that attract hoverflies. Most of these plants provide pollen and nectar to the adult forms. Hoverflies prefer plants that have shallow or umbrella-shaped flowers. These plants are often members of the Umbelliferae or Apiceae family. Adding the following plants to your landscape is sure to attract these beneficial insects:

Research has shown that hoverflies prefer yellow and white flowers over other colors. Since organic pesticides, such as spinosad, also kill beneficial hoverflies, you may want to think twice about when you spray. Once flowers are in bloom, you may want to hold off.


Orchid trivia - One type of orchid, Epipactis veratrifolia, emits chemicals that mimic the alarm pheromones used by aphids. This attracts hoverflies, resulting in pollination. Stuff like that makes me wonder what else is going on that we never notice.

Birds in the garden: boon or bane?


The answer: both.


The presence of birds in a landscape indicates a healthy biodiversity. They eat many garden pests and may even help with pollination. That being said, birds can be a Royal Pain. They destroy seedlings, devastate crops, and can carry disease. Bird management can reduce the problems while increasing the benefits.


Benefits of birds
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The image of a red-breasted robin tugging an earthworm from the soil is an icon of spring. Birds also eat crane flies, stinkbugs, armyworms, moths and their caterpillars, millipedes, spiders, slugs and snails, crickets and grasshoppers, inchworms, katydids, grubs, cabbage loopers, cabbageworms, and countless other garden pests. You may be surprised to learn that hummingbirds often eat spiders, gnats. flies, and ants, especially when they are raising young. Some birds eat the mosquitoes responsible for Zika virus, along with several other diseases. Birds facilitate decomposition by eating foods and then leaving nutrient-rich droppings behind. As birds eat the seeds of fruits and other garden crops, they help spread seeds for future crops.

Birds as pests

As birds devour garden pests, they will also eat beneficial earthworms, centipedes, bees, and butterflies. But crop damage is the real problem. Birds love seeds, fruit, and nuts. They will dig up seeds, devour seedlings, peck holes in fruit, and decimate nut crops. They are particularly fond of pea, bean, melon, and squash seeds. Birds can be major pests if you are growing hazelnuts, almonds, figs, pears, peppers, peaches and nectarines, apples, blueberries, blackberries, raspberries, grapes, saffron crocus or other bulbs, sorghum, or tomatoes. They can wipe out amaranth and quinoa crops. Birds can also carry diseases, such as San Jose scale. Scrub jays will steal eggs from your chickens and kill young chicks. Birds can also be troublesome when it comes to soil solarization. As they search for grubs and worms, they may lift the fabric, halting and reversing the solarization process. Finally, woodpeckers and sapsuckers can effectively girdle a tree as they feed if the holes are too numerous and go all the way around a tree trunk.


Birds and mixed crops

Some crops, such as sunflowers and currants, can be used to support biodiversity in the garden while still providing a harvest for your family. Fruit from currant bushes, and the seeds and leaves of sunflowers, are popular foods for many indigenous birds, especially goldfinches. You can protect your crops by placing paper bags over flower heads and fruit clusters, or you can simply grow more than you need and provide food for our feathered friends.


Local bird dilemma

Many European birds, such as sparrows and starlings, have made life difficult to nearly impossible for many of our indigenous birds. They take over habitat and food supplies, and are less fearful of humans, so our native birds are suffering. Bluebirds, goldfinches, and several wrens are being pushed into marginal habitats by these interlopers. In addition to habitat loss, they are also facing chemical toxins, cars, windows, plastic garbage, and improperly used netting. Their young are also vulnerable to squirrels, outdoor cats, and other predators. You can help these birds by installing native plants, providing a water source, and constructing bird houses with very small (1” diameter) openings. Anything larger and sparrows will pitch the eggs, kill the young, and take over. Birdhouses need to be placed on poles to be appealing to our native birds. Birdhouses hung from buildings and fences will not be used because they are vulnerable to predation.


Bird management

To reduce the damage caused by birds in the garden, tree cages can be erected around fruit and nut trees. These structures a much easier to build than they sound, and cost very little. You can also protect newly planted seeds and seedlings with row covers.


Birds are a mixed bag, but it wouldn’t be a healthy landscape without them.

Nocturnal brown moths (Trichoplusia ni) fly in at night and lay tiny hemispherical eggs, singly or in clusters, on upper and lower leaf surfaces. Adult moths live 10 to 12 days. Females can lay 300 to 600 eggs in that time. Two to ten days alter, pale white larvae emerge and begin feeding on the underside of leaves of cabbage, broccoli, and other members of the brassica family. As the loopers grow, they move to the upper side of leaves and feed heavily, leaving large ragged holes. They also feed on tomatoes, kale, radish, lima beans, lettuce, peas, peppers, beans, spinach, squash, sweet potatoes, watermelon, cucumbers, potatoes, thyme, and collard greens, leaving behind clumps of dark green droppings.


Cabbage looper description

​There are actually several different cabbage looper species, usually based on their favorite food. All cabbage looper larvae reach 1-1/2 inches long and end up pale green. They start out white but, as they feed, they turn green. They move in a classic ‘looping’ inchworm motion. The adult moth is brown.

Cabbage looper control

Unlike other inchworm larval forms, cabbage loopers are resistant to Bacillus thuringiensis (Bt). Luckily, they have many natural predators in the form of big-eyed bugs and parasitic wasps. Avoiding the use of broad spectrum pesticides can help these beneficial insects protect your crops. Hand-picking cabbage loopers can also reduce damage.

Oleander aphid description

Like other aphids, this species is small (1.5 to 2.6 mm), pear-shaped and soft-bodied. Oleander aphids, in particular, are bright yellow, with black legs, wings, and cornicles. Cornicles are tiny spikes on an aphid’s back that can excrete defensive fluid. [My dog did that once, after he got into some old pork bones. It wasn’t pretty.] Actually, these defensive fluids are cardiac glycosides that the aphids take from their host plants! Cardiac glycosides are known heart poisons. Luckily, these pests cluster on new stems and are easy to spot. And those defensive fluids won’t hurt you.


Aphid lifecycle

As much as I dislike aphids for their plant-damaging and disease-carrying capabilities, I have to give credit where it is due. These soft-bodied bugs really are amazing. Female aphids (and almost all of them are female) are viviparous and parthenogenetic. Wait! Come back! Let me explain. Viviparous means that offspring develop within the mother, the way we do. Parthenogenetic means fertilization by a male is not needed to produce offspring. Not like us. Most aphids do not have wings. But, when they become too crowded, or when a plant starts senescing (dying), some adult aphids emerge with wings. That would be something like all human beings being born 40% smaller, simply because we start running out of room and resources. Hmmm… But I digress. Let’s get back to aphids.]

Katydids are cousins to crickets, grasshoppers, and mole crickets, and you might not want them in your garden or landscape.


There are over 250 different species of katydid in North America (over 2,000 species worldwide). The name ‘katydid’ refers to the sound made by males when they are trying to attract receptive females.


Katydid identification
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Katydids can be difficult to see. It’s not that they are small, because they aren’t. Mature katydids can range from 1/2” to nearly 5” in length! The difficulty lies in their resemblance to leaves and the fact that they are mostly nocturnal. During the day, they hide out in trees and shrubs, blending with the foliage. They tend to have a bright green, blade-like body, with large hind legs. They look a lot like flattened grasshoppers, but with extra long antennae (or ‘horns’). Very often, the only notice you will get that katydids are present is the damage they cause and a male’s strident chirp.

Katydid lifecycle

Katydids (Tettigoniidae) start out as oval-shaped eggs that are laid in rows, at the end of summer, in the soil and in host plant stem holes. These eggs often hatch out looking like tiny adult katydids with big heads and small wings. Nymphs of some species of katydid mimic spiders or leaf-footed bugs in their early stages of development to avoid being eaten. As they feed and grow, they shed their outer exoskeleton and go through several instars before reaching adult size. As summer nears its end, males start singing to attract females. Females use the volume and fluency of a male’s chirp to judge his fitness level. In order to ensure a healthy pregnancy for the female, male katydids provide their (temporary) mates with a ‘nuptial gift’ of sperm and highly nutritious food.