Garden Insect Control -- I Can Help!
Know the Insects In Your Garden
Garden insects can be beneficial, or they can be very, very harmful. It helps if you know the difference between garden insects that pollinate and protect your garden, and those that are out to gobble up every single leaf and flower they can find. In every climate and in every habitat there are insects that pose challenges to gardeners. To stay ahead of these garden pests you need to know what these insects are and how they behave -- in other words, you need to know who you're dealing with. Knowledge is power! Every insect pest that is busy munching on your garden has a set of behaviors that are the key to your success in controlling them. If you take the time to learn a little about the insects in your garden, your garden insect pests can be controlled, often without toxic chemicals or labor-intensive methods.
Aphids, Grubs, Japanese Beetles, and Hornworms
Don't let these insects eat up all of your hard work this year! When you know what to look for, you can help save yourself from some of the most destructive garden insects. There are many different insect pests that attack your garden during the growing season. This article will focus on a few of the most common, and the most destructive.
Garden Insect Control: Aphids
Aphids are small insects in the order Hemiptera, otherwise known as the "true bugs" -- so calling these little critters "bugs" is scientifically accurate. There are several families of aphids within the superfamily Aphidoidea, including Mindaridae, Pemphigidae, Phloeomyzidae, and Thelaxidae. Aphids typically occur in large numbers, clustered near the top of plants. They use their piercing mouthparts to suck tiny amounts of juices from plants they attack -- but since there are so many of them, the cumulative effect on your plants can be devastating.
Garden Insect Control: Aphids and Ants
One reason your aphids can be tough to get rid of is the symbiotic relationship they have evolved with ants. Ants are aggressive protectors of aphids because aphids release a substance, called "honeydew," that the ants feed on. As a result, ants tend to aphids in much the same way farmers tend to cows -- they harvest the honeydew, and in return protect the aphids by chasing away or killing predators. Ants are in the same order as wasps (Hymenoptera), and will sting and bite to protect their aphid "herd."
Aphids versus Ladybugs
One good option for controlling aphids in your garden is to introduce ladybugs. Ladybugs are actually beetles -- another name is "ladybird beetle" -- of the family Coccinellidae. Despite their quaint name, they are ferocious predators of many aphid species. Both the highly visible black and red beetle and the larvae, which look a little like tiny lizards, will attack aphid colonies and can be effective natural control methods.
Garden Insect Control: Grubs
Grubs are the immature form of beetles (Order Coleoptera). The kind that does damage to your lawn and plants are often members of the Scarabaeidae family, a very large group that includes some of the world's largest and most attractive insects. Unlike these, lawn grubs grow up to be plain brown beetles known in some parts of the country as May beetles or Junebugs. The adults are generally harmless and eat relatively little, but the grub stage can do damage by feeding on roots just below the surface. You probably won't even see them unless you 're doing yard work, but you can tell if you have grubs by unexplained die-off in grassy areas or among garden plants.
Unfortunately, one of the most popular ways to control grubs is to use chemicals. Many of the products out there don't even work because they don't get down into the soil where the grubs are. For example, products containing lambda-cyhalothrin, gamma-cyhalothrin, bifenthrin, deltamethrin, cyfluthrin and permethrin are generally going to be a disappointment when it comes to grub control because they don't get down into the soil where the insects are.
There are, however, a fair number of products containing imidacloprid and other substances that do reach under the surface. When applied according to directions these can control grubs - though it is important to start early in the season. Remember, you aren't likely to see the grubs themselves, just the damage. If you wait to long the damage will be done and the grubs will be on their way to becoming beetles.
Garden Insect Control: Japanese Beetles
Japanese beetles, otherwise known as Popillia japonica, are one of the most significant pests in North America. They are native to Japan, where a number of natural predators keep the species in check. Since being introduced by accident in 1916 in a New Jersey nursery, the Japanese beetle has spread nearly everywhere in North America, attacking upwards of 200 species of plants, including rose bushes, grapes, hops, canna, crepe myrtles, and others.
Lacking natural predators here, the beetle has been able to grow without challenge. Finding efficient natural, or even chemical control methods has proven to be nearly impossible.
Are There Japanese Beetles Where You Live? - Range of Japanese Beetles in the US
The Japanese beetle was first found in the United States in 1916 in a garden nursery in New Jersey. Since then it has spread across much of the country, eating as it goes.
[Public domain], via Wikimedia Commons
Leaf Damage Typical of Japanese Beetles
Options for Control of Japanese Beetles
There is a pathogen called "milky spore disease" that is deadly to Japanese beetles. Milky spore is a naturally occurring host-specific bacterium (Bacillus popillae-Dutky), that acts as a natural control vector for P. japonica. Since the immature grub of the beetle feeds in the ground, applying this substance to the ground reaches and kills the grub.
In addition, Commercially available traps can help manage Japanese beetles. Some of these are listed below.
Garden Insect Control: Kill Japanese Beetles Without Spraying!
Japanese beetles are a serious pest that can really chew up your rose bushes, not to mention just a out any other plant. They are an invasive species that has few natural predators here and pose a serious threat to our ecosystem. These passive attractant traps draw Japanese Beetles into a container using pheromone bait. You never have to handle or even see the dead beetles -- just dispose of the container and set out a new one.
This method is used by professional biologists and entomologists to attract and assess pest insect populations.
Garden Insect Control: Tomato Hornworms
These large caterpillars are the larval stage of Manduca quinquimaculata, or the tomato horn worm moth, which is a member of the Sphingidae family in the order Lepidoptera. They commonly show up in mid to late summer, when tomato vines are just starting to bear fruit. They are quite large and heavy, but can still be hard to find among tomato plants thanks to their excellent camouflage. It is unusual to find just one of these garden pests, since the female moth typically lays dozens of eggs on the plant -- in other words, if you find one, don't stop looking, since more are almost certainly nearby.
By Khanm83 (Own work) [Public domain], via Wikimedia Commons
Control of Tomato Hornworms
Chemicals and pesticides are notoriously ineffective against hornworms, but there are other measures that do work well. One of these is the application of talcum powder. The dust clogs up the insects' spiracles, the holes along the side of the body through which they breathe. You may also want to enlist your family and friends to go on a seek and destroy mission, since it often takes more than one pair of eyes to find every caterpillar. Another option is to soap your plants with an anti-insect soap -- but be sure to get a quality product, since there many "anti-insect soaps" out there that are really nothing more than a little diluted dish soap in an expensive spray bottle...