Insect Pests
Insect pests are attracted to our herbs by the very same assets which attract us; their wonderful scent and beauty. They damaging insects can be controlled without the need of spraying toxic insecticides on the herbs which we will harvest to flavor our favorite pizza or pasta dish! Many beneficial insects which are natural enemies of the insect pests in our herb gardens are available online.
Aphids
Aphids are small, winged insects that can be green, yellow, brown, orange or black in color. They feed on the juices they suck from the herbs. Aphids congregate on herbs where they feed on the most tender and freshest growth.
They can be controlled organically through the use of insecticidal soaps or preferably by the use of the many beneficial insects which feed on the pest. The primary insects of choice used to provide control are the Assassin Bug, Damsel Bug, one of the many species of Big-eyed Bug, Lady Beetle and Lacewing Larvae, to name a few.
whitefly
Whitefly is a pure white little bug about .8mm long and feeds on the undersides of the plant leaves by penetrating the under leaf surface with its piercing-sucking mouth parts. Adults congregate and fold their wings over their bodies while at rest or feeding. They can occur in such numbers that when disturbed they may create white, very irritating “bug clouds" in gardens and green houses. They appear to be more active during the day, but not as active during the early morning, late evening or at night.
Feeding damage by both the nymphs and adults results in the accumulation of a sugar-rich sticky substance deposited on the leaves known as honeydew, a euphemism for bug excrement. The presence of honeydew can promote the subsequent growth of telltale sooty black mold. Other forms of damage include the removal of plant sap. It is believed that the pest injects foreign enzymes into the host plant while feeding, affecting the normal physiological processes.
Japanese beetle - popillia japonica
Japanese beetle is slightly over ½ of an inch long (1.5 cm) and almost ½ inch wide (1 cm) with iridescent copper-colored wings and green body and head. With its western spread across the United States it has become a serious pest of about 200 species of plants.
The Japanese beetles damage plants by consuming only the leaf material between the veins of the plant leaf, leaving only a skeleton behind. During the larval stage, the Japanese beetle lives in lawns as a grub worm, consuming the roots of grass.
Natural repellents include catnip, chives, garlic, and tansy. When present in small numbers, the beetles may be manually controlled using a soap-water spray mixture.
Mealy bugs
Mealy Bug is the common name of insects in Pseudococcidae, a family of unarmored insects found in warmer climates. They feed on plant juices of greenhouse plants and house plants.
Mealybug females are wingless, though unlike many female scale insects, they retain legs and can move. They secrete a powdery wax covering (the name mealy bug) used for protection while they feed on the plant juices, normally in crevices of the host. The males do not feed as adults and are short-lived as they only survive to fertilize the females.
Mealybugs have many natural enemies, however, ants feed on the mealybug honeydew and will actually protect them from predator and parasites. For this reason, mealy bugs only tend to be serious pests in the presence of sufficient numbers of ants. Mealybugs have a natural coating that repels insecticidal soap. They can be suffocated using an Insecticidal Oil, or daub them with rubbing alcohol on the end of a cotton swab.
Thrips
Thrips are tiny, brown or tan, slender insects about one-eighth of an inch long, with fringed wings. They're very narrow, appearing the shape of a tiny alligator. Thrips are generally are not good flyers, although they can be carried long distances by the wind. In the right conditions, many species can explode in a swarm making them an irritation to humans.
Thrips are difficult to see with the naked eye, but their damage is very clear. Thrips feed on a large variety plants by puncturing the surface and sucking the contents. Thrips also chew the top surface of leaves, leaving a striped, tan dead layer of leaf behind. The damage can appear as ‘white spots', or a lacy or skeletal appearance on the leaves.
Due to their small size and high rate of reproduction, thrips are difficult to control using classical biological control. The predators must prey extensively on eggs and larvae and also be small and slender enough to penetrate the crevices that thrips hid in while feeding. Only two families of parasitic insects are known to parasitize the eggs and larvae of Thrips: the Eulophidae and the Trichogramma (Trichogrammatidae). Other biocontrol agents of adults and larvae include aphid wasps, anthocorid bugs of genus Orius, and Phytoseiid mites. For this reason, many growers are occasionally forced to make limited use of pesticides to control thrips populations in the field and in greenhouses.
On a small scale Insecticidal Soap will kill thrips very effectively. Repeat about every three days to kill young trips hatching from existing eggs on the plants.
Spider Mites
Spider Mites generally live on the under sides of leaves of plants, where they can cause damage to several hundred species of plant, by puncturing the plant cells to feed.
Hot, dry conditions are often associated with population build-up of spider mites. At 80ºF and above, the two-spotted spider mite can hatch in as little as 3 days, and become sexually mature in as little as 5 days. One female can produce and lay around 20 eggs per day and over a period of a few weeks can lay hundreds of eggs. Her offspring can baloon into a population of a million mites within a month.
Spider mites have a variety of natural enemies in the bug world making the organic control of this pest relatively easy for the herb grower. Pirate bugs (family Anthocoridae), big-eyed bugs (Geocoris) and several species of lady beetles are important natural enemies. Get live lady bugs! Shipping included from Arbico Organics! Click Here!
fungus gnats
Fungus gnats are small, dark flies whose larvae feed on plant roots or fungi and aid in the decomposition of organic matter. The adults are 2-5 mm long, and are important pollinators, and can also help spread mushroom spores.
Fungus gnats are very irritating to humans but harmless to otherwise healthy plants. Fungus gnats in the area of your indoor plants is generally an indication of overwatering. The gnats may be attracted to fungus growing in saturated top soil or may be feeding rotting roots that have been sitting in water too long. Draining the excess water and allowing the soil to dry is a good deterrent.
An effective deterrent is a yearly bath in insecticidal soap or applying an indoor mulch to the top of your houseplant soil. An organic repellent is the use of Neem oil diluted four teaspoons per gallon of water and applied at three ounces per square foot of soil.